Existing Annotations Review

GO Term	Evidence	Action	Reason
GO:0007286 spermatid development	IBA GO_REF:0000033	ACCEPT	Summary: Accepted as a core biological process. The propagation was checked in all three of the ways this campaign has found defects, and came back clean in each. (i) The donor MGI:MGI:3605549 resolves to UniProtKB G3UZ78, ADGB_MOUSE, Swiss-Prot reviewed, 1657 aa - the true 1:1 ortholog of the 1667-aa human protein, not a paralog. (ii) A paralog transfer is structurally impossible on this node: PANTHER PTHR46298 "Androglobin-like" has exactly two reviewed (Swiss-Prot) members, human ADGB and mouse Adgb, both in subfamily PTHR46298:SF1, so there is no divergent clade member that could donate the wrong biology. The family's cached total is 1670 proteins over 3237 taxa; the count of two is the reviewed subset and is stated as such. (iii) Asking not merely whether the donor carries its own evidence but which term it carries, QuickGO shows mouse Adgb holds GO:0007286 by its own IMP from PMID:36995441 - the identical term, neither above nor below the propagated one - so no downward MODIFY is warranted. Human patient genetics corroborates the transfer independently: bi-allelic ADGB variants cause asthenozoospermia and oligoasthenoteratozoospermia with malformed spermatids. Reason: Sole-ortholog donor carrying its own experimental annotation at exactly this term, in a two-member reviewed family with no paralog risk, and corroborated by human genetics. Propagation Review Root cause: NO FAILURE CORE Sources checked: MGI:MGI:3605549 · mouse Adgb (UniProtKB G3UZ78, ADGB_MOUSE, reviewed/Swiss-Prot, 1657 aa) SUPPORTS TRANSFER True 1:1 ortholog, resolved via UniProt xref:mgi-3605549 using the bare numeric id (the doubled MGI:MGI: form returns HTTP 400). It carries its own IMP to this exact term from PMID:36995441, so the propagation neither over-reaches nor lands above its donor. PANTHER:PTN002922608 · PANTHER internal tree node in PTHR46298 (Androglobin-like) SUPPORTS TRANSFER An internal tree node, not a protein. Recorded as such rather than as unresolvable. Note the two CC rows on this gene use a different node, PTN002922607, so PAINT placed the BP and CC terms at separate nodes within a family whose reviewed membership is only human and mouse ADGB. Supporting Evidence: PMID:35700329 it locates to the sperm flagellum, the annulus, and the midpiece, and that it is crucial for male fertility and sperm formation PMID:38385883 the spermatozoa from patients harboring ADGB variants showed multiple acrosome and flagellum malformations under light and electron microscopy
GO:0097225 sperm midpiece	IBA GO_REF:0000033	ACCEPT	Summary: Accepted. Same sole-ortholog donor as the spermatid-development row, and the donor holds GO:0097225 by its own IDA from PMID:35700329 - the same term, not a parent, so the ACRV1-style "propagation landed above its donor" defect is absent here. The mouse study localised Adgb along the whole flagellum including the midpiece by immunofluorescence in stage-12 and stage-15 spermatids and in epididymal sperm, and UniProt records the same placement. The donor's qualifier is located_in while PAINT uses is_active_in; that is the normal PAINT convention for a component where the gene product acts and is not worth a MODIFY on its own. Reason: Ortholog donor with its own IDA at precisely this term; localisation independently recorded in UniProt and reproduced in human spermatogenic cells. Propagation Review Root cause: NO FAILURE CORE Sources checked: MGI:MGI:3605549 · mouse Adgb (UniProtKB G3UZ78, ADGB_MOUSE, reviewed/Swiss-Prot, 1657 aa) SUPPORTS TRANSFER Carries GO:0097225 by IDA from PMID:35700329, the identical term. Checked for the ACTR8-style complex projection: that reference annotates 8 annotations over only 2 distinct entities (Adgb and Sept10) and its phenotype terms stay on the perturbed gene, so it is parallel per-protein curation, not a projection. PANTHER:PTN002922607 · PANTHER internal tree node in PTHR46298 (Androglobin-like) SUPPORTS TRANSFER Internal tree node, not a protein. Shared with the sperm-annulus IBA row. Supporting Evidence: PMID:35700329 it locates to the sperm flagellum, the annulus, and the midpiece, and that it is crucial for male fertility and sperm formation file:human/ADGB/ADGB-uniprot.txt along the whole sperm flagellum. Detected in the annulus of the sperm
GO:0097227 sperm annulus	IBA GO_REF:0000033	ACCEPT	Summary: Accepted. The donor holds GO:0097227 by its own IDA from PMID:35700329, again the exact term. This is the most specific and most informative of the three localisations: mouse Adgb and Sept10 co-localise in the annulus of stage-15 spermatids and mature sperm, and loss of Adgb mislocalises Sept10, which is the mechanistic link between the localisation and the manchette/annulus phenotype. UniProt records the same annulus localisation. Reason: Ortholog donor with its own IDA at precisely this term, and the annulus is where the gene's best-characterised interaction and phenotype are located. Propagation Review Root cause: NO FAILURE CORE Sources checked: MGI:MGI:3605549 · mouse Adgb (UniProtKB G3UZ78, ADGB_MOUSE, reviewed/Swiss-Prot, 1657 aa) SUPPORTS TRANSFER Carries GO:0097227 by IDA from PMID:35700329, the identical term. PANTHER:PTN002922607 · PANTHER internal tree node in PTHR46298 (Androglobin-like) SUPPORTS TRANSFER Internal tree node, not a protein. Shared with the sperm-midpiece IBA row. Supporting Evidence: file:human/ADGB/ADGB-uniprot.txt along the whole sperm flagellum. Detected in the annulus of the sperm
GO:0004198 calcium-dependent cysteine-type endopeptidase activity	IEA GO_REF:0000002	REMOVE	Summary: Removed. This is the textbook case of a domain's name being propagated into an activity, and the removal is argued positively rather than merely asserted. Three independent lines converge, and two of them do not depend on my alignment at all. First, the residues. Aligning the catalytic domains of six reviewed reference calpains (CAPN1, CAPN2, CAPN3, CAPN7, CAPN10, CAPN15) to ADGB 70-411 under four substitution and gap models, and reading the ADGB residue in each column anchored on the reference's own UniProt Active site feature, gives a sharply split result. The nucleophile cysteine is retained: 11 of 15 aligned columns have a Cys in ADGB and it is always the same residue, C132, with the ADGB position invariant even though which reference reaches it varies by model. The general base histidine and the asparagine are not: 1 of 22 and 0 of 22 respectively, scattered over seven and six different ADGB positions, and the single His hit appears under one model only at a position no other model selects. A papain-fold cysteine protease cannot turn over without the general base that deprotonates the nucleophile, so a retained Cys with no His and no Asn is a fold, not an active site. Second, UniProt says the same thing in a CAUTION, and annotates zero Active site features on ADGB while all six reference calpains carry three each. Third, and independently of sequence analysis, MEROPS classifies androglobin as a non-peptidase homologue of family C2 and makes ADGB the holotype of that entry; the identifier block corroborates it, with the reference calpains at C02.001/.002/.004/.018/.029/.031 against ADGB at C02.972. The term additionally requires calcium dependence, for which there is no evidence of any kind on this protein - the calcium link in the literature runs through calmodulin binding at the IQ motif, which is a different thing. Reason: An InterPro domain signature has been read as an activity. The calpain fold is present but degenerate: the catalytic His and Asn are absent across six references and four alignment models, UniProt flags it in a CAUTION and annotates no active-site residues, and MEROPS independently classifies ADGB as a non-peptidase homologue with ADGB as the holotype. No experimental evidence supports calcium-dependent cysteine protease activity for ADGB in any organism. This is an electronic inference removed on biological grounds, not a curator's experimental call being second-guessed. Propagation Review Root cause: PROPAGATION BAD Failure modes: PSEUDO OR SUBACTIVITY LOSS FUNCTIONAL DIVERGENCE Sources checked: InterPro:IPR001300 · Peptidase_C2_calpain_cat (calpain catalytic domain signature) SUPPORTS SOURCE BUT NOT TARGET The signature itself is sound and ADGB genuinely matches the calpain catalytic fold - UniProt, PROSITE PS50203 and SMART CysPc all place the domain at 70-411. What fails is the InterPro2GO mapping from that fold to a catalytic activity, because ADGB is a fold-retaining pseudoenzyme that has lost the general base and the Asn. The defect is in the propagation, not in the source: this is why the root cause is PROPAGATION_BAD and not SOURCE_WEAK_OR_INFERRED, which my own analysis would contradict. Supporting Evidence: file:human/ADGB/ADGB-uniprot.txt The calpain domain lacks the conserved active site residues. file:human/ADGB/ADGB-bioinformatics/RESULTS.md A papain-fold cysteine protease cannot catalyse without the general-base histidine that deprotonates the nucleophile. A retained Cys with no His and no Asn is a fold, not an active site. file:human/ADGB/ADGB-bioinformatics/RESULTS.md All 6 reference calpains: Cysteine. ADGB: Non-peptidase homologue, and ADGB is the holotype of that entry. PMID:22115833 The calpain-like region is homologous to the catalytic domain II of the large subunit of human calpain-7.
GO:0006508 proteolysis	IEA GO_REF:0000002	MARK AS OVER ANNOTATED	Summary: Marked as over-annotated rather than removed, because two things are true at once and they pull in opposite directions. The route that produced this row is the same unsound one that produced the GO:0004198 row: InterPro2GO reading a degenerate calpain fold as a protease. On that basis alone the term would go. But there is a real, published observation that ADGB contributes to proteolysis of septin 10, and it must not be erased by a structural argument. Reading past the abstract shows exactly what was and was not shown. The assay is co-overexpression of ADGB and SEPT10 in HEK293 cells, with a dose-dependent 37 kDa SEPT10 fragment appearing in the presence of ADGB; the perturbations that reduced it were a whole-IQ-domain deletion and a whole-protease-domain deletion. There is no purified-protein cleavage assay, no protease inhibitor, and crucially no catalytic-residue point mutant - which is the experiment that would demonstrate catalysis, and for which there is no confident triad to target. The word "catalytic" does not appear in the paper, and the authors consistently write "contributes to" rather than "cleaves". A large deletion in a 1667-residue protein can abolish an activity by disrupting folding or complex assembly without the deleted region being the catalytic module. So the conclusion may well be right by a mechanism other than direct catalysis - ADGB delivering SEPT10 to another protease, for example - but it is not established for this gene by the route that produced the annotation. That is over-annotation, not error. Reason: Derived from a catalytic domain signature that MEROPS and UniProt both hold to be non-catalytic in ADGB, so the inference route is unsound. Not removed, because a real in vitro observation of ADGB-dependent SEPT10 cleavage exists; that observation rests on co-overexpression and whole-domain deletion rather than on any demonstration that ADGB itself catalyses the bond hydrolysis, so it cannot carry the term on its own either. Propagation Review Root cause: PROPAGATION BAD Failure modes: PSEUDO OR SUBACTIVITY LOSS Sources checked: InterPro:IPR001300 · Peptidase_C2_calpain_cat (calpain catalytic domain signature) SUPPORTS SOURCE BUT NOT TARGET Same signature and same failure as the GO:0004198 row: the fold match is real, the activity inference is not. Recorded separately here because the biological-process term, unlike the molecular-function term, is not contradicted by independent data - it is merely unsupported by the route that produced it. Supporting Evidence: PMID:35700329 Collectively, these in vitro data suggest a scenario in which overexpressed ADGB proteolytically contributes to cleavage of overexpressed SEPT10 in an O2-independent but CaM-dependent manner. file:human/ADGB/ADGB-uniprot.txt Interacts with septin SEPT10; contributes to in vitro file:human/ADGB/ADGB-uniprot.txt The calpain domain lacks the conserved active site residues.
GO:0019825 oxygen binding	IEA GO_REF:0000002	KEEP AS NON CORE	Summary: Kept, but as a non-core function - and the reasoning here runs opposite to the reflex. The tempting move is to remove it: ADGB is a hexacoordinate globin whose distal position is occupied, and the primary biophysical paper states outright that the extreme autoxidation rate means O2 binding is not a physiological function of the protein. Reading the term's definition rather than its label changes the answer. GO:0019825 is defined, in full, as "Binding to oxygen (O2)". It asserts nothing about transport, delivery, storage or physiological role. And the same paper that argues against a physiological role did observe an oxy complex and measure its association rate constant of about 0.8 x 10^6 M^-1 s^-1 by stopped-flow. Oxygen binding is therefore demonstrated chemistry, and the annotation is true as written. What the data do refute are the physiological oxygen terms, and GOA does not carry them: GO:0005344 oxygen carrier activity requires binding and delivering oxygen to an acceptor or a location, and GO:0019826 oxygen sensor activity requires responding to changes in oxygen level. Neither is annotated and neither should be added - the authors' clause about "the possibility of oxygen sensing" is an explicit hedge, not evidence. Two further observations reinforce keeping this non-core: the measured autoxidation rate of at least 2.6 per second is three orders of magnitude faster than neuroglobin's, and the SEPT10 cleavage assay in cells was explicitly repeated under 0.2 percent O2 with no difference, so the one cellular process linked to ADGB is oxygen-independent. Curator precedent agrees with keeping it: the two closest comparators, human neuroglobin (Q9NPG2) and cytoglobin (Q8WWM9), are also hexacoordinate globins that are not oxygen transporters, and GOA gives each of them GO:0019825 by IDA. Removing the term from ADGB while its nearest structural analogues retain it on the same kind of evidence would be inconsistent. Reason: The term means only "binding to oxygen", and that binding has been measured on the human recombinant globin domain, so the annotation is correct as written. It is not a core function because the oxy complex is only transiently observable and autoxidises three orders of magnitude faster than neuroglobin's, and the protein's measured chemistry is oriented towards nitric oxide rather than oxygen. Supporting Evidence: PMID:38725499 This remarkable autoxidation rate strongly suggests that O2 binding is not a physiological function of the protein except for the possibility of oxygen sensing. PMID:38725499 With rapid autoxidation and high nitrite reductase activity, the globin appears to be more tailored toward nitric oxide homeostasis or buffering.
GO:0020037 heme binding	IEA GO_REF:0000002	ACCEPT	Summary: Accepted as a core molecular function, and this is the half of the chimera where the domain-derived IEA turns out to be right. It is supported experimentally in human and structurally at residue level. Experimentally: the recombinant human globin domain has been expressed and purified with heme by three independent groups, showing a Soret band at 411 nm in the ferric state shifting to 423 nm on reduction with visible bands at 529 and 558 nm, an extinction coefficient determined by the hemochromogen method, and EPR characterisation. Structurally: aligning ADGB's globin domain to reviewed globins whose heme-iron ligands UniProt annotates, and requiring both residue identity and that the column land on one of ADGB's own annotated sites, the proximal F8 histidine is retained in 3 of 3 on-register references (myoglobin H94, neuroglobin H96, cytoglobin H113 all map to ADGB H824). The annotated-site condition is doing real work here rather than being decorative: sequence identity alone does not predict register, since cytoglobin at 18.0 percent is on-register for both ligands while haemoglobin beta at 20.3 percent is on-register for neither and produces a spurious distal "match" on a histidine UniProt does not annotate. One correction to UniProt belongs on this row rather than as a change to the GO term: the protein is a His/Gln hexacoordinate globin, not a bis-histidyl one. The distal E7 position is Gln792, confirmed by UniProt's own feature table, by the Swiss-Prot sequence read directly, and by three primary papers, while UniProt's FUNCTION prose still says bis-histidyl. That affects how the heme chemistry should be described, not whether heme is bound. Reason: Directly demonstrated on the human protein by three independent laboratories, and structurally well founded - the proximal heme-iron ligand is retained and is precisely the residue UniProt annotates. Core to what androglobin is. Supporting Evidence: PMID:22115833 The recombinantly expressed human globin domain exhibits an absorption spectrum characteristic of hexacoordination of the heme iron atom. PMID:39719941 These observations suggest that Gln30 in the heme distal site may coordinate to the heme iron in the ferrous state. file:human/ADGB/ADGB-bioinformatics/RESULTS.md Proximal position (ADGB H824). 3 reference columns land on it and 3 of 3 match: ADGB retains the proximal histidine. PMID:38725499 X = His for Cygb and Gln for Adgb
GO:0031514 motile cilium	IEA GO_REF:0000044	ACCEPT	Summary: Accepted. This is the Swiss-Prot subcellular-location keyword pipeline working correctly: SL-0117 is "Flagellum", whose own curated GO mapping is GO:0031514, and UniProt's SUBCELLULAR LOCATION for ADGB is "Cell projection, cilium, flagellum". Unusually for a keyword-derived row, the term is supported well beyond the sperm flagellum that motivated it, which is why the broader motile-cilium term is the right level rather than an over-reach. ADGB expression across human tissues is specifically associated with motile-ciliated cell types, its promoter is a direct target of the ciliogenic transcription factors FOXJ1 and RFX2, and overexpressing full-length ADGB increases the number of ciliated cells. In Tetrahymena, Adgb is a subunit of the C1b/C1f supercomplex of the ciliary central apparatus. A useful counterweight kept in view: deleting Adgb in Tetrahymena caused only minor changes in ciliary motility, unlike deletion of its partners Spef2A or Cfap69, so ADGB is a resident of motile cilia rather than a core motor or structural component of the projection - which is exactly what a located_in term claims and no more. Reason: Correct keyword-to-GO mapping, and independently supported in three systems - human motile-ciliated cell types with FOXJ1/RFX2 regulation, mouse sperm flagellum, and the ciliate central apparatus. Supporting Evidence: PMID:33453283 specifically being associated with cell types forming motile cilia PMID:33453283 cell culture studies indicated an ADGB-dependent increase in the number of ciliated cells upon overexpression of the full-length protein, confirming a ciliogenesis-associated role of ADGB in mammals PMID:34083607 C1b/C1f contains several evolutionarily conserved proteins: Spef2A, Cfap69, Cfap246/LRGUK, Adgb/androglobin
GO:0007283 spermatogenesis	IEA GO_REF:0000107	KEEP AS NON CORE	Summary: Correct, but kept as non-core. Ensembl Compara transfer from the 1:1 mouse ortholog, whose own annotation is an IMP from the knockout study - Adgb-null males are infertile with reduced sperm concentration and motility, abnormal spermatid elongation and increased apoptosis in the cauda epididymis. Checked for the ACTR8-style complex projection and it is absent: the supporting reference annotates only 2 distinct entities in total and its phenotype terms, GO:0007283 IMP and GO:0007286 IMP, sit on Adgb alone, the gene actually knocked out. The transfer is also corroborated directly in human rather than resting on the mouse alone: bi-allelic ADGB variants have been found in infertile men in three independent cohorts. Kept as a non-core parent of the more informative spermatid development term GO:0007286, which is what carries the process in core_functions. Reason: Ortholog transfer from a knockout-based IMP, corroborated by human patient genetics in three independent cohorts; no projection artefact. Supporting Evidence: PMID:35700329 it locates to the sperm flagellum, the annulus, and the midpiece, and that it is crucial for male fertility and sperm formation file:human/ADGB/ADGB-uniprot.txt formation and maturation of elongating spermatids, thus playing an
GO:0007286 spermatid development	IEA GO_REF:0000107	ACCEPT	Summary: Accepted. This is the same conclusion as the IBA row above, reached by a second and independent pipeline: Ensembl Compara transferring mouse Adgb's IMP from PMID:36995441. Worth recording explicitly rather than passing over, because it means GO:0007286 is annotated twice on this gene and the duplication is not additional evidence - both rows trace to the same single ortholog and the same paper. Across the whole record, 8 of the 13 GOA rows rest on two publications and one donor organism. That is not an error and I have not marked it as one, but anyone counting independent support for ADGB should know the effective N. Reason: Same well-founded ortholog transfer as the IBA row, by a different pipeline. Correct, but it is a duplicate rather than corroboration. Supporting Evidence: PMID:36995441 Spermatogenesis was also abnormal, with malformation of both elongating and elongated spermatids
GO:0036126 sperm flagellum	IEA GO_REF:0000107	ACCEPT	Summary: Accepted. The donor holds GO:0036126 by its own IDA from PMID:35700329, so the transfer lands on exactly the term the mouse data support. Human immunofluorescence independently places ADGB in the flagella of human spermatogenic cells, and the human loss-of-function phenotype - short, angled, coiled and absent tails with disrupted 9+2 axonemal structure and a disorganised mitochondrial sheath - is what a flagellar protein's loss looks like. The same human study also reports acrosomal localisation, which GOA does not capture; see suggested_questions rather than a proposed annotation here, since it rests on one study's immunofluorescence. Reason: Ortholog IDA at the identical term, independently reproduced by immunofluorescence in human spermatogenic cells. Supporting Evidence: PMID:41834962 ADGB was found to be highly expressed after puberty in both human and mouse testes and was localized to the acrosome and flagella of spermatogenic cells. PMID:35700329 it locates to the sperm flagellum, the annulus, and the midpiece, and that it is crucial for male fertility and sperm formation
GO:0097225 sperm midpiece	IEA GO_REF:0000107	ACCEPT	Summary: Accepted, and it duplicates the IBA row for the same term by a second pipeline from the same donor and paper. The donor's own evidence is an IDA at this exact term. The human ultrastructural phenotype is consistent - a disorganised mitochondrial sheath is a midpiece defect - though that is phenotype rather than localisation and does not by itself establish the component. Reason: Ortholog IDA at the identical term; duplicate of the IBA row by a second pipeline. Supporting Evidence: file:human/ADGB/ADGB-uniprot.txt along the whole sperm flagellum. Detected in the annulus of the sperm
GO:0097227 sperm annulus	IEA GO_REF:0000107	ACCEPT	Summary: Accepted, duplicating the IBA row for the same term. The donor carries an IDA at this term, and the annulus is the location with the strongest mechanistic support: ADGB and SEPT10 co-localise there in stage-15 spermatids and mature sperm, and SEPT10 mislocalises when Adgb is lost. Septins are the structural constituents of the sperm annulus, so an ADGB-septin interaction at that site coheres with everything else known about the gene. Reason: Ortholog IDA at the identical term, with an interaction partner and a loss-of-function mislocalisation phenotype both anchored at this same structure. Supporting Evidence: file:human/ADGB/ADGB-uniprot.txt along the whole sperm flagellum. Detected in the annulus of the sperm PMID:35700329 Finally, in vitro data suggest that Adgb contributes to Sept10 proteolysis in a CaM-dependent manner.
GO:0005516 calmodulin binding	IPI PMID:36995441 ADGB variants cause asthenozoospermia and male infertility.	NEW	Summary: Proposed new annotation, and the clearest gap in this gene's record: GOA carries no calmodulin-binding annotation for ADGB in either human or mouse, despite calmodulin being the one partner that binds a defined, named motif in the protein and the one whose disruption is directly tied to human disease. UniProt annotates an IQ calmodulin-binding motif at residues 906-935, sitting between the two halves of the circularly permuted globin domain - an arrangement that is the structural signature of the whole protein family. Four independent lines support the interaction. In human patients, ADGB variants causing asthenozoospermia disrupt binding of ADGB to calmodulin, and UniProt records this with ECO:0000269 against the human entry. In cells, a truncated construct covering the globin and IQ domains co-immunoprecipitates calmodulin robustly, and mass spectrometry of the isolated globin-domain pulldown shows prominent enrichment of endogenous calmodulin. Biophysically, fluorescein-labelled calmodulin mutants show a 35 percent quenching with the N-lobe label against 10 percent with the C-lobe label on adding the purified ADGB globin domain, consistent with energy transfer to the heme. Functionally, calmodulin binding raises the domain's nitrite reductase catalytic efficiency roughly two-fold, and deleting the IQ motif abolishes that activation. Recorded as IPI against the human patient-variant study, with calmodulin-1 as the supporting entity. Note the one negative in the record, kept in view rather than suppressed: co-immunoprecipitation of full-length ADGB did not detect calmodulin under basal conditions in HEK293 cells, which the authors attribute to interference from the long C-terminal region. That argues the interaction is regulated or conformationally gated, not that it is absent. Reason: Fills the most conspicuous molecular-function gap in the record. ADGB has a UniProt-annotated IQ motif, human disease variants that disrupt calmodulin binding, direct co-immunoprecipitation and mass-spectrometric evidence, biophysical binding data on the purified human domain, and a measured functional consequence - yet no GO annotation in either species. Supporting Evidence: PMID:36995441 The variants disrupted the binding of ADGB to calmodulin. PMID:35700329 a truncated construct covering the globin and IQ domains displayed robust ADGB-CaM interaction PMID:39719941 The circularly permutated globin domain of Adgb was well folded with a heme group, which can interact with CaM via the IQ motif.
GO:0070026 nitric oxide binding	IDA PMID:38725499 The circularly permuted globin domain of androglobin exhibit...	NEW	Summary: Proposed new annotation. The purified human androglobin globin domain binds nitric oxide, and does so in a way that is unusual enough to be diagnostic rather than generic globin chemistry: the complex is five-coordinate, which in the globin superfamily is highly atypical and is instead the signature of hemoproteins with nitric-oxide storage or sensing roles such as soluble guanylate cyclase and cytochrome c prime. The characterisation used optical spectroscopy, EPR, stopped-flow and femtosecond laser flash photolysis; the NO-bound Soret peak is blue-shifted to 395 nm against the 420-430 nm typical of hexacoordinate ferrous-NO globins, and the measured affinity is in the 10^-10 to 10^-11 M range. Adding NO to the ferric protein produced no optical change, so the binding is specific to the ferrous state rather than a general heme artefact. The term is well precedented for this chemistry. GOA annotates GUCY1B1 to GO:0070026 by IEA - the code is stated because the neighbouring holders are experimental and it must not be read across - and soluble guanylate cyclase is precisely the five-coordinate NO hemoprotein the authors name as ADGB's comparator, alongside cytochrome c prime. The experimental precedent comes from CBS, THAP4 (nitrobindin) and the haemoglobin complex CPX-2158, which hold the term by IDA. This is a molecular function of ADGB that GOA does not record at all, and unlike the oxygen term it is the activity the biophysics actually points to. Stated caveat: the measurements are on the isolated recombinant globin domain, not full-length androglobin, and no in vivo NO-related phenotype has been demonstrated for ADGB in any organism. Reason: Direct, multi-method biophysical demonstration on the purified human globin domain of an atypical five-coordinate NO complex with sub-nanomolar affinity. Not represented anywhere in GOA for this gene. Supporting Evidence: PMID:38725499 Adgb binds NO as a five-coordinate heme iron PMID:38725499 With rapid autoxidation and high nitrite reductase activity, the globin appears to be more tailored toward nitric oxide homeostasis or buffering.
GO:0098809 nitrite reductase activity	IDA PMID:38725499 The circularly permuted globin domain of androglobin exhibit...	NEW	Summary: Proposed new annotation. Two independent laboratories have measured nitrite reductase activity on the purified human androglobin globin domain, and a third study has probed it by mutagenesis. The ferrous heme reacts with nitrite to generate nitric oxide, followed spectroscopically as loss of the 423 nm Soret with a rise near 386 nm; the kinetics fit Michaelis-Menten, giving kcat/KM of 0.046 mM^-1 s^-1 for the domain alone rising to 0.102 on calmodulin binding, and mutating the distal glutamine to tyrosine further enhances the activity. The activity is also modulated by the redox state of the CD-loop disulfide. Term choice was checked against the definitions rather than the labels. GO:0050421 "nitrite reductase (NO-forming) activity" was considered and rejected: its definition is cytochrome-c-specific, describing the cd1-type enzyme, and does not describe a deoxyferrous globin reducing nitrite. GO:0098809 is the correct level, and that is confirmed by curator practice rather than only by reading the definitions: GOA already annotates human neuroglobin, cytoglobin and myoglobin to GO:0098809 by IDA for exactly this chemistry, and none of the three uses the GO:0050421 child. Stated caveats, which are the authors' own. All measurements are on the isolated recombinant globin domain rather than full-length androglobin, they use dithionite as the reductant, and the KM values are in the millimolar range - well above physiological nitrite. The original authors write that it remains unclear whether this is a natural function of Adgb. It is proposed here as a demonstrated in vitro activity, not as an established physiological role, and it is not listed among the core functions for that reason. Reason: Replicated in vitro catalytic activity on the human protein's globin domain, measured by two independent groups with full Michaelis-Menten kinetics and probed by mutagenesis by a third. Absent from GOA. Proposed with the isolated-domain and millimolar-KM caveats explicit. Supporting Evidence: PMID:38725499 With rapid autoxidation and high nitrite reductase activity, the globin appears to be more tailored toward nitric oxide homeostasis or buffering. PMID:39719941 the binding of CaM enhanced the nitrite reductase activity of Adgb PMID:39719941 it remains unclear whether this is a natural function of Adgb

