BSCL2

Summary: The exact seipin interaction from the systematic screen remains unverified.

Reason: The original IPI assertion identifies UniProtKB:Q96HH6 (TMEM19). The cached source contains only the complete abstract; the target-specific interaction table and corresponding assay record were not available in the inspected body. General screen methods and the immutable UniProt interaction listing do not independently verify this particular source edge. Retain the assertion as unresolved, without treating the screen citation or generic term as evidence of an error.

Summary: The exact seipin interaction from the systematic screen remains unverified.

Reason: The original IPI assertion identifies UniProtKB:Q9BZL3 (SMIM3). The cached source contains only the complete abstract; the target-specific interaction table and corresponding assay record were not available in the inspected body. General screen methods and the immutable UniProt interaction listing do not independently verify this particular source edge. Retain the assertion as unresolved, without treating the screen citation or generic term as evidence of an error.

Summary: The exact seipin interaction from the systematic screen remains unverified.

Reason: The original IPI assertion identifies UniProtKB:Q96HH6 (TMEM19). The cached source contains the complete abstract plus Introduction and Discussion, despite its full_text_available flag; the target-specific interaction table and corresponding assay record were not available in the inspected body. General screen methods and the immutable UniProt interaction listing do not independently verify this particular source edge. Retain the assertion as unresolved, without treating the screen citation or generic term as evidence of an error.

Summary: The exact seipin interaction from the systematic screen remains unverified.

Reason: The original IPI assertion identifies UniProtKB:Q9BZL3 (SMIM3). The cached source contains the complete abstract plus Introduction and Discussion, despite its full_text_available flag; the target-specific interaction table and corresponding assay record were not available in the inspected body. General screen methods and the immutable UniProt interaction listing do not independently verify this particular source edge. Retain the assertion as unresolved, without treating the screen citation or generic term as evidence of an error.

Summary: Seipin associates with promethin/LDAF1 in mammalian cells.

Reason: The inspected Results directly report co-isolation of tagged human seipin with promethin in MCF7 cells, with an ER-protein negative control, and additional experiments in AML12 and HEK293 cells. Both long and short seipin forms and A212P were co-purified in the latter assay. This supports the exact Q96B96 interaction at the level of complex association; it does not establish a purified binary affinity or an isoform-exclusive function. Retain generic binding as non-core, with the lipid-droplet assembly mechanism represented in whole-gene synthesis.

Summary: The specific seipin interaction is not resolved by the available abstract.

Reason: The complete cached abstract implicates BSCL2 in fusion and expansion of DFCP1-positive nascent structures, but its explicit interaction statement concerns DFCP1 and the Rab18-ZW10 complex. It does not describe the original seipin–UniProtKB:Q9HBF4 (DFCP1/ZFYVE1) binding assay. The experimental annotation may be supported in the unread full Results or supplementary data; perturbation of the same process alone does not establish this individual physical interaction. Keep this source-specific assertion unresolved rather than removing it.

Summary: The specific seipin interaction is not resolved by the available abstract.

Reason: The complete cached abstract implicates BSCL2 in fusion and expansion of DFCP1-positive nascent structures, but its explicit interaction statement concerns DFCP1 and the Rab18-ZW10 complex. It does not describe the original seipin–UniProtKB:Q9NP72 (RAB18) binding assay. The experimental annotation may be supported in the unread full Results or supplementary data; perturbation of the same process alone does not establish this individual physical interaction. Keep this source-specific assertion unresolved rather than removing it.

Summary: Seipin forms the lipid-droplet assembly complex with LDAF1.

Reason: The inspected Results identify TMEM159/promethin (renamed LDAF1; Q96B96) by seipin co-immunoprecipitation in human SUM159 cells, verify association by immunoblotting, and isolate a recombinant LDAF1–seipin complex from mammalian cells. The seipin hydrophobic-helix deletion loses the association. Endogenously tagged proteins colocalize, and association changes during droplet maturation. This directly supports the exact partner assertion. Keep the generic binding term non-core; its mechanistic complex/assembly role belongs in the broader synthesis alongside the more informative physical activities.

Summary: Human seipin binds anionic phospholipids.

Reason: The complete PMID:30293840 abstract explicitly reports anionic-phospholipid binding by full-length human SEIPIN and its lumenal domain, including phosphatidic acid. This directly supports the molecular function and the lipid-organizing mechanism. The full binding assay conditions were not available, so affinity, exclusivity for phosphatidic acid and isoform-specific differences are not inferred.

Summary: Conserved ER membrane localization is supported by direct human observations.

Reason: The GOA assertion uses ancestral node PTN000476621. The official FlyBase seipin record independently displays this same node for ER membrane localization, but the complete PAINT IBD/tree/MSA was unavailable. Human ER membrane localization is directly supported by PMID:14981520 and the cellular localization and contact-site experiments in PMID:27879284 and PMID:31708432. There is no evidence here of human loss of this conserved localization; target self-source is legitimate experimental grounding, not circular evidence.

Summary: Seipin is an integral protein of the ER membrane.

