DNAAF2/KTU helps build axonemal dynein arms in the cytoplasm. Human KTU deficiency affects outer and inner arms. The discriminating Chlamydomonas experiment shows that residual heavy chain fails to associate with intermediate/light chains even though their smaller subcomplex forms. This supports performed preassembly work and a heavy-chain stability contribution, rather than assigning dynein motor activity to an assembly factor PMID:19052621(https://pubmed.ncbi.nlm.nih.gov/19052621/).
The supported core is one integrated arm-preassembly function. Human respiratory fractionation and HPA support a cytoplasmic/cytosolic pool. Tagged Xenopus Ktu occupies dynamic DynAP foci with dyneins and assembly factors; human HEATR2/LRRC6 imaging in the same study is not human DNAAF2 imaging. Cytosol and DynAP are retained as two supported pools, without exclusivity or a stable-complex interpretation PMID:23872636(https://pubmed.ncbi.nlm.nih.gov/23872636/), PMID:30561330(https://pubmed.ncbi.nlm.nih.gov/30561330/), PMID:33263282(https://pubmed.ncbi.nlm.nih.gov/33263282/), HPA DNAAF2.
Targeted DYX1C1 and PIH1D3 interaction assays are positive. DNAAF2 also associates with DYX1C1 isoform a in human-cell LUMIER and proteomics. The proposed R2SD particle remains hypothetical; the 2018 client-stabilization and liprin-alpha2 assembly assays concern PIH1D2/R2SP. Mouse Ktu–DNAI2/Hsp70 extract associations are not purified binary human reactions, and Hsp90 was negative in that assay PMID:23872636(https://pubmed.ncbi.nlm.nih.gov/23872636/), PMID:28041644(https://pubmed.ncbi.nlm.nih.gov/28041644/), PMID:29844425(https://pubmed.ncbi.nlm.nih.gov/29844425/), PMID:19052621(https://pubmed.ncbi.nlm.nih.gov/19052621/).
The imported interaction partner Q7Z6J8 is UBE3D. Its positive associations are represented by a 2016 TAP spoke, 2021 BioPlex records and the 2025 primary U2OS graph edge 608480. These data do not establish DNAAF2 ubiquitination or a specific ligase-recognition mechanism. Positive generic associations are retained as non-core under the scoped project instruction PMID:27173435(https://pubmed.ncbi.nlm.nih.gov/27173435/), PMID:33961781(https://pubmed.ncbi.nlm.nih.gov/33961781/), PMID:40205054(https://pubmed.ncbi.nlm.nih.gov/40205054/).
The imported CFAP300 pair cites PMID:29727692. Selected original Methods and target-name searching did not identify its binding experiment. The companion PMID:29727693 explicitly supplies the DNAAF2 yeast two-hybrid/co-immunoprecipitation evidence. The imported source identity remains unchanged and its attribution is flagged, while the independently positive interaction is retained PMID:29727692(https://pubmed.ncbi.nlm.nih.gov/29727692/), PMID:29727693(https://pubmed.ncbi.nlm.nih.gov/29727693/).
All four PAINT IBDs occur on the reconstructed human lineage; the 837-residue target sequence exactly matches its alignment row. The source list includes valid target experimental grounding. Mouse and zebrafish donor context is preserved: zebrafish single ktu-mutant sperm can retain normal movement despite subtle inner-arm defects, whereas Kupffer-vesicle motility is abnormal and pih1d2/ktu double mutants show stronger defects. This context does not negate the human preassembly role PMID:23525783(https://pubmed.ncbi.nlm.nih.gov/23525783/), PMID:29741156(https://pubmed.ncbi.nlm.nih.gov/29741156/). Human PIH1D1 chromatin biology is separate family context and is not transferred to DNAAF2 PMID:22368283(https://pubmed.ncbi.nlm.nih.gov/22368283/).
The official products are Q9NVR5-1, 837 residues, and Q9NVR5-2, 789 residues, whose internal deletion is canonical residues 622–669. Both sequences were independently reconstructed against official FASTAs. The respiratory Western doublet was not an accession-resolved activity test; neither equivalent activity nor inactivity is established for the natural shorter product UniProt Q9NVR5, PMID:19052621(https://pubmed.ncbi.nlm.nih.gov/19052621/).