Core Functions

Heme-binding circularly permuted globin domain that coordinates a b-type heme through a retained proximal histidine (His824), with a glutamine rather than the canonical histidine at the distal position (Gln792). The resulting His/Gln hexacoordinate heme binds nitric oxide as an atypical five-coordinate complex and reduces nitrite to nitric oxide, while binding oxygen only transiently. This is the module that defines androglobin as a globin.

Molecular Function:

heme binding

Cellular Locations:

sperm flagellum

Supporting Evidence:

PMID:22115833
The recombinantly expressed human globin domain exhibits an absorption spectrum characteristic of hexacoordination of the heme iron atom.
file:human/ADGB/ADGB-bioinformatics/RESULTS.md
Verdict: the globin domain is intact as a heme protein, but it is a His/Gln hexacoordinate globin, not a bis-histidyl one.
PMID:38725499
X = His for Cygb and Gln for Adgb

Calcium-sensor coupling through an IQ motif that lies between the two halves of the split globin domain. Calmodulin binding places its N-lobe adjacent to the heme pocket and increases the domain's nitrite reductase efficiency about two-fold; deleting the IQ motif abolishes that activation. In human patients, variants that disrupt calmodulin binding cause asthenozoospermia, making this the molecular function most directly tied to disease.

Molecular Function:

calmodulin binding

Cellular Locations:

sperm annulus

Supporting Evidence:

PMID:36995441
The variants disrupted the binding of ADGB to calmodulin.
PMID:39719941
the binding of CaM enhanced the nitrite reductase activity of Adgb
PMID:35700329
a truncated construct covering the globin and IQ domains displayed robust ADGB-CaM interaction

Required for the late, post-meiotic remodelling of spermatids into functional spermatozoa. Androglobin localises to the flagellum, midpiece and annulus of elongating spermatids and binds septin 10, CFAP69, SPEF2, TTC29 and CFAP47; its loss in mice causes infertility with abnormal head shaping and defective manchette, annulus and flagellum organisation, and bi-allelic human variants cause asthenozoospermia and oligoasthenoteratozoospermia. The molecular activity underlying this requirement is not established - notably, the calpain-like region is a non-catalytic pseudoprotease - so this is recorded as a cellular role rather than as a molecular function.

Directly Involved In:

spermatid development

Cellular Locations:

sperm midpiece sperm annulus motile cilium

Supporting Evidence:

PMID:35700329
it locates to the sperm flagellum, the annulus, and the midpiece, and that it is crucial for male fertility and sperm formation
PMID:38385883
the spermatozoa from patients harboring ADGB variants showed multiple acrosome and flagellum malformations under light and electron microscopy
PMID:41834962
Co-immunoprecipitation experiments confirmed TTC29 and CFAP47 as interacting proteins of ADGB.

Nitric oxide handling at the same heme. The ferrous globin domain binds nitric oxide as a five-coordinate complex with sub-nanomolar affinity - unusual in the globin superfamily, and characteristic instead of NO-storage or NO-sensing hemoproteins such as soluble guanylate cyclase. The same heme also reduces nitrite to nitric oxide in the isolated globin domain, at millimolar K_M and so of untested physiological significance, an activity that calmodulin binding at the IQ motif enhances about two-fold. Recorded as a core function because it is what the heme measurably does, whereas heme binding records only that the cofactor is present; the nitric oxide binding is the better-founded half of that chemistry, at sub-nanomolar affinity. The qualifier is stated rather than buried: every measurement is on the isolated recombinant globin domain, and no nitric-oxide-dependent phenotype has been demonstrated for androglobin in any organism.

Molecular Function:

nitric oxide binding

Cellular Locations:

sperm flagellum

Supporting Evidence:

PMID:38725499
Adgb binds NO as a five-coordinate heme iron
PMID:38725499
With rapid autoxidation and high nitrite reductase activity, the globin appears to be more tailored toward nitric oxide homeostasis or buffering.
PMID:39719941
the binding of CaM enhanced the nitrite reductase activity of Adgb

References

GO_REF:0000002

Gene Ontology annotation through association of InterPro records with GO terms

GO_REF:0000033

Annotation inferences using phylogenetic trees

GO_REF:0000044

Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping, accompanied by conservative changes to GO terms applied by UniProt

GO_REF:0000107

Automatic transfer of experimentally verified manual GO annotation data to orthologs using Ensembl Compara

PMID:22115833

Androglobin: a chimeric globin in metazoans that is preferentially expressed in Mammalian testes.

The human androglobin globin domain was recombinantly expressed and shows an absorption spectrum characteristic of hexacoordinate heme iron, establishing heme binding for the human protein directly rather than by inference from the family.

"The recombinantly expressed human globin domain exhibits an absorption spectrum characteristic of hexacoordination of the heme iron atom."
The N-terminal region is homologous to the catalytic domain II of human calpain-7, which is the origin of the InterPro IPR001300 match and hence of the two proteolysis-related IEA rows.

"The calpain-like region is homologous to the catalytic domain II of the large subunit of human calpain-7."
The globin domain is a genuine myoglobin-like fold that has been rearranged and split, which is why the two halves receive separate UniProt Domain features.

"The globin domain satisfies the criteria of a myoglobin-like fold but is rearranged and split into two parts."

PMID:38725499

The circularly permuted globin domain of androglobin exhibits atypical heme stabilization and nitric oxide interaction.

Oxygen binding by the androglobin globin domain is demonstrable but transient, and the authors conclude from the autoxidation rate that it is not a physiological function. This is the evidence behind keeping GO:0019825 as non-core and behind not proposing GO:0005344 oxygen carrier activity or GO:0019826 oxygen sensor activity.

"This remarkable autoxidation rate strongly suggests that O2 binding is not a physiological function of the protein except for the possibility of oxygen sensing."
The measured chemistry points to nitric oxide handling rather than oxygen, which is the basis for the two proposed NEW molecular-function annotations.

"With rapid autoxidation and high nitrite reductase activity, the globin appears to be more tailored toward nitric oxide homeostasis or buffering."
Androglobin binds nitric oxide as a five-coordinate complex, which is highly unusual among globins and characteristic of nitric-oxide storage hemoproteins.

"Adgb binds NO as a five-coordinate heme iron"
The distal heme-iron ligand of androglobin is a glutamine, not a histidine, stated explicitly in contrast with cytoglobin. This contradicts UniProt's bis-histidyl FUNCTION text and agrees with UniProt's own feature table.

"X = His for Cygb and Gln for Adgb"
A tyrosine replaces the otherwise invariant CD1 phenylalanine, a further departure from canonical eukaryotic globin architecture that affects heme stabilisation.

"Exceptional for eukaryotic globins is that a tyrosine takes the place of the highly conserved phenylalanine in the CD1 position, a critical point in stabilizing the heme."

PMID:39719941

Calmodulin interacts with androglobin and regulates the nitrite reductase activity.

Calmodulin binding at the IQ motif increases the nitrite reductase catalytic efficiency of the androglobin globin domain roughly two-fold, linking the calcium-sensor module directly to the heme chemistry.

"the binding of CaM enhanced the nitrite reductase activity of Adgb"
Independent confirmation that the distal heme ligand is a glutamine and the proximal ligand a histidine, in a construct whose numbering maps onto UniProt Q792 and H824.

"These observations suggest that Gln30 in the heme distal site may coordinate to the heme iron in the ferrous state."
The circularly permuted globin domain folds correctly with heme and engages calmodulin through the IQ motif, supporting both the heme-binding and the proposed calmodulin-binding annotations.

"The circularly permutated globin domain of Adgb was well folded with a heme group, which can interact with CaM via the IQ motif."
The authors themselves qualify whether nitrite reduction is a natural function of androglobin, which is recorded as an explicit caveat on the proposed GO:0098809 annotation.

"it remains unclear whether this is a natural function of Adgb"

PMID:42372363

Spectroscopic studies on human androglobin regulated by its heme distal Gln12 and IQ motif via interaction with calmodulin.

A third independent confirmation that the heme distal residue of human androglobin is a glutamine, here established by mutagenesis rather than by inference - the authors generate Q12H and Q12Y substitutions and show that the distal residue controls both stability and nitrite reductase activity, and that deleting the IQ motif abolishes calmodulin-mediated activation.

"investigated the role of its heme distal residue Gln12 through the generation of Q12H and Q12Y mutants"

PMID:35700329

Androglobin, a chimeric mammalian globin, is required for male fertility.

Adgb-null mice are infertile and androglobin localises to the sperm flagellum, annulus and midpiece. This is the source of the mouse IDA annotations that both the PAINT IBA rows and the Ensembl Compara rows on human ADGB are transferred from.

"it locates to the sperm flagellum, the annulus, and the midpiece, and that it is crucial for male fertility and sperm formation"
The proteolysis claim is stated by the authors as a suggestion from in vitro data about overexpressed proteins, not as a demonstration that androglobin catalyses the cleavage. This is the wording the MARK_AS_OVER_ANNOTATED call on GO:0006508 rests on.

"Collectively, these in vitro data suggest a scenario in which overexpressed ADGB proteolytically contributes to cleavage of overexpressed SEPT10 in an O2-independent but CaM-dependent manner."
A construct spanning the globin and IQ domains binds calmodulin robustly by co-immunoprecipitation, whereas full-length androglobin did not under basal conditions, suggesting the interaction is conformationally gated by the long C-terminal region.

"a truncated construct covering the globin and IQ domains displayed robust ADGB-CaM interaction"

PMID:36995441

ADGB variants cause asthenozoospermia and male infertility.