Reason: The complete cached abstract explicitly identifies seipin as an integral ER membrane protein. The N88S/S90L glycosylation and aggregation results concern pathogenic variants and are kept distinct from wild-type localization. Full original Methods were unavailable; independent human ER localization in PMID:27879284 corroborates the compartment.

Summary: Human seipin occupies the ER membrane and concentrates at ER–LD contacts.

Reason: The inspected human A431 experiments show reticular WT seipin-GFP and puncta next to forming lipid droplets. Endogenous chromosomal tagging and immuno-EM corroborate contact-site localization, with the authors noting membrane preservation limits in EM. WT rescue and comparison with A212P support the functional relevance of this ER compartment; the result is not limited to the overexpressed disease mutant.

Summary: Seipin is an ER membrane component of the promethin-associated assembly machinery.

Reason: The inspected localization experiments place tagged human seipin in the ER in MCF7 cells and examine its association with promethin. Promethin changes its ER/LD distribution, whereas those dynamics do not imply that seipin leaves the ER membrane for the mature droplet monolayer. The broad ER membrane assertion is supported, independently corroborated by endogenous tagging in PMID:31708432.

Summary: Seipin remains at ER–LD contacts during droplet maturation.

Reason: In human SUM159 cells, endogenously tagged seipin and LDAF1 mark nascent droplet sites. As droplets grow, LDAF1 redistributes to their surface while seipin remains at the ER contact. This supports ER membrane localization and distinguishes seipin from its mobile partner; it does not identify mature-droplet monolayer residence as seipin’s principal location.

Summary: The electronic ER membrane assignment agrees with direct localization.

Reason: The ARBA/subcellular-location mapping is independently supported by PMID:14981520, PMID:27879284 and PMID:31708432. Those experiments establish the location without requiring a new audit of every ARBA rule predicate.

Summary: The ER–lipid droplet contact site is a more precise localization.

Reason: PMID:27879284 directly localizes human seipin to ER–LD contacts by live-cell imaging, endogenous tagging and EM, and links those contacts to cargo delivery. GO:0005811 is not false merely because seipin remains ER-embedded: its definition allows associated proteins. However, the verified GO:0160259 definition names exactly the contact between ER membrane and lipid droplet, without implying monolayer residence. Propose that specific contact-site term for this well-resolved IDA assertion.

Proposed replacements: endoplasmic reticulum membrane-lipid droplet contact site

Summary: The source-specific seipin lipid-droplet localization assay remains uninspected.

Reason: The PMID:30970241 abstract describes DFCP1-positive nascent structures and a BSCL2 requirement for their fusion and expansion. It does not expose the seipin localization experiment underlying this IDA row. Other papers establish seipin at ER–LD contacts, but do not determine the imaging resolution or localization asserted in this particular source. Preserve the experimental row as unresolved, rather than reject it because the title foregrounds DFCP1.

Summary: The broad lipid-droplet association mapping is compatible with ER–LD contacts.

Reason: The UniProt SL-0154 mapping records broad lipid-droplet association, which is compatible with seipin remaining embedded in the ER at the contact. GO:0005811 includes associated proteins. Direct human contact-site evidence in PMID:27879284 and PMID:31708432 supports this broad association. Retain the electronic mapping at its source granularity; the imaging-resolved PMID:27879284 IDA row is separately refined to GO:0160259. The two judgments distinguish annotation resolution rather than contradictory compartments.

Summary: Conserved lipid storage follows from seipin-dependent lipid-droplet assembly.

Reason: The source IBA at PTN000476621 is consistent with seipin’s physical contribution to droplet assembly and growth. The same node/term is exposed in the official FlyBase record; the full IBD and tree were not recovered. Human patient-cell lipid-storage abnormalities and human assembly experiments support the target biology. Donor count and inclusion of human BSCL2 itself are not reasons to reject the propagation.

Summary: The seipin-family lipid-storage mapping is biologically appropriate.

Reason: The IPR009617 mapping agrees with direct human seipin evidence for organized lipid-droplet assembly and neutral-lipid accumulation. This broad lipid-storage process is supported by the target biology, independently of the family name.

Summary: Seipin deficiency disrupts cellular neutral-lipid storage.

Reason: The complete abstract reports lymphoblastoid cell lines from 12 patients with seipin null mutations, distinguished from eight AGPAT2-deficient lines and nine controls. Seipin deficiency changes triglyceride content and droplet size/number. The original full experiment was unavailable, but the described human phenotype and independent human assembly/rescue work support lipid storage. AGPAT2 catalysis and the downstream Delta9-desaturation defect are not attributed as seipin catalytic activities.

Summary: Lipid-droplet organization is a conserved seipin function.

Reason: PTN000476621 is the actual source node and is also displayed for this process on the official FlyBase seipin record. The complete ancestral reconstruction was unavailable; direct human patient-cell, knockout/rescue and assembly-site studies independently support organization of droplet size, formation and growth. No target-specific divergence contradicts the IBA.

Summary: Human seipin deficiency alters droplet number and size.

Reason: The complete PMID:19278620 abstract explicitly reports more numerous, smaller droplets in seipin-deficient patient cell lines, separate from the AGPAT2 comparison. This supports organization at the phenotype level. More recent human contact-site and rescue experiments clarify a physical assembly role; the original abstract is not used to invent fine assay details.