No new annotation was added. The extracellular-location inference is rejected because the upstream process describes fluid moved by epithelial cilia, not a secreted DNAAF2 molecule. The mechanistic core omits an unestablished folding or motor molecular function and a named stable R2SD complex. Exact source locators, access limits, pair identifiers and current mapping evidence are in the source guide.
The genuine default Falcon attempt returned HTTP 403 authentication failure; the configured perplexity-lite fallback returned HTTP 401 quota failure. No provider report was created or simulated. This manual record and the source guide document the inspected primary evidence. Source caches, official sequence/annotation files and failed access receipts remain unchanged. Ordinary final validation, status derivation and HTML rendering are reserved to the canonical publisher.
The localization refinement now includes the independently recorded human basal-body pool rather than treating cytosol as exhaustive. The 2008 study separates successful medaka renal-tubule immunohistochemistry (Results on localization; Figure 1q,r) from human respiratory fractionation (Figure 2d) and the unsuccessful human respiratory-cell immunohistochemistry. Medaka Ktu is enriched in apical cytoplasm near gamma-tubulin-positive structures, but the signals usually do not colocalize. This does not establish membership in the microtubule-nucleating pericentriolar material PMID:19052621(https://pubmed.ncbi.nlm.nih.gov/19052621/).
The official HPA ICC/IF record lists both cytosol and basal body as main locations with approved reliability. HPA002894 records basal-body staining in ASC52telo, serum-starved hTERT-RPE1 and RPTEC/TERT1; its ciliated-cell records describe cilia and basal-body channels separately. These are positive human localization calls, without an independent image-pixel interpretation in this follow-up. Basal body was added to the existing broad cytoplasm replacements using that gene-level evidence. It is not reattributed to the original human fractionation, to medaka colocalization, or to a formal basal-body-to-cytoplasm ontology path: the checked path query returned none. Core locations continue to identify the assembly-associated cytosol/DynAP pools, rather than claiming an assembly function for every detected compartment HPA DNAAF2, official XML, ciliary basal body, pericentriolar material.
A short positive Hsp70 anchor now accompanies the broad chaperone-complex judgment. The actual experiment is mouse testis co-immunoprecipitation and GST-mKtu pull-down from extract (Figure 4b,d; GST pull-down and immunoprecipitation Methods), not a purified human binding or folding assay. Human DNAAF2–DYX1C1 isoform-a LUMIER and HeLa SILAC association supplies a separate positive context (2018 Figures 4b and 5b). The hypothetical R2SD qualification remains; the demonstrated PIH1D2/R2SP client assay is not assigned to DNAAF2 PMID:19052621(https://pubmed.ncbi.nlm.nih.gov/19052621/), PMID:29844425(https://pubmed.ncbi.nlm.nih.gov/29844425/).
The original CFAP300 Results and Figure S12 in PMID:29727693 show a controlled DNAAF2 Y2H and tagged co-immunoprecipitation result. UniProt independently cites that paper for the same pair. This corroboration supports the retained interaction but does not establish a transcription error in GOA's original PMID:29727692 attribution; that identifier and its source dictionary remain unchanged. Resolving the source attribution is a curation task, now kept here rather than among biological expert questions PMID:29727693(https://pubmed.ncbi.nlm.nih.gov/29727693/), UniProt Q9NVR5.
All 22 source identities, annotation actions, both natural products and the assembly core remain unchanged. The standalone description now states biology directly. The two new short quotations appear only in annotation support, totaling 15 newly reproduced words from PMID:19052621; inherited quotations and all prior notes remain intact.
The HPA basal-body observation is now represented once as a new location annotation from GO_REF:0000052 and the unchanged official HPA XML snapshot. It is removed from the three cytoplasm replacement lists, whose PAINT, respiratory-fractionation and sequence-rule sources do not make that distinct claim. The HPA record uses one antibody across three human cell models; the assembly function of this pool remains unresolved. The core continues to locate dynein assembly in cytosol and DynAPs. This supersedes the preceding placement of basal body among cytoplasm replacements.
The two natural products retain their exact identities and sequence notes. The source experiments do not resolve their separate preassembly contributions or map the respiratory Western doublet to accessions. These limits remain explicit here while the product descriptions state the biological distinctions. The curated UniProt CFAP300 statement now has its own short source anchor; the original GOA PMID is preserved.