Human ADGB variants causing asthenozoospermia disrupt binding of androglobin to calmodulin. This is the human-specific evidence behind the proposed GO:0005516 annotation, and UniProt records the same interaction with ECO:0000269 against the human entry.

"The variants disrupted the binding of ADGB to calmodulin."
CFAP69 and SPEF2 were confirmed as androglobin-binding proteins, connecting androglobin to the ciliary and flagellar assembly machinery.

"In particular, CFAP69 and SPEF2 were confirmed to bind to ADGB."
Adgb-null mice show abnormal spermatogenesis with malformation of elongating and elongated spermatids, the IMP that both the GO:0007286 IBA and Compara rows derive from.

"Spermatogenesis was also abnormal, with malformation of both elongating and elongated spermatids"

PMID:38385883

Whole-exome sequencing identifies ADGB as a novel causative gene for male infertility in humans: from motility to fertilization.

Bi-allelic ADGB variants in three unrelated Han Chinese men cause severe asthenoteratozoospermia with acrosome and flagellum malformations on light and electron microscopy, providing human loss-of-function corroboration for the spermatogenesis and flagellum annotations transferred from mouse.

"the spermatozoa from patients harboring ADGB variants showed multiple acrosome and flagellum malformations under light and electron microscopy"

PMID:41834962

[Whole Exome Sequencing Identified Novel Pathogenic Mutations of ADGB in Patients With Oligoasthenozoospermia].

Immunofluorescence places androglobin in the acrosome and flagella of human and mouse spermatogenic cells, with expression rising after puberty. The flagellar localisation corroborates the transferred GO:0036126 annotation directly in human; the acrosomal localisation is not currently captured by GOA and is raised as a question rather than proposed, since it rests on this single study.

"ADGB was found to be highly expressed after puberty in both human and mouse testes and was localized to the acrosome and flagella of spermatogenic cells."
TTC29 and CFAP47 were confirmed as androglobin interactors by co-immunoprecipitation, extending the set of ciliary and flagellar partners beyond septin 10, CFAP69 and SPEF2.

"Co-immunoprecipitation experiments confirmed TTC29 and CFAP47 as interacting proteins of ADGB."

PMID:34083607

Composition and function of the C1b/C1f region in the ciliary central apparatus.

Androglobin is a component of the C1b/C1f supercomplex of the ciliary central apparatus in Tetrahymena, alongside Spef2A and Cfap69 - the same proteins that were later found to bind androglobin in mammals. This supports the motile-cilium localisation outside the sperm context.

"C1b/C1f contains several evolutionarily conserved proteins: Spef2A, Cfap69, Cfap246/LRGUK, Adgb/androglobin"
Deleting Adgb caused only minor changes in ciliary motility, unlike deletion of Spef2A or Cfap69 which abolished the entire C1b projection. Androglobin is therefore a resident of the structure rather than a core structural or motor component, which is consistent with annotating localisation but not a motility function.

"Loss of either Cfap246 or Adgb caused only minor alterations in ciliary motility."

PMID:33453283

Androglobin gene expression patterns and FOXJ1-dependent regulation indicate its functional association with ciliogenesis.

Across human tissues, ADGB expression is specifically associated with motile-ciliated cell types beyond the testis, including the female reproductive tract, lung and brain, supporting the motile-cilium annotation as more than a sperm-flagellum artefact.

"specifically being associated with cell types forming motile cilia"
Overexpressing full-length ADGB increases the number of ciliated cells, and the ADGB promoter is a direct target of the ciliogenic transcription factors FOXJ1 and RFX2.

"cell culture studies indicated an ADGB-dependent increase in the number of ciliated cells upon overexpression of the full-length protein, confirming a ciliogenesis-associated role of ADGB in mammals"

PMID:37158461

Congenital heart defects caused by FOXJ1.

PMID:41138754

Expression analysis of androglobin and its influence on the transcriptome in cancer.

Suggested Experiments

Experiment: Express and purify the isolated ADGB calpain-like region (residues 70-411) and full-length androglobin, and assay them directly against recombinant SEPT10 in the presence and absence of calcium and calmodulin. Include a C132S substitution as the catalytic-residue control - the point mutant that the existing cell-based work never made - and a panel of class-specific protease inhibitors. In parallel, repeat the HEK293 co-overexpression experiment with the C132S full-length protein: if the 37 kDa SEPT10 band still appears, androglobin is not the catalyst, and the whole-domain deletion result reflects loss of a binding or scaffolding function rather than of catalysis.

Hypothesis: Androglobin does not itself hydrolyse peptide bonds; the SEPT10 fragment observed on co-overexpression is produced by a cellular protease that androglobin recruits or licenses in a calmodulin-dependent manner.

Type: in vitro reconstitution and structure-function

Experiment: Measure oxygen association and dissociation kinetics and the autoxidation rate on full-length androglobin, and on the globin domain in complex with calcium-loaded calmodulin, by stopped-flow and flash photolysis, comparing directly against the published isolated-domain values. Repeat with the Q792H variant, which restores the canonical distal histidine and has already been shown to improve stability, to test whether the distal glutamine is what destabilises the oxy complex.

Hypothesis: The extreme autoxidation rate measured for the isolated globin domain is a property of the truncated construct, and the full-length protein or the calmodulin-bound complex stabilises the oxy form enough for oxygen chemistry to be physiologically accessible.

Type: biophysical kinetics

Experiment: Generate Adgb knock-in mice carrying the Q792H equivalent (restoring the ancestral distal histidine) and, separately, a proximal H824A heme-binding-null allele, and compare sperm counts, motility, annulus and manchette organisation and axonemal ultrastructure against wild-type and full knockout. A heme-null allele that phenocopies the knockout would establish that the globin chemistry, not merely the protein's presence, is what spermatid development requires; a heme-null allele with a normal phenotype would show the reverse and would reframe androglobin as a cytoskeletal adaptor that happens to carry a heme.

Hypothesis: The distal glutamine is functionally required in vivo, and androglobin's role in spermatid maturation depends on its heme chemistry rather than only on its scaffolding interactions.

Type: mouse genetics

Experiment: Quantify nitric oxide output in wild-type versus Adgb-null spermatids using a cell-permeant NO probe under controlled oxygen tensions spanning the testicular range, with and without nitrite supplementation, and confirm by measuring downstream nitrosation. Complement with quantitative proteomics of S-nitrosylated targets in wild-type versus knockout testis to identify whether any of the known androglobin partners - septin 10, CFAP69, SPEF2, TTC29, CFAP47 - are among them, which would connect the heme chemistry to the cytoskeletal phenotype.

Hypothesis: Androglobin generates nitric oxide from nitrite in post-meiotic germ cells under the low oxygen tension of the testis.

Type: cell biology and redox proteomics

Deep Research

Affinage

(ADGB-deep-research-affinage.md)

Affinage mechanistic annotation for ADGB (human) Affinage Affinage (Claude Sonnet reading pass + Opus synthesis pass) 9 citations

Affinage mechanistic annotation for ADGB (human)

Current model (mechanistic narrative)

Androglobin (ADGB) is a chimeric metazoan protein that functions in the assembly of motile cilia/flagella and in spermatid maturation [PMID:35700329, PMID:34083607]. Its unique modular architecture combines an N-terminal calpain-like catalytic domain, a circularly permuted hexacoordinated globin domain, and an IQ calmodulin-binding motif PMID:22115833. Calmodulin binds the IQ motif and enhances the nitrite reductase activity of the heme-binding globin domain PMID:39719941, and ADGB is in turn required for proper calmodulin localization or stability in sperm PMID:38385883. In spermatogenesis, ADGB localizes to the acrosome and flagella PMID:41834962 and is required for sperm head shaping, manchette and annulus formation, and flagellum integrity, acting through interactions with cytoskeletal and ciliary assembly factors including septin 10, CFAP69, SPEF2, TTC29, and CFAP47 [PMID:35700329, PMID:36995441, PMID:41834962]; loss of ADGB drives mislocalization of Sept10 and contributes to its proteolysis in a calmodulin-dependent manner PMID:35700329. In the ciliary central apparatus of Tetrahymena, ADGB associates with the C1b/C1f supercomplex PMID:34083607. ADGB expression is transcriptionally controlled by the ciliogenic regulators FOXJ1 and RFX3 [PMID:37158461, PMID:41138754]. Bi-allelic pathogenic ADGB variants cause male infertility presenting as asthenozoospermia and oligoasthenoteratozoospermia with acrosome, mitochondrial sheath, and axonemal defects [PMID:36995441, PMID:38385883, PMID:41834962].

Affinage mechanism profile (its own GO/Reactome grounding)

Recorded for reference. The AIGR evaluation found this grounding is coarse (collapses to general parents) and can contradict the narrative — do not import these GO ids directly; re-ground from the narrative + PMIDs.

molecular_activity: GO:0140096 catalytic activity, acting on a protein, GO:0016491 oxidoreductase activity, GO:0008092 cytoskeletal protein binding
localization: GO:0005929 cilium, GO:0005856 cytoskeleton
pathway (Reactome): R-HSA-1474165 Reproduction, R-HSA-1852241 Organelle biogenesis and maintenance
partners: SEPT10, CFAP69, SPEF2, TTC29, CFAP47, CALM1
complexes: C1b/C1f ciliary central apparatus supercomplex

Dated findings (citation-anchored)

Year	Confidence	Finding	PMIDs	Journal
2011	Medium	Androglobin (ADGB) is a chimeric protein with a unique modular architecture comprising an N-terminal calpain-like domain homologous to catalytic domain II of human calpain-7, an internal circularly permuted globin domain, and an IQ calmodulin-binding motif. The recombinantly expressed human globin domain exhibits an absorption spectrum characteristic of hexacoordination of the heme iron atom.	PMID:22115833	Molecular biology and evolution
2022	High	Adgb knockout mice display male infertility with impaired spermatid maturation, abnormal sperm shape, and ultrastructural defects in microtubule and mitochondrial organization. Immunoprecipitation and mass spectrometry identified septin 10 (Sept10) as an interactor of Adgb, confirmed by reciprocal co-immunoprecipitation both in vivo (testis lysates) and in vitro. Absence of Adgb leads to mislocalization of Sept10 in sperm, indicating defective manchette and sperm annulus formation. In vitro data suggest Adgb contributes to Sept10 proteolysis in a calmodulin-dependent manner.	PMID:35700329	eLife
2021	Medium	In Tetrahymena thermophila, Adgb/androglobin localizes to the C1b/C1f supercomplex of the ciliary central apparatus. Deletion of Adgb caused only minor alterations in ciliary motility, whereas loss of other C1b/C1f subunits (Spef2A or Cfap69) caused loss of the entire C1b projection and abnormal cilia motion.	PMID:34083607	Scientific reports
2023	Medium	Pathogenic variants in ADGB disrupt binding of ADGB to calmodulin, causing asthenozoospermia and male infertility. Mass spectrometry identified 42 candidate interacting proteins involved in sperm assembly, flagella formation, and sperm motility; CFAP69 and SPEF2 were confirmed to bind ADGB by co-immunoprecipitation.	PMID:36995441	Human genetics
2023	Medium	FOXJ1 activates the ADGB promoter in transactivation assays in vitro, establishing ADGB as a downstream transcriptional target of FOXJ1 in ciliated cells. A truncating FOXJ1 variant (p.Glu267Glyfs*12) failed to activate the ADGB promoter.	PMID:37158461	Human molecular genetics
2024	Medium	Calmodulin (CaM) interacts with ADGB via its IQ motif, and this interaction enhances the nitrite reductase activity of the ADGB heme-binding globin domain. Fluorescence quenching experiments using CaM mutants labeled at Cys41 (N-lobe) showed greater energy transfer to the heme group upon ADGB binding, consistent with predicted structural models of the Adgb-CaM complex.	PMID:39719941	RSC chemical biology
2024	Medium	Bi-allelic deleterious ADGB variants in infertile men cause multiple acrosome and flagellum malformations in spermatozoa. Functional assays revealed structural defects associated with dysregulation of ADGB and multiple spermatogenesis proteins. CaM deficiency (but normal PLCζ) was detected in sperm from ADGB-deficient patients, suggesting ADGB is required for calmodulin localization or stability in sperm.	PMID:38385883	Andrology
2025	Medium	RFX3 regulates ADGB promoter-driven luciferase activity and endogenous ADGB expression levels, identifying RFX3 as a transcriptional regulator of ADGB. Stable ADGB overexpression in A549 lung cancer cells caused transcriptomic changes indicative of increased cell motility and extracellular matrix remodeling.	PMID:41138754	Gene
2026	Medium	ADGB localizes to the acrosome and flagella of spermatogenic cells in humans and mice, with high expression after puberty. Co-immunoprecipitation experiments confirmed TTC29 and CFAP47 as interacting proteins of ADGB. Compound heterozygous pathogenic ADGB mutations cause oligoasthenoteratozoospermia with acrosome loss, disorganized mitochondrial sheath, and disrupted axonemal '9+2' microtubule structure.	PMID:41834962	Sichuan da xue xue bao. Yi xue ban

Citations

PMID:22115833
PMID:34083607
PMID:35700329
PMID:36995441
PMID:37158461
PMID:38385883
PMID:39719941
PMID:41138754
PMID:41834962

📚 Additional Documentation

Notes

(ADGB-notes.md)

ADGB (androglobin, Q8N7X0) — review notes

Accession verified two ways before starting: projects/paint/human-no-IBA-simple.csv:6472
gives human,Q8N7X0,ADGB, and UniProt returns Q8N7X0 / ADGB_HUMAN / Androglobin / 1667 aa / reviewed. The four unreviewed human ADGB entries (A0A7P0T963 1667 aa, E5RGD1 220 aa,
E5RIM8 35 aa, H0YC38 71 aa) are TrEMBL fragments and are not used anywhere.

GOA / stub reconciliation (done first, before reviewing)

wc -l  ADGB-goa.tsv          -> 14  (13 data rows + header)
tail -n +2 ... | sort -u | wc -> 13  distinct
grep -c '^- term:' stub      -> 13

13 = 13 = 13. No collapse, no duplicate TSV lines. Every GOA row has its own entry. The
GOAValidator.seed_missing_annotations key (GO ID, evidence_type, reference, negated, qualifier) happens to be unique across this gene's rows, so the known under-seeding defect
does not bite here. Nothing was restored; nothing was merged.

The 13 rows come from exactly four pipelines and, ultimately, from one donor organism:

pipeline	reference	rows
PAINT phylogenetic (IBA)	GO_REF:0000033	3
InterPro2GO (IEA)	GO_REF:0000002	4
Swiss-Prot SubCell (IEA)	GO_REF:0000044	1
Ensembl Compara ortholog transfer (IEA/ECO:0000265)	GO_REF:0000107	5

There is not one experimental annotation on human ADGB. Given PE 1: Evidence at protein level and a decade of published human biochemistry, that is an annotation gap, not an
absence of data — see "The real gap" below.

Architecture: what the two domains actually are

UniProt annotates, on the 1667-aa chain: a Calpain catalytic domain 70–411, a globin
domain split in two by circular permutation (C-terminal part 763–890, N-terminal part
936–968) with an IQ calmodulin-binding motif 906–935 between the halves, and a
coiled coil at 1588–1629. Heme-iron ligands are annotated at Q792 (distal) and
H824 (proximal).

PMID:22115833 and PMID:22115833

This is the setup for two opposite errors, and I tested both rather than assuming either.
They came out asymmetric: the calpain half fails, the globin half survives.

Test 1 — is the calpain domain a protease? No.

Reproducible analysis: ADGB-bioinformatics/adgb_sites.py, results in
ADGB-bioinformatics/RESULTS.md (regenerated by the script; a fresh run byte-matches the
committed file).

Method: align each of six reviewed reference calpains' catalytic domains to ADGB 70–411
under four substitution/gap models, and read the ADGB residue in each column anchored on
the reference's own UniProt Active site feature. Per-residue, not per-triad — a single
model's triad count is an alignment artefact at these identities (18–29%).

Nucleophile Cys: retained. 11 of 15 aligned columns have a Cys in ADGB, and it is
always the same residue, C132. Which references reach it varies by model; the ADGB
position does not.
General-base His: lost.
[file:human/ADGB/ADGB-bioinformatics/RESULTS.md "| general base His | 22 | [267, 320, 321, 326, 332, 334, 352] | 1/22 ['H267'] |"]
The single hit appears under one model only, at a position no other model selects.
Asn: lost.
[file:human/ADGB/ADGB-bioinformatics/RESULTS.md "| Asn | 22 | [319, 343, 344, 346, 353, 357] | 0/22 (none) |"]

[file:human/ADGB/ADGB-bioinformatics/RESULTS.md "A papain-fold cysteine protease cannot catalyse without the general-base histidine that deprotonates the nucleophile. A retained Cys with no His and no Asn is a fold, not an active site."]

Caveat I must state rather than hide: ADGB carries zero UniProt Active site
features, so the lands_on_subject_annotated_site condition (the load-bearing second
condition from the AADACL2 rule) is vacuous in this half of the analysis and its all-"no"
column is not a measurement. That absence is itself the signal: UniProt annotates the
Calpain catalytic domain on ADGB but propagates no catalytic residues into it, while all six
reference calpains carry three each. The condition is live in Test 2.

Two independent lines agree, neither of which depends on my alignment:

UniProt's own CAUTION:
[file:human/ADGB/ADGB-uniprot.txt "The calpain domain lacks the conserved active site residues."]
(ECO:0000305|PubMed:22115833), while the SIMILARITY line still places it
[file:human/ADGB/ADGB-uniprot.txt "In the N-terminal section; belongs to the peptidase C2"] family.
MEROPS classifies ADGB as a non-peptidase homologue, with ADGB as the holotype.
[file:human/ADGB/ADGB-bioinformatics/RESULTS.md "All 6 reference calpains: Cysteine. ADGB: Non-peptidase homologue, and ADGB is the holotype of that entry."]
The identifier block corroborates it: reference calpains are C02.001/.002/.004/.018/.029/.031,
ADGB is C02.972. I did not assume the MEROPS numbering convention — the suffixes are
derived in the script and the catalytic type is read from the MEROPS record itself.

So GO:0004198 calcium-dependent cysteine-type endopeptidase activity (IEA from
InterPro:IPR001300) is domain-name-propagated-into-activity, and it is a REMOVE that
has been earned rather than asserted.

But the mirror error is also live here — ADGB is implicated in proteolysis

PMID:35700329
and UniProt records
[file:human/ADGB/ADGB-uniprot.txt "Interacts with septin SEPT10; contributes to in vitro"]
[file:human/ADGB/ADGB-uniprot.txt "proteolytic cleavage of SEPT10 in a calmodulin-dependent manner."]

Read past the abstract, though, and the authors are careful about exactly what was shown:
PMID:35700329

The assay is co-overexpression of both proteins in HEK293 cells. The perturbations were a
whole-IQ deletion and a whole-protease-domain deletion — not a catalytic-residue point
mutant, which is what would demonstrate catalysis, and which there is no confident triad to
build. No purified-protein cleavage assay, no protease inhibitor. The word "catalytic" does
not occur in the paper.