Summary: The adipocyte-differentiation transfer is defensible but cell-context dependent.

Reason: The source Q9Z2E9 is mouse Bscl2. The official MGI record carries experimental fat-cell differentiation annotations, including J:183701, resolved to PMID:22269949; its normally cached abstract describes impaired terminal white-adipocyte differentiation after Bscl2 loss. The exact historical GO_REF donor choice and a second MGI reference J:198139 were not resolved. In contrast, cached PMID:27748422 reports largely normal differentiation of its Bscl2-deficient brown preadipocyte model. Retain the broad transferred process as non-core with this white/brown and differentiation-stage boundary. This judgment is limited to the observed differentiation context.

Summary: Seipin can restrain lipolysis in an adipocyte context.

Reason: MGI links the mouse donor’s experimental negative regulation of lipid catabolism to J:183701, verified as PMID:22269949. The normally cached primary abstract reports excess cAMP/PKA-associated lipolysis after Bscl2 loss in differentiating mouse cells, with differentiation rescue by lipolysis inhibitors. The normal cache contains the complete abstract; full original Methods/Results remain inaccessible. This supports a contextual regulatory transfer, not lipase catalysis or an invariant effect in every tissue: cached PMID:27748422 finds little cell-autonomous lipolysis change in its brown-adipocyte model.

Summary: Reduced cold-adaptive thermogenesis is a downstream phenotype of generalized seipin-deficient lipodystrophy in this mouse study.

Reason: PMID:27748422 reports reduced maximal norepinephrine-stimulated thermogenic capacity and persistent shivering in cold-acclimated global Bscl2-knockout mice. In the tested brown-adipocyte cultures, some thermogenic transcripts and UCP1 protein were reduced, but basal and beta3-stimulated respiration, lipolysis and insulin signaling were largely preserved. The authors interpret the organismal defect through white-fat failure, substrate/adipokine supply and secondary insulin resistance. Non-cell-autonomous regulation can satisfy GO:0120162; that feature alone is not a reason to reject the term. Here, however, the experiments do not distinguish a specific seipin-mediated thermogenic regulatory step from the systemic consequences of lipodystrophy. Mark the mouse-to-human assignment as over-annotated while retaining the real physiological phenotype and its limits.

Summary: Seipin organizes sites and contacts that support lipid-droplet formation.

Reason: The cached PMID:31178403 abstract reports seipin relocalization, uniform ER–LD necks and acute-removal effects. The institutional author manuscript was additionally inspected for relevant human A431 endogenous tagging, nuclear-envelope trapping and degron experiments. Together with human assembly-site experiments in PMID:31708432, these support a physical organizing role in formation. The canonical cache remains abstract-only; no additional quotations or equivalence across all isoforms are asserted.

Summary: Seipin and LDAF1 define lipid-droplet assembly sites.

Reason: Endogenous tagging, live imaging and relocalization experiments in human SUM159 cells show droplets emerging at LDAF1–seipin sites and following ectopically recruited assembly machinery. The purified-complex experiments use recombinant seipin residues 1–310 and LDAF1 in mammalian cells, so they are not claimed to assay every full-length isoform. Seipin supplies part of the organizing structure; this is process participation rather than a necessity-only inference. The proposed triglyceride phase-transition mechanism does not imply chemical triglyceride synthesis by seipin.

Summary: Seipin is required for productive maturation of nascent droplets.

Reason: Most detailed dynamics in PMID:27564575 use Drosophila S2 cells, but the inspected study also tests seipin-deficient human SUM159 cells and patient fibroblasts and reports the abnormal early-droplet phenotype. Human seipin rescues the fly depletion phenotype. Together these support the conserved formation/maturation role while keeping the fly-specific domain and imaging experiments distinct from direct human assays.

Summary: Human seipin supports functional ER–LD contacts and droplet growth.

Reason: Human A431 knockout, WT rescue, endogenous tagging, patient fibroblasts and cargo-flux experiments in PMID:27879284 link seipin to productive droplet biogenesis. Initial neutral-lipid synthesis and initial cargo recruitment are not abolished; later ER–LD exchange and growth are defective. This identifies a structural organization and delivery role within droplet formation, without attributing lipid-synthetic chemistry to seipin.

Summary: Seipin provides a membrane-contact tether that supports exchange between the ER and growing lipid droplets.

Reason: GO:0170007 describes membrane-lipid binding that brings ER and lipid droplets together for contact and exchange. In human A431 cells, PMID:27879284 combines endogenous localization, knockout, wild-type rescue, ultrastructure and cargo-flux assays; a subset of droplets detaches and remaining contacts become abnormal after seipin loss. Patient fibroblasts corroborate altered droplet dynamics. PMID:31178403 supplies complementary contact-relocation and acute-depletion evidence, while PMID:30293840 directly reports human seipin lipid binding. Together these identify a structural contact activity rather than inferring it from localization or knockout necessity alone. The term is an adaptor MF, not an ancestor or descendant of the retained phospholipid-binding MF or a new biological-process assertion. No purified minimal human tether reconstitution is claimed.