That is why GO:0006508 proteolysis is MARK_AS_OVER_ANNOTATED and not REMOVE: the route
that produced it (a catalytic signature ADGB does not fulfil) is unsound, but the conclusion
is not refuted, and it may yet be right by a different mechanism — ADGB targeting SEPT10 to a
different protease, for instance.

Test 2 — is the globin domain a real heme protein? Yes. Is it bis-histidyl? No.

Here ADGB does have its own annotated sites, so the annotated-site condition discriminates.

Proximal (ADGB H824): retained.
[file:human/ADGB/ADGB-bioinformatics/RESULTS.md "Proximal position (ADGB H824). 3 reference columns land on it and 3 of 3 match: ADGB retains the proximal histidine."]
(myoglobin H94, neuroglobin H96, cytoglobin H113.)
Distal (ADGB Q792): it is a glutamine.
[file:human/ADGB/ADGB-bioinformatics/RESULTS.md "5 reference columns land on it, from 4 distinct globins, and the reference
residue is H in every one. ADGB has Q."]

Sequence identity does not predict alignment register here — CYGB at 18.0% is on-register for
both sites while HBB at 20.3% is on-register for neither, and HBB's apparent "distal His
match" (H830) lands on a histidine UniProt does not annotate. The annotated-site condition is
what separates them; residue identity alone would have manufactured a false conservation call.

Three primary papers agree, and the register arithmetic checks out

Each paper numbers its own construct differently, so I pinned the register rather than
trusting the labels. Nie et al. report His62 proximal and residue 30 distal; UniProt
reports H824 and Q792. 824 − 792 = 32 = 62 − 30. Their construct therefore begins at
UniProt 763 — which is exactly the start of UniProt's annotated Globin; C-terminal part
domain — and their Cys3/Cys25 disulfide maps to real cysteines C765/C787. The mapping is
independently consistent at four positions.

PMID:38725499, and their alignment key labels the
position PMID:38725499.
PMID:39719941 (Fig. 1B legend), concluding
PMID:39719941
PMID:42372363
— the distal Gln is in this paper's title and is mutated experimentally.

Note a trap inside PMID:39719941: its Results body text says "Asn30 in helix E is
located in the heme distal position", while the figure legend of the same figure and the
concluding sentence of the same paragraph both say Gln30. The sequence settles it — UniProt
position 792 is a Gln, read directly from the Swiss-Prot sequence. Quoting the body sentence
alone would have propagated a typo.

The UniProt entry contradicts itself, and this is worth reporting upstream

The FUNCTION line says ADGB is a
[file:human/ADGB/ADGB-uniprot.txt "Probable chimeric globin with a bis-histidyl six-coordinate"]
heme-iron protein — but bis-histidyl requires two histidines, and UniProt's own feature
table annotates the distal ligand as Gln792. Three independent primary papers say Gln. The
FUNCTION prose predates the 2024–2026 biochemistry; the feature table is right.

Test 3 — is `GO:0019825 oxygen binding` wrong? No, and this is where I nearly made the mirror error.

The tempting move is to knock the oxygen term down: ADGB is a hexacoordinate globin whose
distal site is occupied, autoxidation is extreme, and the primary paper says so outright:
PMID:38725499

But read the term's definition, not its label. GO:0019825 is defined as, in full,
"Binding to oxygen (O2)." It asserts nothing about transport, delivery or physiological role.
And the same paper did observe an oxy complex and measure its association rate constant
(~0.8 × 10⁶ M⁻¹ s⁻¹; the oxyform is observable transiently by stopped-flow). So the term is
true as chemistry and demonstrated, and the correct action is KEEP_AS_NON_CORE, not
removal.

What the autoxidation data do refute are the physiological terms that GOA does not
carry: GO:0005344 oxygen carrier activity ("Binding to oxygen and delivering it to an
acceptor molecule or a specific location") and GO:0019826 oxygen sensor activity. Neither is
annotated, neither should be, and the "except for the possibility of oxygen sensing" clause is
an authors' hedge, not evidence for the second.

The measured chemistry points elsewhere:
PMID:38725499
PMID:38725499 — unusual in the globin
superfamily and characteristic of NO-storage hemoproteins — and
PMID:38725499

Nitrite reductase activity is replicated by a second, independent laboratory:
PMID:39719941
(kcat/KM 0.046 → 0.102 mM⁻¹ s⁻¹ on CaM binding), and a third paper mutates the distal Gln and
finds Q12Y further enhances it PMID:42372363. Honest caveat, from the authors themselves:
PMID:39719941 — every
measurement is on the isolated recombinant globin domain, not the full-length protein.

IBA propagation: checked, and clean in both directions

WITH/FROM on the three IBA rows is MGI:MGI:3605549|PANTHER:PTN002922607 (the two CC rows)
and MGI:MGI:3605549|PANTHER:PTN002922608 (the BP row).

MGI:MGI:3605549 resolves to G3UZ78 = ADGB_MOUSE, Swiss-Prot reviewed, 1657 aa — the
true 1:1 ortholog of the 1667-aa human protein, not a paralog.
Paralog-transfer check: negative, and structurally impossible here. PANTHER PTHR46298
("Androglobin-like") has exactly two reviewed (Swiss-Prot) members — human ADGB and
mouse Adgb — both in subfamily PTHR46298:SF1. (The family's cached total is 1670 proteins
over 3237 taxa; the 2 is the reviewed subset, and I state it that way deliberately.) There
is no divergent clade member that could donate the wrong biology.
Donor-precision check (the ACRV1 test): negative. Asked not merely whether the donor
carries its own evidence but which term. QuickGO on G3UZ78 returns, for each propagated
term, the donor's own experimental annotation at exactly the same term — never above it:

propagated to human	donor's own evidence	reference
GO:0007286 spermatid development	IMP	PMID:36995441
GO:0097225 sperm midpiece	IDA	PMID:35700329
GO:0097227 sperm annulus	IDA	PMID:35700329

No downward MODIFY is warranted, and no upward over-reach occurred.
- Complex-projection check (the ACTR8 test): negative, in the benign direction.
PMID:35700329 annotates 8 annotations over 2 distinct entities (mouse Adgb and mouse
Sept10) and PMID:36995441 5 over 3 (Adgb, Cfap69, Spef2) — both fully returned, not
paginated. Critically, the functional/phenotype terms stay on the perturbed gene:
GO:0007283 IMP and GO:0007286 IMP are on Adgb alone. The terms that spread are
GO:0005515 (which is what IPI means) and co-localisation CC rows. This is parallel
per-protein curation, not a complex-level projection.

Redundancy worth recording: two pipelines, one donor, two papers

GO:0007286, GO:0097225 and GO:0097227 are each annotated twice on human ADGB — once
by PAINT (IBA) and once by Ensembl Compara (GO_REF:0000107, ECO:0000265) — and all six rows,
plus the two Compara-only rows (GO:0007283, GO:0036126), trace to the same mouse Adgb
experimental annotations from the same two papers. That is 8 of 13 rows resting on two
publications and one ortholog. Not an error, and I have not marked it as one, but anyone
counting independent support for this gene should know the effective N.

The real gap: human experiments exist and none of them is curated

Pharos: Tdark, and human ADGB has zero experimental GO annotations — yet:

the human recombinant globin domain binds heme
PMID:22115833;
the human globin domain binds NO and has nitrite reductase activity PMID:38725499,
replicated [PMID:39719941, PMID:42372363];
human patient variants disrupt CaM binding
PMID:36995441
and a globin+IQ construct binds CaM directly
PMID:35700329;
human partners were validated by co-IP
PMID:36995441
and PMID:41834962;
human sperm phenotypes
PMID:38385883.

Three MF terms are therefore proposed as NEW: GO:0005516 calmodulin binding,
GO:0070026 nitric oxide binding, GO:0098809 nitrite reductase activity. GOA carries no
calmodulin-binding annotation for ADGB in either species, which is the clearest miss.

GO:0050421 nitrite reductase (NO-forming) activity was checked and rejected: its
definition is cytochrome-c-specific ("nitric oxide + Fe(III)-[cytochrome c] + H2O = ..."),
i.e. the cd1-type enzyme, not a deoxyferrous globin reducing nitrite. GO:0098809 is the
correct level. Read the definition, not the label.

Cilium beyond sperm

The GO:0031514 motile cilium IEA comes from UniProtKB-SubCell:SL-0117 ("Flagellum"), whose
own GO mapping is GO:0031514. It is independently well supported, and not only in sperm:
PMID:33453283 and
PMID:33453283;
in Tetrahymena ADGB is a central-apparatus subunit
PMID:34083607,
though notably PMID:34083607 — a
useful negative that argues ADGB is not a core motility component of the projection.

Provider assessment (affinage)

gates_passed: True, faith_pct 100.0, 9 citations, all numeric PMIDs (no PMID:bio_*
preprint ids), all nine resolving to the correct papers by title. Retraction / erratum /
expression-of-concern check run over all nine via CommentsCorrections/RefType on each
article's own record plus a Crossref updated-by lookup for the null-PMID corrigendum
case: all clean (the checker was break-tested against the campaign's three known positive
controls and against a clean control; the one Crossref 404, on the 2026 Chinese-language
paper, is reported rather than silently swallowed).

But affinage's recall was the problem, not its precision. A PubMed search for
androglobin OR ADGB[tiab] returns 59 records; affinage cited 9 and missed the two papers
that decide this review:

PMID:38725499 (Chem Sci 2024) — the only full biophysical characterisation of the
globin domain, and the source of the O2/NO/nitrite/autoxidation data;
PMID:42372363 (Spectrochim Acta 2026) — names and mutates the distal Gln in its title.

It also missed PMID:33453283 (the FOXJ1/ciliogenesis primary paper — affinage cited the
secondary PMID:37158461 instead) and PMID:38786048. Lesson for the brief: a provider
record that passes its gates can still have a recall failure that inverts a verdict. Here,
relying only on affinage's set, GO:0019825 oxygen binding had no experimental anchor either
way and the distal-Gln finding was invisible.

Verdict summary

#	term	evidence	action
1	GO:0007286 spermatid development	IBA	ACCEPT
2	GO:0097225 sperm midpiece	IBA	ACCEPT
3	GO:0097227 sperm annulus	IBA	ACCEPT
4	GO:0004198 Ca-dependent Cys endopeptidase	IEA InterPro	REMOVE
5	GO:0006508 proteolysis	IEA InterPro	MARK_AS_OVER_ANNOTATED
6	GO:0019825 oxygen binding	IEA InterPro	KEEP_AS_NON_CORE
7	GO:0020037 heme binding	IEA InterPro	ACCEPT (core)
8	GO:0031514 motile cilium	IEA SubCell	ACCEPT
9	GO:0007283 spermatogenesis	IEA Compara	ACCEPT
10	GO:0007286 spermatid development	IEA Compara	ACCEPT
11	GO:0036126 sperm flagellum	IEA Compara	ACCEPT
12	GO:0097225 sperm midpiece	IEA Compara	ACCEPT
13	GO:0097227 sperm annulus	IEA Compara	ACCEPT
+	GO:0005516 calmodulin binding	IPI	NEW
+	GO:0070026 nitric oxide binding	IDA	NEW
+	GO:0098809 nitrite reductase activity	IDA	NEW

Curator-precedent survey (run to test my own term choices against GOA practice)

Queried QuickGO for what the four characterised human globins already carry, because a term
choice defended only from definitions is weaker than one that also matches what curators do.

The PR reviewer's fair objection to the first version of this table: it was pasted from an
ad-hoc query and so unverifiable from the checkout, since the comparator genes are not in this
repo. It is now generated by ADGB-bioinformatics/globin_term_precedent.py, which additionally
asserts the three claims below, so a change at QuickGO fails loudly rather than leaving
stale numbers sitting in prose. Regenerate and diff with
uv run python globin_term_precedent.py --check-notes.

	GO:0019825 O2 binding	GO:0020037 heme	GO:0098809 nitrite reductase
neuroglobin Q9NPG2	IBA + IDA + IEA	IEA	IDA
cytoglobin Q8WWM9	IDA + IEA	IBA + IEA	IDA
myoglobin P02144	IEA	IEA	IBA + IDA
haemoglobin alpha P69905	IEA	IBA + IEA	-

Three consequences, each of which strengthens a call I had made on other grounds:

GO:0019825 KEEP is precedented, not idiosyncratic. Neuroglobin and cytoglobin are
hexacoordinate globins that are not oxygen transporters, and both hold the term by IDA.
Stripping it from ADGB while its nearest analogues keep it would be inconsistent.
GO:0098809 is the term GOA actually uses for globin nitrite reductase activity - all
three characterised globins hold it by IDA - and none of them uses the GO:0050421
child, independently corroborating my rejection of that term on definitional grounds.
GO:0070026 is precedented for this exact chemistry. The five human holders, with
their own evidence codes rather than one blanket code: CBS IDA, THAP4/nitrobindin
IDA, the haemoglobin complex CPX-2158 IDA, GSTP1 NAS, and GUCY1B1 IEA - soluble
guanylate cyclase, the five-coordinate NO hemoprotein Reeder et al. explicitly name as
ADGB's comparator. So the comparator named in the paper does hold the term I am proposing,
but only by IEA; the experimental precedent comes from CBS, THAP4 and haemoglobin.
My first wording said the others "also" hold it by IDA, which could be read as covering
GUCY1B1 too. It does not, and the codes are now itemised on every surface.

Null part of the same survey, recorded rather than dropped: no individual monomeric globin
carries GO:0070026; only the haemoglobin complex does. So ADGB would be the first
single-chain globin with the term. That is a consequence of how unusual its NO chemistry is
rather than a reason to withhold it, but it should be visible to whoever curates it.

Checks run that came back negative (recorded so the next reviewer knows they were run)

Paralog transfer into the IBA set — negative; the PANTHER family's reviewed membership
is human + mouse ADGB only.
IBA landing above its donor (ACRV1 pattern) — negative; donor and target hold the
identical term in all three cases.
Complex-level phenotype projection (ACTR8 pattern) — negative; phenotype terms stay on
the perturbed gene.
Retraction / erratum / expression of concern / Crossref-only corrigendum — negative on
all 9 affinage citations and all 6 additional papers cited here.
Stub row collapse (ADAMTSL5 pattern) — negative; 13 = 13 = 13.
Predicted ROLE_CONFLATION between the protease and globin halves — not found as a
cross-domain conflation; the two domain signatures produced cleanly separated term sets
(IPR001300 → the two proteolysis terms, IPR012292 → the two heme/O2 terms). The defect is
within one signature's pair, not across them.

Process notes

The first version of my retraction checker read DOIs with art.iter("ArticleId"), which
walks into the reference list, so it reported an eLife paper's DOI as a JBC one and a
2026 paper's as a 1995 Nature Struct Biol one. Five of nine DOIs were wrong and the check
still "passed". Fixed by scoping to PubmedData/ArticleIdList; the discrepancy was the bug
report, exactly as the brief says.
The self-test's cross-matrix robustness line printed "BLOSUM62=2 BLOSUM45=3" — a two-vs-three
disagreement I chased rather than rationalised. It turned out to be variation in which
reference aligns its Cys column, while the ADGB position is invariant at C132. Reporting
it per-residue rather than per-triad turned an apparent instability into the strongest part
of the result — and revealed that one model (BLOSUM80) manufactures a lone His "match" that
a single-model run would have reported as partial triad retention.
The MEROPS catalytic-type regex initially returned UNPARSED for CAPN1/2/3 because their
pages are followed by "Peplist" rather than "NC-IUBMB". Re-anchored to MEROPS's controlled
vocabulary (longest-first, so "Non-peptidase homologue" cannot be shadowed) and guarded in
the self-test with both a must-parse assertion and a must-discriminate assertion, plus
positive and negative vocabulary probes. 7/7 now parse.
just validate silently de-duplicated cache/go/terms.csv. Computing the change as
multiset differences rather than reading the diff showed the working tree at 9070 rows
against the merge base's 9071: one net addition (GO:0097227, genuinely new — origin/main
does not have it) and two silent deletions, one copy each of GO:0001675 and
GO:0009566. Those are exactly the two pre-existing duplicates the campaign brief says to
leave alone. Fixed by git checkout HEAD -- cache/go/terms.csv (the merge base, not
origin/main, which has since moved and would have imported four rows from sibling
branches), then appending my single row without re-sorting. Re-ran just validate and
re-checked: stable, no re-append, dup profile preserved.
New for the brief: the documented failure mode is validate dropping rows; this run it
dropped rows by fixing something — a tidy-up that is correct in itself but out of scope for
a gene PR and invisible in a +/--heavy diff, because every reordered line appears as both.
The set-difference check catches it; reading the diff does not.
The pre-write hook .claude/hooks/validate_ai_review_pretool_hook.py computes
project_root from its own file location, so it validated my YAML against the session
directory rather than my worktree. That tree is on another agent's branch, lacks
genes/human/ADGB/ entirely, and holds different publications/ copies — several
abstract-only where mine have full text. Every one of its 12 errors was an artefact of the
wrong root, and complying would have meant dropping the Results-section quotations that the
GO:0006508 and GO:0019825 calls rest on. The file was therefore written via a staging
path and the identical validation run in the correct tree with just validate human ADGB
(passing), plus checkquotes.py (72 quotes, 0 problems) and the committed audit script.

Round-2 note: the blocking fix was made by the maintainer, not by me

2ee73035c was pushed directly to paint/ADGB by the repository owner while I was preparing my
own fix for the same two points, and it is the better wording, so it stands unchanged. It
resolved the reviewer's blocking item (GO:0007283 ACCEPT -> KEEP_AS_NON_CORE, because the
row's own summary already described the term as non-core while ActionEnum defines ACCEPT as
retaining a core function) and the reviewer's second non-blocking item (hedging the flat
"has nitrite reductase activity" in description to the isolated-domain, millimolar-K_M caveat
the annotation row already carried).

I verified the reviewer's blocking point independently before conceding, and it is exactly
scoped: GO:0007283 was the only ACCEPT row whose term is absent from core_functions,
and the converse check is also clean - no non-ACCEPT row holds a term that core_functions
uses.

That invariant is now genuinely enforced, and the first version of this sentence was false.
Round 3 of the PR review caught it: I had written "enforced rather than checked by eye" while
the check itself lived only in a throwaway patch script under /tmp, which ran once and was
never committed. audit_adgb_review.py had not been modified since the first commit and
contained no occurrence of core_functions at all. The verification had genuinely happened -
the scoping result I reported was correct - but a verification you performed is not a
verification that exists, and a durable artifact was left claiming otherwise.

It is now check F in audit_adgb_review.py, in both directions: every ACCEPT row's term must
appear in core_functions, and every core_functions term must be backed by a row whose action
is ACCEPT or NEW. The reverse direction is the one that would otherwise have gone unwritten,
and unwritten is not the same as passing. Both are break-tested, plus a third mutation for a
core_functions term with no annotation row at all.

The decisive check is not the self-test but a regression test against history: running check F
against the YAML at commit 6ff257b6f - the version the reviewer blocked - fires on exactly
GO:0007283, and against the current file it is clean. That is what makes the enforcement claim
checkable rather than another assertion.

Rule, from three genes in one night: when you write that something is enforced, the same push
must contain the enforcement, and you confirm it by grepping the script - not by remembering
that you ran the check.

Process lesson for the campaign brief. My worktree's HEAD had silently advanced to the
maintainer's commit. I discovered it only because a patch script asserted its anchor was
present and refused to run when it was not - the string it expected had already been
rewritten. Without that assertion the edit would have been a silent no-op, or worse, a
replace() on stale text that reverted someone else's fix. This is the anchor-assertion rule
paying off against a case it was not written for: it was written to catch my drift, and it
caught someone else's concurrent commit. Before any fix round, re-read the file from disk and
git fetch; do not assume your branch is where you left it.

Bioinformatics Results

(RESULTS.md)

ADGB (Q8N7X0) - do the calpain and globin domains retain their functional residues?

Generated by adgb_sites.py. Reproduce with:

uv run python adgb_sites.py --self-test              # guards, both directions
uv run python adgb_sites.py --json results.json \
                            --results-md RESULTS.md  # this file

Every number below is interpolated from the same run that printed the tables,
so this file cannot drift from the measurement. A hand-edit is reverted by the
next run.

Question

GOA gives ADGB four InterPro IEA rows, two from each domain signature:

signature	GO term
IPR001300 Peptidase_C2_calpain_cat	GO:0004198 calcium-dependent cysteine-type endopeptidase activity
IPR001300 Peptidase_C2_calpain_cat	GO:0006508 proteolysis
IPR012292 Globin/Proto	GO:0019825 oxygen binding
IPR012292 Globin/Proto	GO:0020037 heme binding

A domain's name is not an activity. Does ADGB keep the residues each activity needs?

Subject: Q8N7X0 ADGB_HUMAN / Androglobin, 1667 aa, reviewed=True.
UniProt annotates the calpain catalytic domain at 70-411 and the globin domain in two parts, (763, 890) and (936, 968) (circular permutation).

Q1. Calpain catalytic triad: NOT retained

Each of the 6 reviewed reference calpains carries three UniProt
Active site features. ADGB carries 0.

Aligning each reference's catalytic domain to ADGB 70-411 under 4 substitution/gap models (BLOSUM62, BLOSUM45, BLOSUM80, PAM250) and
reading the ADGB residue in each reference-active-site column:

triad role	aligned columns	ADGB positions hit	columns where ADGB has the catalytic residue
nucleophile Cys	15	[132, 146]	11/15, always at ['C132']
general base His	22	[267, 320, 321, 326, 332, 334, 352]	1/22 ['H267']
Asn	22	[319, 343, 344, 346, 353, 357]	0/22 (none)

Read per-residue rather than per-triad (a single model's triad count is an
alignment artefact, not a measurement):

The nucleophile column converges: whenever a reference's catalytic Cys
aligns to a Cys in ADGB it is always the same residue, C132,
in 11 of 15 columns. Which references reach it varies by model; the
ADGB position does not.
The general-base His column does not converge: 1 of 22 columns,
scattered over ADGB positions [267, 320, 321, 326, 332, 334, 352]. The lone hit
(H267) appears under one model only and at a position no
other model selects - the signature of alignment noise, not conservation.
The Asn column never yields an Asn: 0 of 22.

A papain-fold cysteine protease cannot catalyse without the general-base
histidine that deprotonates the nucleophile. A retained Cys with no His and no
Asn is a fold, not an active site.

Independent corroboration: MEROPS classifies ADGB as a non-peptidase homologue

This does not depend on the alignment at all.

accession	gene	MEROPS	catalytic type
Q8N7X0	ADGB	`C02.972`	Non-peptidase homologue
P07384	CAPN1	`C02.001`	Cysteine
P17655	CAPN2	`C02.002`	Cysteine
P20807	CAPN3	`C02.004`	Cysteine
Q9Y6W3	CAPN7	`C02.029`	Cysteine
Q9HC96	CAPN10	`C02.018`	Cysteine
O75808	CAPN15	`C02.031`	Cysteine

All 6 reference calpains: Cysteine. ADGB: Non-peptidase homologue, and ADGB is the holotype of that entry.
The identifier block is consistent: reference suffixes [1, 2, 4, 18, 29, 31] against ADGB's 972.

UniProt says the same thing in its CAUTION: "The calpain domain lacks the
conserved active site residues. Probably catalytically inactive as a
calcium-dependent cysteine-type endopeptidase."

Verdict: GO:0004198 is not supported. The measurement refines UniProt's
wording - it is not that all the active-site residues are gone; the nucleophile
survives and the general base and Asn do not.

Caveat that must be stated

Q1 CAVEAT: ADGB carries ZERO UniProt 'Active site' features, so the lands_on_subject_annotated_site condition is VACUOUS in Q1 and its all-'no' column is not a measurement. That absence is itself the signal: UniProt annotates the Calpain catalytic domain on ADGB but propagates no catalytic residues into it, whereas all 6 reference calpains carry 3 each. The condition IS load-bearing in Q2, where ADGB has 2 annotated heme-iron Binding sites and it separates the on-register Mb/Ngb/Cygb alignments from the off-register HBB one.

Q2. Globin heme ligands: proximal His retained, distal His replaced by Gln

Same method against reviewed globins whose heme-iron ligands UniProt annotates.
Here ADGB does have its own annotated sites, so the
lands_on_subject_annotated_site condition is live and does the discriminating.

reference	%id	reference site	-> ADGB	residue match	on an ADGB-annotated site	role
P02144 MYG_HUMAN	21.9	H65	Q792	no	yes	O2
P02144 MYG_HUMAN	21.9	H65	Q792	no	yes	nitrite
P02144 MYG_HUMAN	21.9	H94	H824	yes	yes	proximal binding residue
P69905 HBA_HUMAN	22.7	H59	Q792	no	yes	O2
P69905 HBA_HUMAN	22.7	H88	Q821	no	no	proximal binding residue
P68871 HBB_HUMAN	20.3	H3	H763	yes	no	(2R)-2,3-bisphosphoglycerate
P68871 HBB_HUMAN	20.3	H64	H830	yes	no	distal binding residue
P68871 HBB_HUMAN	20.3	H93	Q854	no	no	proximal binding residue
P68871 HBB_HUMAN	20.3	H144	E887	no	no	(2R)-2,3-bisphosphoglycerate
Q9NPG2 NGB_HUMAN	22.7	H64	Q792	no	yes	distal binding residue; reversible
Q9NPG2 NGB_HUMAN	22.7	H96	H824	yes	yes	proximal binding residue
Q8WWM9 CYGB_HUMAN	18.0	H81	Q792	no	yes	distal binding residue
Q8WWM9 CYGB_HUMAN	18.0	H113	H824	yes	yes	proximal binding residue

Distal position (ADGB Q792). 5 reference columns land on it, from 4 distinct globins, and the reference
residue is H in every one. ADGB has Q.
Proximal position (ADGB H824). 3 reference columns land on it and 3 of 3 match: ADGB retains the proximal histidine.
5 columns are off-register (they do not land on either ADGB
annotated site). Their apparent matches are noise - the HBB alignment in
particular 'matches' a distal His at a position UniProt does not annotate while
failing the proximal one. Sequence identity does not predict register here
(CYGB at 18.0% is on-register for both sites; HBB at 20.3% is on-register for neither) - the
annotated-site condition does.

Verdict: the globin domain is intact as a heme protein, but it is a His/Gln
hexacoordinate globin, not a bis-histidyl one.

This is confirmed independently by the primary literature, in three places that
agree with the sequence and with each other:

Reeder et al. 2024 (PMID:38725499) state the ferric coordination as
His-Fe(III)-X with "X = His for Cygb and Gln for Adgb", and label the
alignment position "the distal histidine/glutamine".
Nie et al. 2025 (PMID:39719941) label Fig. 1B "the distal Gln30" and conclude
"Gln30 in the heme distal site may coordinate to the heme iron in the ferrous
state" - their construct starts at UniProt 763, so their His62/res30 are
UniProt H824/Q792 exactly (spacing 32 in both numberings).
Ren et al. 2026 (PMID:42372363) name it in the title and mutate it: "the heme
distal residue Gln12 through the generation of Q12H and Q12Y mutants".

UniProt's own FUNCTION line is internally inconsistent with its feature table:
it says ADGB is a "chimeric globin with a bis-histidyl six-coordinate heme-iron
atom" while the feature table annotates the distal ligand as Q792. Worth reporting to UniProt.

What this does and does not settle

It settles that the calpain-domain-derived catalytic MF term has no residue
support, and that MEROPS and UniProt independently agree.
It settles that heme binding is structurally well founded (the proximal ligand
is retained and is the residue UniProt annotates).
It does not test oxygen binding, which is a ligand-binding measurement, not
a sequence one. See the notes file: an oxy complex is formed and its
association rate was measured (PMID:38725499), so GO:0019825 is true as
chemistry, while the same paper's autoxidation rate argues it is not a
physiological role.
It does not test whether ADGB contributes to SEPT10 cleavage by a non-catalytic
route, which is what the cell-based data actually show.

📄 View Raw YAML

id: Q8N7X0
gene_symbol: ADGB
product_type: PROTEIN
status: COMPLETE
taxon:
  id: NCBITaxon:9606
  label: Homo sapiens
description: >-
  Androglobin is the fifth and most structurally unusual mammalian globin: a large (1667 aa)
  chimeric protein in which an N-terminal calpain-like (peptidase C2) region is followed by a
  circularly permuted globin domain whose two halves are separated by an IQ calmodulin-binding
  motif, and then by a long C-terminal region ending in a coiled coil. The globin domain is a
  genuine heme protein - the recombinant human domain purifies with heme and shows a
  hexacoordinate ferrous spectrum - but it is not a bis-histidyl globin: the proximal F8
  histidine (His824) is retained while the distal E7 position is a glutamine (Gln792). It binds
  nitric oxide as an unusual five-coordinate complex, shows nitrite reductase activity in the
  isolated globin domain (at millimolar K_M, so its physiological significance is untested)
  that is enhanced by calmodulin binding at the IQ motif, and autoxidises three orders of magnitude
  faster than neuroglobin, so its measured chemistry points to nitric oxide handling rather
  than to oxygen storage or transport. The calpain-like region, by contrast, is a degenerate
  protease fold: it retains a cysteine at the aligned nucleophile position but has lost the
  catalytic histidine and asparagine, and MEROPS classifies androglobin as a non-peptidase
  homologue of family C2. Androglobin is expressed predominantly in post-meiotic male germ
  cells and, more broadly, in motile-ciliated cell types, where its transcription is driven by
  the ciliogenic factors FOXJ1 and RFX2. It localises to the sperm flagellum, midpiece and
  annulus, binds calmodulin, septin 10, CFAP69, SPEF2, TTC29 and CFAP47, and in the ciliate
  central apparatus is a component of the C1b/C1f supercomplex. Loss of androglobin in mice
  causes male infertility with defective spermatid maturation, abnormal head shaping and
  disrupted manchette, annulus and flagellum organisation, and bi-allelic human variants cause
  asthenozoospermia and oligoasthenoteratozoospermia with acrosome, mitochondrial-sheath and
  axonemal defects.
alternative_products:
- name: '1'
  id: Q8N7X0-1
- name: '2'
  id: Q8N7X0-2
  sequence_note: VSP_039243, VSP_039244
existing_annotations:
- term:
    id: GO:0007286
    label: spermatid development
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: involved_in
  supporting_entities:
  - MGI:MGI:3605549
  - PANTHER:PTN002922608
  review:
    summary: >-
      Accepted as a core biological process. The propagation was checked in all three of the
      ways this campaign has found defects, and came back clean in each. (i) The donor
      MGI:MGI:3605549 resolves to UniProtKB G3UZ78, ADGB_MOUSE, Swiss-Prot reviewed, 1657 aa -
      the true 1:1 ortholog of the 1667-aa human protein, not a paralog. (ii) A paralog transfer
      is structurally impossible on this node: PANTHER PTHR46298 "Androglobin-like" has exactly
      two reviewed (Swiss-Prot) members, human ADGB and mouse Adgb, both in subfamily
      PTHR46298:SF1, so there is no divergent clade member that could donate the wrong biology.
      The family's cached total is 1670 proteins over 3237 taxa; the count of two is the
      reviewed subset and is stated as such. (iii) Asking not merely whether the donor carries
      its own evidence but which term it carries, QuickGO shows mouse Adgb holds GO:0007286 by
      its own IMP from PMID:36995441 - the identical term, neither above nor below the
      propagated one - so no downward MODIFY is warranted. Human patient genetics corroborates
      the transfer independently: bi-allelic ADGB variants cause asthenozoospermia and
      oligoasthenoteratozoospermia with malformed spermatids.
    action: ACCEPT
    reason: >-
      Sole-ortholog donor carrying its own experimental annotation at exactly this term, in a
      two-member reviewed family with no paralog risk, and corroborated by human genetics.
    proposed_replacement_terms: []
    supported_by:
    - reference_id: PMID:35700329
      supporting_text: >-
        it locates to the sperm flagellum, the annulus, and the midpiece, and that it is crucial
        for male fertility and sperm formation
    - reference_id: PMID:38385883
      supporting_text: >-
        the spermatozoa from patients harboring ADGB variants showed multiple acrosome and
        flagellum malformations under light and electron microscopy
    propagation_review:
      root_cause: NO_FAILURE_CORE
      failure_modes: []
      source_entities:
      - source_id: MGI:MGI:3605549
        source_label: mouse Adgb (UniProtKB G3UZ78, ADGB_MOUSE, reviewed/Swiss-Prot, 1657 aa)
        source_status: SUPPORTS_TRANSFER
        comment: >-
          True 1:1 ortholog, resolved via UniProt xref:mgi-3605549 using the bare numeric id
          (the doubled MGI:MGI: form returns HTTP 400). It carries its own IMP to this exact
          term from PMID:36995441, so the propagation neither over-reaches nor lands above its
          donor.
      - source_id: PANTHER:PTN002922608
        source_label: PANTHER internal tree node in PTHR46298 (Androglobin-like)
        source_status: SUPPORTS_TRANSFER
        comment: >-
          An internal tree node, not a protein. Recorded as such rather than as unresolvable.
          Note the two CC rows on this gene use a different node, PTN002922607, so PAINT placed
          the BP and CC terms at separate nodes within a family whose reviewed membership is
          only human and mouse ADGB.
- term:
    id: GO:0097225
    label: sperm midpiece
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: is_active_in
  supporting_entities:
  - MGI:MGI:3605549
  - PANTHER:PTN002922607
  review:
    summary: >-
      Accepted. Same sole-ortholog donor as the spermatid-development row, and the donor holds
      GO:0097225 by its own IDA from PMID:35700329 - the same term, not a parent, so the
      ACRV1-style "propagation landed above its donor" defect is absent here. The mouse study
      localised Adgb along the whole flagellum including the midpiece by immunofluorescence in
      stage-12 and stage-15 spermatids and in epididymal sperm, and UniProt records the same
      placement. The donor's qualifier is located_in while PAINT uses is_active_in; that is the
      normal PAINT convention for a component where the gene product acts and is not worth a
      MODIFY on its own.
    action: ACCEPT
    reason: >-
      Ortholog donor with its own IDA at precisely this term; localisation independently
      recorded in UniProt and reproduced in human spermatogenic cells.
    proposed_replacement_terms: []
    supported_by:
    - reference_id: PMID:35700329
      supporting_text: >-
        it locates to the sperm flagellum, the annulus, and the midpiece, and that it is crucial
        for male fertility and sperm formation
    - reference_id: file:human/ADGB/ADGB-uniprot.txt
      supporting_text: along the whole sperm flagellum. Detected in the annulus of the sperm
    propagation_review:
      root_cause: NO_FAILURE_CORE
      failure_modes: []
      source_entities:
      - source_id: MGI:MGI:3605549
        source_label: mouse Adgb (UniProtKB G3UZ78, ADGB_MOUSE, reviewed/Swiss-Prot, 1657 aa)
        source_status: SUPPORTS_TRANSFER
        comment: >-
          Carries GO:0097225 by IDA from PMID:35700329, the identical term. Checked for the
          ACTR8-style complex projection: that reference annotates 8 annotations over only 2
          distinct entities (Adgb and Sept10) and its phenotype terms stay on the perturbed
          gene, so it is parallel per-protein curation, not a projection.
      - source_id: PANTHER:PTN002922607
        source_label: PANTHER internal tree node in PTHR46298 (Androglobin-like)
        source_status: SUPPORTS_TRANSFER
        comment: Internal tree node, not a protein. Shared with the sperm-annulus IBA row.
- term:
    id: GO:0097227
    label: sperm annulus
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: is_active_in
  supporting_entities:
  - MGI:MGI:3605549
  - PANTHER:PTN002922607
  review:
    summary: >-
      Accepted. The donor holds GO:0097227 by its own IDA from PMID:35700329, again the exact
      term. This is the most specific and most informative of the three localisations: mouse
      Adgb and Sept10 co-localise in the annulus of stage-15 spermatids and mature sperm, and
      loss of Adgb mislocalises Sept10, which is the mechanistic link between the localisation
      and the manchette/annulus phenotype. UniProt records the same annulus localisation.
    action: ACCEPT
    reason: >-
      Ortholog donor with its own IDA at precisely this term, and the annulus is where the
      gene's best-characterised interaction and phenotype are located.
    proposed_replacement_terms: []
    supported_by:
    - reference_id: file:human/ADGB/ADGB-uniprot.txt
      supporting_text: along the whole sperm flagellum. Detected in the annulus of the sperm
    propagation_review:
      root_cause: NO_FAILURE_CORE
      failure_modes: []
      source_entities:
      - source_id: MGI:MGI:3605549
        source_label: mouse Adgb (UniProtKB G3UZ78, ADGB_MOUSE, reviewed/Swiss-Prot, 1657 aa)
        source_status: SUPPORTS_TRANSFER
        comment: Carries GO:0097227 by IDA from PMID:35700329, the identical term.
      - source_id: PANTHER:PTN002922607
        source_label: PANTHER internal tree node in PTHR46298 (Androglobin-like)
        source_status: SUPPORTS_TRANSFER
        comment: Internal tree node, not a protein. Shared with the sperm-midpiece IBA row.
- term:
    id: GO:0004198
    label: calcium-dependent cysteine-type endopeptidase activity
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  qualifier: enables
  supporting_entities:
  - InterPro:IPR001300
  review:
    summary: >-
      Removed. This is the textbook case of a domain's name being propagated into an activity,
      and the removal is argued positively rather than merely asserted. Three independent lines
      converge, and two of them do not depend on my alignment at all. First, the residues.
      Aligning the catalytic domains of six reviewed reference calpains (CAPN1, CAPN2, CAPN3,
      CAPN7, CAPN10, CAPN15) to ADGB 70-411 under four substitution and gap models, and reading
      the ADGB residue in each column anchored on the reference's own UniProt Active site
      feature, gives a sharply split result. The nucleophile cysteine is retained: 11 of 15
      aligned columns have a Cys in ADGB and it is always the same residue, C132, with the ADGB
      position invariant even though which reference reaches it varies by model. The general
      base histidine and the asparagine are not: 1 of 22 and 0 of 22 respectively, scattered
      over seven and six different ADGB positions, and the single His hit appears under one
      model only at a position no other model selects. A papain-fold cysteine protease cannot
      turn over without the general base that deprotonates the nucleophile, so a retained Cys
      with no His and no Asn is a fold, not an active site. Second, UniProt says the same thing
      in a CAUTION, and annotates zero Active site features on ADGB while all six reference
      calpains carry three each. Third, and independently of sequence analysis, MEROPS
      classifies androglobin as a non-peptidase homologue of family C2 and makes ADGB the
      holotype of that entry; the identifier block corroborates it, with the reference calpains
      at C02.001/.002/.004/.018/.029/.031 against ADGB at C02.972. The term additionally
      requires calcium dependence, for which there is no evidence of any kind on this protein -
      the calcium link in the literature runs through calmodulin binding at the IQ motif, which
      is a different thing.
    action: REMOVE
    reason: >-
      An InterPro domain signature has been read as an activity. The calpain fold is present
      but degenerate: the catalytic His and Asn are absent across six references and four
      alignment models, UniProt flags it in a CAUTION and annotates no active-site residues,
      and MEROPS independently classifies ADGB as a non-peptidase homologue with ADGB as the
      holotype. No experimental evidence supports calcium-dependent cysteine protease activity
      for ADGB in any organism. This is an electronic inference removed on biological grounds,
      not a curator's experimental call being second-guessed.
    proposed_replacement_terms: []
    supported_by:
    - reference_id: file:human/ADGB/ADGB-uniprot.txt
      supporting_text: The calpain domain lacks the conserved active site residues.
    - reference_id: file:human/ADGB/ADGB-bioinformatics/RESULTS.md
      supporting_text: >-
        A papain-fold cysteine protease cannot catalyse without the general-base histidine that
        deprotonates the nucleophile. A retained Cys with no His and no Asn is a fold, not an
        active site.
    - reference_id: file:human/ADGB/ADGB-bioinformatics/RESULTS.md
      supporting_text: >-
        All 6 reference calpains: Cysteine. ADGB: **Non-peptidase homologue**, and ADGB is the
        *holotype* of that entry.
    - reference_id: PMID:22115833
      supporting_text: >-
        The calpain-like region is homologous to the catalytic domain II of the large subunit of
        human calpain-7.
    propagation_review:
      root_cause: PROPAGATION_BAD
      failure_modes:
      - PSEUDO_OR_SUBACTIVITY_LOSS
      - FUNCTIONAL_DIVERGENCE
      source_entities:
      - source_id: InterPro:IPR001300
        source_label: Peptidase_C2_calpain_cat (calpain catalytic domain signature)
        source_status: SUPPORTS_SOURCE_BUT_NOT_TARGET
        comment: >-
          The signature itself is sound and ADGB genuinely matches the calpain catalytic fold -
          UniProt, PROSITE PS50203 and SMART CysPc all place the domain at 70-411. What fails is
          the InterPro2GO mapping from that fold to a catalytic activity, because ADGB is a
          fold-retaining pseudoenzyme that has lost the general base and the Asn. The defect is
          in the propagation, not in the source: this is why the root cause is PROPAGATION_BAD
          and not SOURCE_WEAK_OR_INFERRED, which my own analysis would contradict.
- term:
    id: GO:0006508
    label: proteolysis
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  qualifier: involved_in
  supporting_entities:
  - InterPro:IPR001300
  review:
    summary: >-
      Marked as over-annotated rather than removed, because two things are true at once and
      they pull in opposite directions. The route that produced this row is the same unsound
      one that produced the GO:0004198 row: InterPro2GO reading a degenerate calpain fold as a
      protease. On that basis alone the term would go. But there is a real, published
      observation that ADGB contributes to proteolysis of septin 10, and it must not be erased
      by a structural argument. Reading past the abstract shows exactly what was and was not
      shown. The assay is co-overexpression of ADGB and SEPT10 in HEK293 cells, with a
      dose-dependent 37 kDa SEPT10 fragment appearing in the presence of ADGB; the
      perturbations that reduced it were a whole-IQ-domain deletion and a whole-protease-domain
      deletion. There is no purified-protein cleavage assay, no protease inhibitor, and
      crucially no catalytic-residue point mutant - which is the experiment that would
      demonstrate catalysis, and for which there is no confident triad to target. The word
      "catalytic" does not appear in the paper, and the authors consistently write "contributes
      to" rather than "cleaves". A large deletion in a 1667-residue protein can abolish an
      activity by disrupting folding or complex assembly without the deleted region being the
      catalytic module. So the conclusion may well be right by a mechanism other than direct
      catalysis - ADGB delivering SEPT10 to another protease, for example - but it is not
      established for this gene by the route that produced the annotation. That is
      over-annotation, not error.
    action: MARK_AS_OVER_ANNOTATED
    reason: >-
      Derived from a catalytic domain signature that MEROPS and UniProt both hold to be
      non-catalytic in ADGB, so the inference route is unsound. Not removed, because a real
      in vitro observation of ADGB-dependent SEPT10 cleavage exists; that observation rests on
      co-overexpression and whole-domain deletion rather than on any demonstration that ADGB
      itself catalyses the bond hydrolysis, so it cannot carry the term on its own either.
    proposed_replacement_terms: []
    supported_by:
    - reference_id: PMID:35700329
      supporting_text: >-
        Collectively, these in vitro data suggest a scenario in which overexpressed ADGB
        proteolytically contributes to cleavage of overexpressed SEPT10 in an O2-independent but
        CaM-dependent manner.
    - reference_id: file:human/ADGB/ADGB-uniprot.txt
      supporting_text: 'Interacts with septin SEPT10; contributes to in vitro'
    - reference_id: file:human/ADGB/ADGB-uniprot.txt
      supporting_text: The calpain domain lacks the conserved active site residues.
    propagation_review:
      root_cause: PROPAGATION_BAD
      failure_modes:
      - PSEUDO_OR_SUBACTIVITY_LOSS
      source_entities:
      - source_id: InterPro:IPR001300
        source_label: Peptidase_C2_calpain_cat (calpain catalytic domain signature)
        source_status: SUPPORTS_SOURCE_BUT_NOT_TARGET
        comment: >-
          Same signature and same failure as the GO:0004198 row: the fold match is real, the
          activity inference is not. Recorded separately here because the biological-process
          term, unlike the molecular-function term, is not contradicted by independent data -
          it is merely unsupported by the route that produced it.
- term:
    id: GO:0019825
    label: oxygen binding
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  qualifier: enables
  supporting_entities:
  - InterPro:IPR012292
  review:
    summary: >-
      Kept, but as a non-core function - and the reasoning here runs opposite to the reflex.
      The tempting move is to remove it: ADGB is a hexacoordinate globin whose distal position
      is occupied, and the primary biophysical paper states outright that the extreme
      autoxidation rate means O2 binding is not a physiological function of the protein.
      Reading the term's definition rather than its label changes the answer. GO:0019825 is
      defined, in full, as "Binding to oxygen (O2)". It asserts nothing about transport,
      delivery, storage or physiological role. And the same paper that argues against a
      physiological role did observe an oxy complex and measure its association rate constant
      of about 0.8 x 10^6 M^-1 s^-1 by stopped-flow. Oxygen binding is therefore demonstrated
      chemistry, and the annotation is true as written. What the data do refute are the
      physiological oxygen terms, and GOA does not carry them: GO:0005344 oxygen carrier
      activity requires binding and delivering oxygen to an acceptor or a location, and
      GO:0019826 oxygen sensor activity requires responding to changes in oxygen level. Neither
      is annotated and neither should be added - the authors' clause about "the possibility of
      oxygen sensing" is an explicit hedge, not evidence. Two further observations reinforce
      keeping this non-core: the measured autoxidation rate of at least 2.6 per second is three
      orders of magnitude faster than neuroglobin's, and the SEPT10 cleavage assay in cells was
      explicitly repeated under 0.2 percent O2 with no difference, so the one cellular process
      linked to ADGB is oxygen-independent. Curator precedent agrees with keeping it: the
      two closest comparators, human neuroglobin (Q9NPG2) and cytoglobin (Q8WWM9), are also
      hexacoordinate globins that are not oxygen transporters, and GOA gives each of them
      GO:0019825 by IDA. Removing the term from ADGB while its nearest structural analogues
      retain it on the same kind of evidence would be inconsistent.
    action: KEEP_AS_NON_CORE
    reason: >-
      The term means only "binding to oxygen", and that binding has been measured on the human
      recombinant globin domain, so the annotation is correct as written. It is not a core
      function because the oxy complex is only transiently observable and autoxidises three
      orders of magnitude faster than neuroglobin's, and the protein's measured chemistry is
      oriented towards nitric oxide rather than oxygen.
    proposed_replacement_terms: []
    supported_by:
    - reference_id: PMID:38725499
      supporting_text: >-
        This remarkable autoxidation rate strongly suggests that O2 binding is not a
        physiological function of the protein except for the possibility of oxygen sensing.
    - reference_id: PMID:38725499
      supporting_text: >-
        With rapid autoxidation and high nitrite reductase activity, the globin appears to be
        more tailored toward nitric oxide homeostasis or buffering.
- term:
    id: GO:0020037
    label: heme binding
  evidence_type: IEA
  original_reference_id: GO_REF:0000002
  qualifier: enables
  supporting_entities:
  - InterPro:IPR012292
  review:
    summary: >-
      Accepted as a core molecular function, and this is the half of the chimera where the
      domain-derived IEA turns out to be right. It is supported experimentally in human and
      structurally at residue level. Experimentally: the recombinant human globin domain has
      been expressed and purified with heme by three independent groups, showing a Soret band
      at 411 nm in the ferric state shifting to 423 nm on reduction with visible bands at 529
      and 558 nm, an extinction coefficient determined by the hemochromogen method, and EPR
      characterisation. Structurally: aligning ADGB's globin domain to reviewed globins whose
      heme-iron ligands UniProt annotates, and requiring both residue identity and that the
      column land on one of ADGB's own annotated sites, the proximal F8 histidine is retained
      in 3 of 3 on-register references (myoglobin H94, neuroglobin H96, cytoglobin H113 all map
      to ADGB H824). The annotated-site condition is doing real work here rather than being
      decorative: sequence identity alone does not predict register, since cytoglobin at 18.0
      percent is on-register for both ligands while haemoglobin beta at 20.3 percent is
      on-register for neither and produces a spurious distal "match" on a histidine UniProt
      does not annotate. One correction to UniProt belongs on this row rather than as a change
      to the GO term: the protein is a His/Gln hexacoordinate globin, not a bis-histidyl one.
      The distal E7 position is Gln792, confirmed by UniProt's own feature table, by the
      Swiss-Prot sequence read directly, and by three primary papers, while UniProt's FUNCTION
      prose still says bis-histidyl. That affects how the heme chemistry should be described,
      not whether heme is bound.
    action: ACCEPT
    reason: >-
      Directly demonstrated on the human protein by three independent laboratories, and
      structurally well founded - the proximal heme-iron ligand is retained and is precisely
      the residue UniProt annotates. Core to what androglobin is.
    proposed_replacement_terms: []
    supported_by:
    - reference_id: PMID:22115833
      supporting_text: >-
        The recombinantly expressed human globin domain exhibits an absorption spectrum
        characteristic of hexacoordination of the heme iron atom.
    - reference_id: PMID:39719941
      supporting_text: >-
        These observations suggest that Gln30 in the heme distal site may coordinate to the heme
        iron in the ferrous state.
    - reference_id: file:human/ADGB/ADGB-bioinformatics/RESULTS.md
      supporting_text: >-
        **Proximal position (ADGB H824).** 3 reference columns land on it and 3 of 3 match: ADGB
        retains the proximal histidine.
    - reference_id: PMID:38725499
      supporting_text: X = His for Cygb and Gln for Adgb
- term:
    id: GO:0031514
    label: motile cilium
  evidence_type: IEA
  original_reference_id: GO_REF:0000044
  qualifier: located_in
  supporting_entities:
  - UniProtKB-SubCell:SL-0117
  review:
    summary: >-
      Accepted. This is the Swiss-Prot subcellular-location keyword pipeline working correctly:
      SL-0117 is "Flagellum", whose own curated GO mapping is GO:0031514, and UniProt's
      SUBCELLULAR LOCATION for ADGB is "Cell projection, cilium, flagellum". Unusually for a
      keyword-derived row, the term is supported well beyond the sperm flagellum that motivated
      it, which is why the broader motile-cilium term is the right level rather than an
      over-reach. ADGB expression across human tissues is specifically associated with
      motile-ciliated cell types, its promoter is a direct target of the ciliogenic
      transcription factors FOXJ1 and RFX2, and overexpressing full-length ADGB increases the
      number of ciliated cells. In Tetrahymena, Adgb is a subunit of the C1b/C1f supercomplex of
      the ciliary central apparatus. A useful counterweight kept in view: deleting Adgb in
      Tetrahymena caused only minor changes in ciliary motility, unlike deletion of its
      partners Spef2A or Cfap69, so ADGB is a resident of motile cilia rather than a core motor
      or structural component of the projection - which is exactly what a located_in term
      claims and no more.
    action: ACCEPT
    reason: >-
      Correct keyword-to-GO mapping, and independently supported in three systems - human
      motile-ciliated cell types with FOXJ1/RFX2 regulation, mouse sperm flagellum, and the
      ciliate central apparatus.
    proposed_replacement_terms: []
    supported_by:
    - reference_id: PMID:33453283
      supporting_text: specifically being associated with cell types forming motile cilia
    - reference_id: PMID:33453283
      supporting_text: >-
        cell culture studies indicated an ADGB-dependent increase in the number of ciliated
        cells upon overexpression of the full-length protein, confirming a
        ciliogenesis-associated role of ADGB in mammals
    - reference_id: PMID:34083607
      supporting_text: >-
        C1b/C1f contains several evolutionarily conserved proteins: Spef2A, Cfap69,
        Cfap246/LRGUK, Adgb/androglobin
- term:
    id: GO:0007283
    label: spermatogenesis
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  qualifier: involved_in
  supporting_entities:
  - UniProtKB:G3UZ78
  - ensembl:ENSMUSP00000134378
  review:
    summary: >-
      Correct, but kept as non-core. Ensembl Compara transfer from the 1:1 mouse ortholog, whose
      own annotation is an IMP from the knockout study - Adgb-null males are infertile with reduced sperm
      concentration and motility, abnormal spermatid elongation and increased apoptosis in the
      cauda epididymis. Checked for the ACTR8-style complex projection and it is absent: the
      supporting reference annotates only 2 distinct entities in total and its phenotype terms,
      GO:0007283 IMP and GO:0007286 IMP, sit on Adgb alone, the gene actually knocked out. The
      transfer is also corroborated directly in human rather than resting on the mouse alone:
      bi-allelic ADGB variants have been found in infertile men in three independent cohorts.
      Kept as a non-core parent of the more informative spermatid development term
      GO:0007286, which is what carries the process in core_functions.
    action: KEEP_AS_NON_CORE
    reason: >-
      Ortholog transfer from a knockout-based IMP, corroborated by human patient genetics in
      three independent cohorts; no projection artefact.
    proposed_replacement_terms: []
    supported_by:
    - reference_id: PMID:35700329
      supporting_text: >-
        it locates to the sperm flagellum, the annulus, and the midpiece, and that it is crucial
        for male fertility and sperm formation
    - reference_id: file:human/ADGB/ADGB-uniprot.txt
      supporting_text: formation and maturation of elongating spermatids, thus playing an
- term:
    id: GO:0007286
    label: spermatid development
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  qualifier: involved_in
  supporting_entities:
  - UniProtKB:G3UZ78
  - ensembl:ENSMUSP00000134378
  review:
    summary: >-
      Accepted. This is the same conclusion as the IBA row above, reached by a second and
      independent pipeline: Ensembl Compara transferring mouse Adgb's IMP from PMID:36995441.
      Worth recording explicitly rather than passing over, because it means GO:0007286 is
      annotated twice on this gene and the duplication is not additional evidence - both rows
      trace to the same single ortholog and the same paper. Across the whole record, 8 of the
      13 GOA rows rest on two publications and one donor organism. That is not an error and I
      have not marked it as one, but anyone counting independent support for ADGB should know
      the effective N.
    action: ACCEPT
    reason: >-
      Same well-founded ortholog transfer as the IBA row, by a different pipeline. Correct, but
      it is a duplicate rather than corroboration.
    proposed_replacement_terms: []
    supported_by:
    - reference_id: PMID:36995441
      supporting_text: >-
        Spermatogenesis was also abnormal, with malformation of both elongating and elongated
        spermatids
- term:
    id: GO:0036126
    label: sperm flagellum
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  qualifier: located_in
  supporting_entities:
  - UniProtKB:G3UZ78
  - ensembl:ENSMUSP00000134378
  review:
    summary: >-
      Accepted. The donor holds GO:0036126 by its own IDA from PMID:35700329, so the transfer
      lands on exactly the term the mouse data support. Human immunofluorescence independently
      places ADGB in the flagella of human spermatogenic cells, and the human loss-of-function
      phenotype - short, angled, coiled and absent tails with disrupted 9+2 axonemal structure
      and a disorganised mitochondrial sheath - is what a flagellar protein's loss looks like.
      The same human study also reports acrosomal localisation, which GOA does not capture; see
      suggested_questions rather than a proposed annotation here, since it rests on one study's
      immunofluorescence.
    action: ACCEPT
    reason: >-
      Ortholog IDA at the identical term, independently reproduced by immunofluorescence in
      human spermatogenic cells.
    proposed_replacement_terms: []
    supported_by:
    - reference_id: PMID:41834962
      supporting_text: >-
        ADGB was found to be highly expressed after puberty in both human and mouse testes and
        was localized to the acrosome and flagella of spermatogenic cells.
    - reference_id: PMID:35700329
      supporting_text: >-
        it locates to the sperm flagellum, the annulus, and the midpiece, and that it is crucial
        for male fertility and sperm formation
- term:
    id: GO:0097225
    label: sperm midpiece
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  qualifier: located_in
  supporting_entities:
  - UniProtKB:G3UZ78
  - ensembl:ENSMUSP00000134378
  review:
    summary: >-
      Accepted, and it duplicates the IBA row for the same term by a second pipeline from the
      same donor and paper. The donor's own evidence is an IDA at this exact term. The human
      ultrastructural phenotype is consistent - a disorganised mitochondrial sheath is a
      midpiece defect - though that is phenotype rather than localisation and does not by itself
      establish the component.
    action: ACCEPT
    reason: Ortholog IDA at the identical term; duplicate of the IBA row by a second pipeline.
    proposed_replacement_terms: []
    supported_by:
    - reference_id: file:human/ADGB/ADGB-uniprot.txt
      supporting_text: along the whole sperm flagellum. Detected in the annulus of the sperm
- term:
    id: GO:0097227
    label: sperm annulus
  evidence_type: IEA
  original_reference_id: GO_REF:0000107
  qualifier: located_in
  supporting_entities:
  - UniProtKB:G3UZ78
  - ensembl:ENSMUSP00000134378
  review:
    summary: >-
      Accepted, duplicating the IBA row for the same term. The donor carries an IDA at this
      term, and the annulus is the location with the strongest mechanistic support: ADGB and
      SEPT10 co-localise there in stage-15 spermatids and mature sperm, and SEPT10 mislocalises
      when Adgb is lost. Septins are the structural constituents of the sperm annulus, so an
      ADGB-septin interaction at that site coheres with everything else known about the gene.
    action: ACCEPT
    reason: >-
      Ortholog IDA at the identical term, with an interaction partner and a loss-of-function
      mislocalisation phenotype both anchored at this same structure.
    proposed_replacement_terms: []
    supported_by:
    - reference_id: file:human/ADGB/ADGB-uniprot.txt
      supporting_text: along the whole sperm flagellum. Detected in the annulus of the sperm
    - reference_id: PMID:35700329
      supporting_text: >-
        Finally, in vitro data suggest that Adgb contributes to Sept10 proteolysis in a
        CaM-dependent manner.
- term:
    id: GO:0005516
    label: calmodulin binding
  evidence_type: IPI
  original_reference_id: PMID:36995441
  qualifier: enables
  supporting_entities:
  - UniProtKB:P0DP23
  review:
    summary: >-
      Proposed new annotation, and the clearest gap in this gene's record: GOA carries no
      calmodulin-binding annotation for ADGB in either human or mouse, despite calmodulin being
      the one partner that binds a defined, named motif in the protein and the one whose
      disruption is directly tied to human disease. UniProt annotates an IQ calmodulin-binding
      motif at residues 906-935, sitting between the two halves of the circularly permuted
      globin domain - an arrangement that is the structural signature of the whole protein
      family. Four independent lines support the interaction. In human patients, ADGB variants
      causing asthenozoospermia disrupt binding of ADGB to calmodulin, and UniProt records this
      with ECO:0000269 against the human entry. In cells, a truncated construct covering the
      globin and IQ domains co-immunoprecipitates calmodulin robustly, and mass spectrometry of
      the isolated globin-domain pulldown shows prominent enrichment of endogenous calmodulin.
      Biophysically, fluorescein-labelled calmodulin mutants show a 35 percent quenching with
      the N-lobe label against 10 percent with the C-lobe label on adding the purified ADGB
      globin domain, consistent with energy transfer to the heme. Functionally, calmodulin
      binding raises the domain's nitrite reductase catalytic efficiency roughly two-fold, and
      deleting the IQ motif abolishes that activation. Recorded as IPI against the human
      patient-variant study, with calmodulin-1 as the supporting entity. Note the one negative
      in the record, kept in view rather than suppressed: co-immunoprecipitation of full-length
      ADGB did not detect calmodulin under basal conditions in HEK293 cells, which the authors
      attribute to interference from the long C-terminal region. That argues the interaction is
      regulated or conformationally gated, not that it is absent.
    action: NEW
    reason: >-
      Fills the most conspicuous molecular-function gap in the record. ADGB has a
      UniProt-annotated IQ motif, human disease variants that disrupt calmodulin binding,
      direct co-immunoprecipitation and mass-spectrometric evidence, biophysical binding data
      on the purified human domain, and a measured functional consequence - yet no GO
      annotation in either species.
    proposed_replacement_terms: []
    supported_by:
    - reference_id: PMID:36995441
      supporting_text: The variants disrupted the binding of ADGB to calmodulin.
    - reference_id: PMID:35700329
      supporting_text: >-
        a truncated construct covering the globin and IQ domains displayed robust ADGB-CaM
        interaction
    - reference_id: PMID:39719941
      supporting_text: >-
        The circularly permutated globin domain of Adgb was well folded with a heme group, which
        can interact with CaM via the IQ motif.
- term:
    id: GO:0070026
    label: nitric oxide binding
  evidence_type: IDA
  original_reference_id: PMID:38725499
  qualifier: enables
  review:
    summary: >-
      Proposed new annotation. The purified human androglobin globin domain binds nitric oxide,
      and does so in a way that is unusual enough to be diagnostic rather than generic globin
      chemistry: the complex is five-coordinate, which in the globin superfamily is highly
      atypical and is instead the signature of hemoproteins with nitric-oxide storage or
      sensing roles such as soluble guanylate cyclase and cytochrome c prime. The
      characterisation used optical spectroscopy, EPR, stopped-flow and femtosecond laser flash
      photolysis; the NO-bound Soret peak is blue-shifted to 395 nm against the 420-430 nm
      typical of hexacoordinate ferrous-NO globins, and the measured affinity is in the 10^-10
      to 10^-11 M range. Adding NO to the ferric protein produced no optical change, so the
      binding is specific to the ferrous state rather than a general heme artefact. The term
      is well precedented for this chemistry. GOA annotates GUCY1B1 to GO:0070026 by IEA -
      the code is stated because the neighbouring holders are experimental and it must not be
      read across - and soluble guanylate cyclase is precisely the five-coordinate NO
      hemoprotein the authors name as ADGB's comparator, alongside cytochrome c prime. The
      experimental precedent comes from CBS, THAP4 (nitrobindin) and the haemoglobin complex
      CPX-2158, which hold the term by IDA. This is a
      molecular function of ADGB that GOA does not record at all, and unlike the oxygen term it
      is the activity the biophysics actually points to. Stated caveat: the measurements are on
      the isolated recombinant globin domain, not full-length androglobin, and no in vivo
      NO-related phenotype has been demonstrated for ADGB in any organism.
    action: NEW
    reason: >-
      Direct, multi-method biophysical demonstration on the purified human globin domain of an
      atypical five-coordinate NO complex with sub-nanomolar affinity. Not represented anywhere
      in GOA for this gene.
    proposed_replacement_terms: []
    supported_by:
    - reference_id: PMID:38725499
      supporting_text: Adgb binds NO as a five-coordinate heme iron
    - reference_id: PMID:38725499
      supporting_text: >-
        With rapid autoxidation and high nitrite reductase activity, the globin appears to be
        more tailored toward nitric oxide homeostasis or buffering.
- term:
    id: GO:0098809
    label: nitrite reductase activity
  evidence_type: IDA
  original_reference_id: PMID:38725499
  qualifier: enables
  review:
    summary: >-
      Proposed new annotation. Two independent laboratories have measured nitrite reductase
      activity on the purified human androglobin globin domain, and a third study has probed it
      by mutagenesis. The ferrous heme reacts with nitrite to generate nitric oxide, followed
      spectroscopically as loss of the 423 nm Soret with a rise near 386 nm; the kinetics fit
      Michaelis-Menten, giving kcat/KM of 0.046 mM^-1 s^-1 for the domain alone rising to 0.102
      on calmodulin binding, and mutating the distal glutamine to tyrosine further enhances the
      activity. The activity is also modulated by the redox state of the CD-loop disulfide.
      Term choice was checked against the definitions rather than the labels. GO:0050421
      "nitrite reductase (NO-forming) activity" was considered and rejected: its definition is
      cytochrome-c-specific, describing the cd1-type enzyme, and does not describe a
      deoxyferrous globin reducing nitrite. GO:0098809 is the correct level, and that is
      confirmed by curator practice rather than only by reading the definitions: GOA already
      annotates human neuroglobin, cytoglobin and myoglobin to GO:0098809 by IDA for exactly
      this chemistry, and none of the three uses the GO:0050421 child. Stated caveats,
      which are the authors' own. All measurements are on the isolated recombinant globin
      domain rather than full-length androglobin, they use dithionite as the reductant, and the
      KM values are in the millimolar range - well above physiological nitrite. The original
      authors write that it remains unclear whether this is a natural function of Adgb. It is
      proposed here as a demonstrated in vitro activity, not as an established physiological
      role, and it is not listed among the core functions for that reason.
    action: NEW
    reason: >-
      Replicated in vitro catalytic activity on the human protein's globin domain, measured by
      two independent groups with full Michaelis-Menten kinetics and probed by mutagenesis by a
      third. Absent from GOA. Proposed with the isolated-domain and millimolar-KM caveats
      explicit.
    proposed_replacement_terms: []
    supported_by:
    - reference_id: PMID:38725499
      supporting_text: >-
        With rapid autoxidation and high nitrite reductase activity, the globin appears to be
        more tailored toward nitric oxide homeostasis or buffering.
    - reference_id: PMID:39719941
      supporting_text: the binding of CaM enhanced the nitrite reductase activity of Adgb
    - reference_id: PMID:39719941
      supporting_text: it remains unclear whether this is a natural function of Adgb
core_functions:
- description: >-
    Heme-binding circularly permuted globin domain that coordinates a b-type heme through a
    retained proximal histidine (His824), with a glutamine rather than the canonical histidine
    at the distal position (Gln792). The resulting His/Gln hexacoordinate heme binds nitric
    oxide as an atypical five-coordinate complex and reduces nitrite to nitric oxide, while
    binding oxygen only transiently. This is the module that defines androglobin as a globin.
  molecular_function:
    id: GO:0020037
    label: heme binding
  locations:
  - id: GO:0036126
    label: sperm flagellum
  supported_by:
  - reference_id: PMID:22115833
    supporting_text: >-
      The recombinantly expressed human globin domain exhibits an absorption spectrum
      characteristic of hexacoordination of the heme iron atom.
  - reference_id: file:human/ADGB/ADGB-bioinformatics/RESULTS.md
    supporting_text: >-
      Verdict: the globin domain is intact as a heme protein, but it is a His/Gln
      hexacoordinate globin, not a bis-histidyl one.
  - reference_id: PMID:38725499
    supporting_text: X = His for Cygb and Gln for Adgb
- description: >-
    Calcium-sensor coupling through an IQ motif that lies between the two halves of the split
    globin domain. Calmodulin binding places its N-lobe adjacent to the heme pocket and
    increases the domain's nitrite reductase efficiency about two-fold; deleting the IQ motif
    abolishes that activation. In human patients, variants that disrupt calmodulin binding
    cause asthenozoospermia, making this the molecular function most directly tied to disease.
  molecular_function:
    id: GO:0005516
    label: calmodulin binding
  locations:
  - id: GO:0097227
    label: sperm annulus
  supported_by:
  - reference_id: PMID:36995441
    supporting_text: The variants disrupted the binding of ADGB to calmodulin.
  - reference_id: PMID:39719941
    supporting_text: the binding of CaM enhanced the nitrite reductase activity of Adgb
  - reference_id: PMID:35700329
    supporting_text: >-
      a truncated construct covering the globin and IQ domains displayed robust ADGB-CaM
      interaction
- description: >-
    Required for the late, post-meiotic remodelling of spermatids into functional spermatozoa.
    Androglobin localises to the flagellum, midpiece and annulus of elongating spermatids and
    binds septin 10, CFAP69, SPEF2, TTC29 and CFAP47; its loss in mice causes infertility with
    abnormal head shaping and defective manchette, annulus and flagellum organisation, and
    bi-allelic human variants cause asthenozoospermia and oligoasthenoteratozoospermia. The
    molecular activity underlying this requirement is not established - notably, the
    calpain-like region is a non-catalytic pseudoprotease - so this is recorded as a cellular
    role rather than as a molecular function.
  directly_involved_in:
  - id: GO:0007286
    label: spermatid development
  locations:
  - id: GO:0097225
    label: sperm midpiece
  - id: GO:0097227
    label: sperm annulus
  - id: GO:0031514
    label: motile cilium
  supported_by:
  - reference_id: PMID:35700329
    supporting_text: >-
      it locates to the sperm flagellum, the annulus, and the midpiece, and that it is crucial
      for male fertility and sperm formation
  - reference_id: PMID:38385883
    supporting_text: >-
      the spermatozoa from patients harboring ADGB variants showed multiple acrosome and
      flagellum malformations under light and electron microscopy
  - reference_id: PMID:41834962
    supporting_text: >-
      Co-immunoprecipitation experiments confirmed TTC29 and CFAP47 as interacting proteins of
      ADGB.
- description: >-
    Nitric oxide handling at the same heme. The ferrous globin domain binds nitric oxide as a
    five-coordinate complex with sub-nanomolar affinity - unusual in the globin superfamily, and
    characteristic instead of NO-storage or NO-sensing hemoproteins such as soluble guanylate
    cyclase. The same heme also reduces nitrite to nitric oxide in the isolated globin domain,
    at millimolar K_M and so of untested physiological significance, an activity that calmodulin
    binding at the IQ motif enhances about two-fold. Recorded as a core function because it is
    what the heme measurably does, whereas heme binding records only that the cofactor is
    present; the nitric oxide binding is the better-founded half of that chemistry, at
    sub-nanomolar affinity. The qualifier is stated rather than buried: every measurement is on
    the isolated recombinant globin domain, and no nitric-oxide-dependent phenotype has been
    demonstrated for androglobin in any organism.
  molecular_function:
    id: GO:0070026
    label: nitric oxide binding
  locations:
  - id: GO:0036126
    label: sperm flagellum
  supported_by:
  - reference_id: PMID:38725499
    supporting_text: Adgb binds NO as a five-coordinate heme iron
  - reference_id: PMID:38725499
    supporting_text: >-
      With rapid autoxidation and high nitrite reductase activity, the globin appears to be
      more tailored toward nitric oxide homeostasis or buffering.
  - reference_id: PMID:39719941
    supporting_text: the binding of CaM enhanced the nitrite reductase activity of Adgb
suggested_questions:
- question: >-
    UniProt's FUNCTION line for Q8N7X0 describes androglobin as a "chimeric globin with a
    bis-histidyl six-coordinate heme-iron atom", but bis-histidyl requires two histidines and
    UniProt's own feature table annotates the distal heme-iron ligand as Gln792, with only the
    proximal His824 being a histidine. Three primary papers agree the distal residue is a
    glutamine - Reeder et al. give the ferric coordination as His-Fe(III)-X with "X = His for
    Cygb and Gln for Adgb", Nie et al. label it the distal Gln30 in their construct numbering,
    and Ren et al. name it in their title and mutate it as Q12H/Q12Y. Should the FUNCTION text
    be corrected to His/Gln hexacoordinate? The prose appears to predate the 2024-2026
    biophysics.
  experts:
  - UniProt curation team
  - David Hoogewijs
  - Brandon Reeder
- question: >-
    Human ADGB carries no experimental GO annotation of any kind, despite Evidence at protein
    level and more than a decade of published human biochemistry: heme binding by the human
    recombinant globin domain, nitric-oxide and nitrite chemistry on that domain by two
    independent laboratories, calmodulin binding demonstrated biophysically and disrupted by
    human disease variants, and co-immunoprecipitation of CFAP69, SPEF2, TTC29 and CFAP47 with
    human ADGB. All 13 current rows are electronic or phylogenetic, and 8 of them trace to a
    single mouse ortholog and two papers. Could GOA curate the human primary literature
    directly rather than relying on Compara and PAINT transfer?
  experts:
  - GOA curation team
  - UniProt curation team
- question: >-
    Is androglobin itself the protease in the SEPT10 cleavage reaction? MEROPS classifies ADGB
    as a non-peptidase homologue of family C2 with ADGB as the holotype, UniProt flags the loss
    of active-site residues in a CAUTION, and alignment against six reviewed calpains under
    four substitution models finds the catalytic histidine and asparagine absent while only the
    nucleophile cysteine (C132) is retained. The cleavage evidence comes from co-overexpression
    of both proteins in HEK293 cells with whole-domain deletions, not from a purified-protein
    assay or a catalytic-residue point mutant. An equally consistent model is that androglobin
    targets SEPT10 to a different protease in a calmodulin-dependent manner.
  experts:
  - Anna Keppner
  - David Hoogewijs
  - MEROPS curation team
- question: >-
    Should GO:0001669 acrosomal vesicle be annotated for ADGB? Immunofluorescence in human and
    mouse spermatogenic cells reports androglobin at the acrosome as well as the flagella, and
    human patients with bi-allelic ADGB variants show acrosome loss by electron microscopy. It
    is not proposed as an annotation here because the localisation rests on a single study, but
    it is the most likely missing cellular component if it can be independently confirmed.
  experts:
  - GOA curation team
- question: >-
    Is the nitrite reductase activity physiologically relevant, or an in vitro property of the
    isolated domain? All measurements use the recombinant globin domain with dithionite as
    reductant and millimolar KM values; the original authors write that it remains unclear
    whether this is a natural function. Against that, testicular oxygen tension is low
    (~10-15 mmHg), which is the regime where globin nitrite reductase activity is thought to
    matter, and androglobin is expressed in exactly those post-meiotic cells.
  experts:
  - Brandon Reeder
  - Ying-Wu Lin
- question: >-
    A PAINT-specific observation: within PANTHER PTHR46298, the biological-process term
    GO:0007286 sits at node PTN002922608 while the two cellular-component terms sit at
    PTN002922607. The family's reviewed membership is only human and mouse androglobin, so no
    harm results here, but it is worth confirming the two-node split is intentional rather than
    an artefact, since androglobin orthologs exist across 3237 taxa and any future expansion of
    the reviewed set would inherit whichever placement is wrong.
  experts:
  - GO Reference Genome/PAINT curators
suggested_experiments:
- hypothesis: >-
    Androglobin does not itself hydrolyse peptide bonds; the SEPT10 fragment observed on
    co-overexpression is produced by a cellular protease that androglobin recruits or licenses
    in a calmodulin-dependent manner.
  description: >-
    Express and purify the isolated ADGB calpain-like region (residues 70-411) and full-length
    androglobin, and assay them directly against recombinant SEPT10 in the presence and absence
    of calcium and calmodulin. Include a C132S substitution as the catalytic-residue control -
    the point mutant that the existing cell-based work never made - and a panel of
    class-specific protease inhibitors. In parallel, repeat the HEK293 co-overexpression
    experiment with the C132S full-length protein: if the 37 kDa SEPT10 band still appears,
    androglobin is not the catalyst, and the whole-domain deletion result reflects loss of a
    binding or scaffolding function rather than of catalysis.
  experiment_type: in vitro reconstitution and structure-function
- hypothesis: >-
    The extreme autoxidation rate measured for the isolated globin domain is a property of the
    truncated construct, and the full-length protein or the calmodulin-bound complex stabilises
    the oxy form enough for oxygen chemistry to be physiologically accessible.
  description: >-
    Measure oxygen association and dissociation kinetics and the autoxidation rate on
    full-length androglobin, and on the globin domain in complex with calcium-loaded
    calmodulin, by stopped-flow and flash photolysis, comparing directly against the published
    isolated-domain values. Repeat with the Q792H variant, which restores the canonical distal
    histidine and has already been shown to improve stability, to test whether the distal
    glutamine is what destabilises the oxy complex.
  experiment_type: biophysical kinetics
- hypothesis: >-
    The distal glutamine is functionally required in vivo, and androglobin's role in spermatid
    maturation depends on its heme chemistry rather than only on its scaffolding interactions.
  description: >-
    Generate Adgb knock-in mice carrying the Q792H equivalent (restoring the ancestral distal
    histidine) and, separately, a proximal H824A heme-binding-null allele, and compare sperm
    counts, motility, annulus and manchette organisation and axonemal ultrastructure against
    wild-type and full knockout. A heme-null allele that phenocopies the knockout would
    establish that the globin chemistry, not merely the protein's presence, is what spermatid
    development requires; a heme-null allele with a normal phenotype would show the reverse and
    would reframe androglobin as a cytoskeletal adaptor that happens to carry a heme.
  experiment_type: mouse genetics
- hypothesis: >-
    Androglobin generates nitric oxide from nitrite in post-meiotic germ cells under the low
    oxygen tension of the testis.
  description: >-
    Quantify nitric oxide output in wild-type versus Adgb-null spermatids using a cell-permeant
    NO probe under controlled oxygen tensions spanning the testicular range, with and without
    nitrite supplementation, and confirm by measuring downstream nitrosation. Complement with
    quantitative proteomics of S-nitrosylated targets in wild-type versus knockout testis to
    identify whether any of the known androglobin partners - septin 10, CFAP69, SPEF2, TTC29,
    CFAP47 - are among them, which would connect the heme chemistry to the cytoskeletal
    phenotype.
  experiment_type: cell biology and redox proteomics
references:
- id: GO_REF:0000002
  title: Gene Ontology annotation through association of InterPro records with GO
    terms
  findings: []
- id: GO_REF:0000033
  title: Annotation inferences using phylogenetic trees
  findings: []
- id: GO_REF:0000044
  title: Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location
    vocabulary mapping, accompanied by conservative changes to GO terms applied by
    UniProt
  findings: []
- id: GO_REF:0000107
  title: Automatic transfer of experimentally verified manual GO annotation data to
    orthologs using Ensembl Compara
  findings: []
- id: PMID:22115833
  title: 'Androglobin: a chimeric globin in metazoans that is preferentially expressed
    in Mammalian testes.'
  full_text_unavailable: true
  findings:
  - statement: >-
      The human androglobin globin domain was recombinantly expressed and shows an absorption
      spectrum characteristic of hexacoordinate heme iron, establishing heme binding for the
      human protein directly rather than by inference from the family.
    supporting_text: >-
      The recombinantly expressed human globin domain exhibits an absorption spectrum
      characteristic of hexacoordination of the heme iron atom.
  - statement: >-
      The N-terminal region is homologous to the catalytic domain II of human calpain-7, which
      is the origin of the InterPro IPR001300 match and hence of the two proteolysis-related
      IEA rows.
    supporting_text: >-
      The calpain-like region is homologous to the catalytic domain II of the large subunit of
      human calpain-7.
  - statement: >-
      The globin domain is a genuine myoglobin-like fold that has been rearranged and split,
      which is why the two halves receive separate UniProt Domain features.
    supporting_text: >-
      The globin domain satisfies the criteria of a myoglobin-like fold but is rearranged and
      split into two parts.
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: >-
      The founding androglobin paper and the source UniProt cites for the domain architecture,
      the heme binding and, via ECO:0000305, the CAUTION about the missing calpain active-site
      residues. PubMed-verified; no retraction, erratum or Crossref-only corrigendum. Only the
      abstract is cached, so nothing here rests on unread full text.
- id: PMID:38725499
  title: The circularly permuted globin domain of androglobin exhibits atypical heme
    stabilization and nitric oxide interaction.
  findings:
  - statement: >-
      Oxygen binding by the androglobin globin domain is demonstrable but transient, and the
      authors conclude from the autoxidation rate that it is not a physiological function. This
      is the evidence behind keeping GO:0019825 as non-core and behind not proposing GO:0005344
      oxygen carrier activity or GO:0019826 oxygen sensor activity.
    supporting_text: >-
      This remarkable autoxidation rate strongly suggests that O2 binding is not a physiological
      function of the protein except for the possibility of oxygen sensing.
  - statement: >-
      The measured chemistry points to nitric oxide handling rather than oxygen, which is the
      basis for the two proposed NEW molecular-function annotations.
    supporting_text: >-
      With rapid autoxidation and high nitrite reductase activity, the globin appears to be
      more tailored toward nitric oxide homeostasis or buffering.
  - statement: >-
      Androglobin binds nitric oxide as a five-coordinate complex, which is highly unusual
      among globins and characteristic of nitric-oxide storage hemoproteins.
    supporting_text: Adgb binds NO as a five-coordinate heme iron
  - statement: >-
      The distal heme-iron ligand of androglobin is a glutamine, not a histidine, stated
      explicitly in contrast with cytoglobin. This contradicts UniProt's bis-histidyl FUNCTION
      text and agrees with UniProt's own feature table.
    supporting_text: X = His for Cygb and Gln for Adgb
  - statement: >-
      A tyrosine replaces the otherwise invariant CD1 phenylalanine, a further departure from
      canonical eukaryotic globin architecture that affects heme stabilisation.
    supporting_text: >-
      Exceptional for eukaryotic globins is that a tyrosine takes the place of the highly
      conserved phenylalanine in the CD1 position, a critical point in stabilizing the heme.
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: >-
      The only full biophysical characterisation of the androglobin globin domain, and the
      single most important reference for this review's molecular-function calls. Notably it
      was NOT in the affinage record and was found by an independent PubMed sweep; without it
      the oxygen-binding row had no experimental anchor in either direction and the
      distal-glutamine finding was invisible. Full text cached and read, including the
      paragraphs surrounding each quotation. PubMed-verified; no retraction, erratum or
      Crossref-only corrigendum.
- id: PMID:39719941
  title: Calmodulin interacts with androglobin and regulates the nitrite reductase activity.
  findings:
  - statement: >-
      Calmodulin binding at the IQ motif increases the nitrite reductase catalytic efficiency
      of the androglobin globin domain roughly two-fold, linking the calcium-sensor module
      directly to the heme chemistry.
    supporting_text: the binding of CaM enhanced the nitrite reductase activity of Adgb
  - statement: >-
      Independent confirmation that the distal heme ligand is a glutamine and the proximal
      ligand a histidine, in a construct whose numbering maps onto UniProt Q792 and H824.
    supporting_text: >-
      These observations suggest that Gln30 in the heme distal site may coordinate to the heme
      iron in the ferrous state.
  - statement: >-
      The circularly permuted globin domain folds correctly with heme and engages calmodulin
      through the IQ motif, supporting both the heme-binding and the proposed
      calmodulin-binding annotations.
    supporting_text: >-
      The circularly permutated globin domain of Adgb was well folded with a heme group, which
      can interact with CaM via the IQ motif.
  - statement: >-
      The authors themselves qualify whether nitrite reduction is a natural function of
      androglobin, which is recorded as an explicit caveat on the proposed GO:0098809
      annotation.
    supporting_text: it remains unclear whether this is a natural function of Adgb
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: >-
      Full text cached and read. One internal inconsistency worth flagging for anyone quoting
      it: the Results body text says "Asn30 in helix E is located in the heme distal position",
      while the Fig. 1B legend and the concluding sentence of that same paragraph both say
      Gln30. The Swiss-Prot sequence settles it - UniProt position 792, which the register
      arithmetic maps to their residue 30, is a glutamine. Quoting the body sentence alone
      would have propagated a typographical error, so only the legend-consistent statements are
      used here. PubMed-verified; no retraction or erratum.
- id: PMID:42372363
  title: Spectroscopic studies on human androglobin regulated by its heme distal Gln12
    and IQ motif via interaction with calmodulin.
  full_text_unavailable: true
  findings:
  - statement: >-
      A third independent confirmation that the heme distal residue of human androglobin is a
      glutamine, here established by mutagenesis rather than by inference - the authors
      generate Q12H and Q12Y substitutions and show that the distal residue controls both
      stability and nitrite reductase activity, and that deleting the IQ motif abolishes
      calmodulin-mediated activation.
    supporting_text: >-
      investigated the role of its heme distal residue Gln12 through the generation of Q12H and
      Q12Y mutants
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: >-
      Abstract only. Also absent from the affinage record and found by independent PubMed
      search. Its value here is that it converts the distal-glutamine claim from an alignment
      and spectroscopy inference into a mutational one, and it independently supports the IQ
      motif being required for calmodulin-dependent activation. Its construct numbering
      (Gln12, C114S/C190S) differs from both UniProt's and Nie et al.'s, so no positional claim
      is transferred from it without the register being checked. PubMed-verified; the Crossref
      lookup for its DOI returned 404, which is recorded rather than treated as a clean result.
- id: PMID:35700329
  title: Androglobin, a chimeric mammalian globin, is required for male fertility.
  findings:
  - statement: >-
      Adgb-null mice are infertile and androglobin localises to the sperm flagellum, annulus
      and midpiece. This is the source of the mouse IDA annotations that both the PAINT IBA
      rows and the Ensembl Compara rows on human ADGB are transferred from.
    supporting_text: >-
      it locates to the sperm flagellum, the annulus, and the midpiece, and that it is crucial
      for male fertility and sperm formation
  - statement: >-
      The proteolysis claim is stated by the authors as a suggestion from in vitro data about
      overexpressed proteins, not as a demonstration that androglobin catalyses the cleavage.
      This is the wording the MARK_AS_OVER_ANNOTATED call on GO:0006508 rests on.
    supporting_text: >-
      Collectively, these in vitro data suggest a scenario in which overexpressed ADGB
      proteolytically contributes to cleavage of overexpressed SEPT10 in an O2-independent but
      CaM-dependent manner.
  - statement: >-
      A construct spanning the globin and IQ domains binds calmodulin robustly by
      co-immunoprecipitation, whereas full-length androglobin did not under basal conditions,
      suggesting the interaction is conformationally gated by the long C-terminal region.
    supporting_text: >-
      a truncated construct covering the globin and IQ domains displayed robust ADGB-CaM
      interaction
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: >-
      The principal in vivo study and the donor of most of this gene's transferred annotations.
      Full text cached and read rather than relied on at abstract level, which mattered: the
      abstract's "Adgb contributes to Sept10 proteolysis" reads far more strongly than the
      Results, where the assay is co-overexpression in HEK293 cells with whole-domain deletions
      and no catalytic-residue mutant. Checked for the complex-projection pattern - the
      reference annotates only two distinct entities and its phenotype terms stay on Adgb alone
      - so it is parallel per-protein curation, not a projection. PubMed-verified; no
      retraction or erratum.
- id: PMID:36995441
  title: ADGB variants cause asthenozoospermia and male infertility.
  full_text_unavailable: true
  findings:
  - statement: >-
      Human ADGB variants causing asthenozoospermia disrupt binding of androglobin to
      calmodulin. This is the human-specific evidence behind the proposed GO:0005516
      annotation, and UniProt records the same interaction with ECO:0000269 against the human
      entry.
    supporting_text: The variants disrupted the binding of ADGB to calmodulin.
  - statement: >-
      CFAP69 and SPEF2 were confirmed as androglobin-binding proteins, connecting androglobin
      to the ciliary and flagellar assembly machinery.
    supporting_text: In particular, CFAP69 and SPEF2 were confirmed to bind to ADGB.
  - statement: >-
      Adgb-null mice show abnormal spermatogenesis with malformation of elongating and
      elongated spermatids, the IMP that both the GO:0007286 IBA and Compara rows derive from.
    supporting_text: >-
      Spermatogenesis was also abnormal, with malformation of both elongating and elongated
      spermatids
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: >-
      Abstract only in the cache, but this is the reference UniProt cites with ECO:0000269 for
      the human FUNCTION, the asthenozoospermia disease link, the truncating variant and the
      calmodulin interaction, so the human-specific claims used here are independently anchored
      in the curated entry rather than resting on my reading of the abstract alone.
      PubMed-verified; no retraction or erratum.
- id: PMID:38385883
  title: 'Whole-exome sequencing identifies ADGB as a novel causative gene for male
    infertility in humans: from motility to fertilization.'
  full_text_unavailable: true
  findings:
  - statement: >-
      Bi-allelic ADGB variants in three unrelated Han Chinese men cause severe
      asthenoteratozoospermia with acrosome and flagellum malformations on light and electron
      microscopy, providing human loss-of-function corroboration for the spermatogenesis and
      flagellum annotations transferred from mouse.
    supporting_text: >-
      the spermatozoa from patients harboring ADGB variants showed multiple acrosome and
      flagellum malformations under light and electron microscopy
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: >-
      Second independent human genetics cohort. Used only for the human phenotype, deliberately
      not for any molecular-function claim, since a knockout or loss-of-function phenotype does
      not by itself establish a molecular activity. PubMed-verified; no retraction or erratum.
- id: PMID:41834962
  title: '[Whole Exome Sequencing Identified Novel Pathogenic Mutations of ADGB in Patients
    With Oligoasthenozoospermia].'
  findings:
  - statement: >-
      Immunofluorescence places androglobin in the acrosome and flagella of human and mouse
      spermatogenic cells, with expression rising after puberty. The flagellar localisation
      corroborates the transferred GO:0036126 annotation directly in human; the acrosomal
      localisation is not currently captured by GOA and is raised as a question rather than
      proposed, since it rests on this single study.
    supporting_text: >-
      ADGB was found to be highly expressed after puberty in both human and mouse testes and
      was localized to the acrosome and flagella of spermatogenic cells.
  - statement: >-
      TTC29 and CFAP47 were confirmed as androglobin interactors by co-immunoprecipitation,
      extending the set of ciliary and flagellar partners beyond septin 10, CFAP69 and SPEF2.
    supporting_text: >-
      Co-immunoprecipitation experiments confirmed TTC29 and CFAP47 as interacting proteins of
      ADGB.
  reference_review:
    relevance: MEDIUM
    correctness: VERIFIED
    review_notes: >-
      Third independent human genetics cohort, 781 men, published in Chinese with an English
      abstract; the cached record is bilingual and the English text is abstract-level. Treated
      accordingly - used for the human localisation and interactor claims that the abstract
      states explicitly, and not leaned on for anything requiring the figures. PubMed-verified
      against the correct DOI (10.12182/20260160108); the Crossref update lookup returned 404
      for that DOI, which is reported rather than counted as a clean pass.
- id: PMID:34083607
  title: Composition and function of the C1b/C1f region in the ciliary central apparatus.
  findings:
  - statement: >-
      Androglobin is a component of the C1b/C1f supercomplex of the ciliary central apparatus
      in Tetrahymena, alongside Spef2A and Cfap69 - the same proteins that were later found to
      bind androglobin in mammals. This supports the motile-cilium localisation outside the
      sperm context.
    supporting_text: >-
      C1b/C1f contains several evolutionarily conserved proteins: Spef2A, Cfap69,
      Cfap246/LRGUK, Adgb/androglobin
  - statement: >-
      Deleting Adgb caused only minor changes in ciliary motility, unlike deletion of Spef2A or
      Cfap69 which abolished the entire C1b projection. Androglobin is therefore a resident of
      the structure rather than a core structural or motor component, which is consistent with
      annotating localisation but not a motility function.
    supporting_text: Loss of either Cfap246 or Adgb caused only minor alterations in ciliary motility.
  reference_review:
    relevance: MEDIUM
    correctness: VERIFIED
    review_notes: >-
      Tetrahymena, not human, so it is used as convergent support for the motile-cilium
      component and deliberately not as evidence for any human-specific claim. Its negative
      result - minor motility change on Adgb deletion - is recorded as well as its positive
      one, because it constrains how strongly the ciliary role should be stated. Full text
      cached. PubMed-verified; no retraction or erratum.
- id: PMID:33453283
  title: Androglobin gene expression patterns and FOXJ1-dependent regulation indicate its
    functional association with ciliogenesis.
  findings:
  - statement: >-
      Across human tissues, ADGB expression is specifically associated with motile-ciliated
      cell types beyond the testis, including the female reproductive tract, lung and brain,
      supporting the motile-cilium annotation as more than a sperm-flagellum artefact.
    supporting_text: specifically being associated with cell types forming motile cilia
  - statement: >-
      Overexpressing full-length ADGB increases the number of ciliated cells, and the ADGB
      promoter is a direct target of the ciliogenic transcription factors FOXJ1 and RFX2.
    supporting_text: >-
      cell culture studies indicated an ADGB-dependent increase in the number of ciliated cells
      upon overexpression of the full-length protein, confirming a ciliogenesis-associated role
      of ADGB in mammals
  reference_review:
    relevance: HIGH
    correctness: VERIFIED
    review_notes: >-
      The primary FOXJ1/ciliogenesis paper. Absent from the affinage record, which cited the
      later secondary FOXJ1 paper PMID:37158461 instead; found by independent PubMed search.
      Full text cached. PubMed-verified; no retraction or erratum.
- id: PMID:37158461
  title: Congenital heart defects caused by FOXJ1.
  full_text_unavailable: true
  findings: []
  reference_review:
    relevance: LOW
    correctness: VERIFIED
    review_notes: >-
      Cited by the affinage record for FOXJ1 activating the ADGB promoter, but the paper is
      about FOXJ1-associated congenital heart defects and uses the ADGB promoter as a reporter
      readout for FOXJ1 function rather than studying ADGB. Retained for completeness and
      marked LOW relevance; the ADGB-side claim is taken from the primary source PMID:33453283
      instead. No claim in this review rests on it. PubMed-verified; no retraction or erratum.
- id: PMID:41138754
  title: Expression analysis of androglobin and its influence on the transcriptome in cancer.
  full_text_unavailable: true
  findings: []
  reference_review:
    relevance: LOW
    correctness: VERIFIED
    review_notes: >-
      Cited by the affinage record for RFX3 regulation of the ADGB promoter and for
      transcriptomic effects of ADGB overexpression in A549 lung cancer cells. Both are
      transcriptional-regulation and overexpression-phenotype observations rather than evidence
      of androglobin's own function, so no annotation here rests on it. PubMed-verified; no
      retraction or erratum.

ADGB

Gene Description

Existing Annotations Review

Core Functions

References

Suggested Questions for Experts

Suggested Experiments

Deep Research

Affinage

Affinage mechanistic annotation for ADGB (human)

Current model (mechanistic narrative)

Affinage mechanism profile (its own GO/Reactome grounding)

Dated findings (citation-anchored)

Citations

📚 Additional Documentation

Notes

ADGB (androglobin, Q8N7X0) — review notes

GOA / stub reconciliation (done first, before reviewing)

Architecture: what the two domains actually are

Test 1 — is the calpain domain a protease? No.

But the mirror error is also live here — ADGB is implicated in proteolysis

Test 2 — is the globin domain a real heme protein? Yes. Is it bis-histidyl? No.

Three primary papers agree, and the register arithmetic checks out

The UniProt entry contradicts itself, and this is worth reporting upstream

Test 3 — is GO:0019825 oxygen binding wrong? No, and this is where I nearly made the mirror error.

IBA propagation: checked, and clean in both directions

Redundancy worth recording: two pipelines, one donor, two papers

The real gap: human experiments exist and none of them is curated

Cilium beyond sperm

Provider assessment (affinage)

Verdict summary

Curator-precedent survey (run to test my own term choices against GOA practice)

Checks run that came back negative (recorded so the next reviewer knows they were run)

Process notes

Round-2 note: the blocking fix was made by the maintainer, not by me

Bioinformatics Results

ADGB (Q8N7X0) - do the calpain and globin domains retain their functional residues?

Question

Q1. Calpain catalytic triad: NOT retained

Independent corroboration: MEROPS classifies ADGB as a non-peptidase homologue

Caveat that must be stated

Q2. Globin heme ligands: proximal His retained, distal His replaced by Gln

What this does and does not settle

📄 View Raw YAML

Test 3 — is `GO:0019825 oxygen binding` wrong? No, and this is where I nearly made the mirror error.