ELOVL4

Summary: Retain inherited ER membrane activity with target-specific experimental corroboration.

Reason: The literal positive IBD at PTN000125390 is on the path to human Q9GZR5 leaf PTN002476773 in PTHR11157, and the ungapped target MSA sequence exactly matches the official 314-residue product. The complete saved IBD scan finds no recorded loss or negation on that path. The target itself is a legitimate experimental contributor to the ancestral inference, not circular evidence. Human ELOVL4 localization and membrane assays independently support the site of activity. The current IBD and GOA donor lists differ in some identifiers; both literal versions are retained without inventing a historical remapping.

Summary: Retain phylogenetically supported fatty-acid elongase activity.

Reason: The literal positive IBD at PTN000125390 is on the path to human Q9GZR5 leaf PTN002476773 in PTHR11157, and the ungapped target MSA sequence exactly matches the official 314-residue product. The complete saved IBD scan finds no recorded loss or negation on that path. Current target EXP records and the human ELOVL4 membrane assay corroborate the condensing function. GO:0009922 names the first condensation step of the elongation cycle; it does not assert that ELOVL4 performs the subsequent reduction, dehydration and final reduction reactions. Differences between current IBD and GOA donor identifiers do not remove the authenticated placement.

Summary: Retain very long-chain fatty-acid biosynthesis.

Reason: The literal positive IBD at PTN000125390 is on the path to human Q9GZR5 leaf PTN002476773 in PTHR11157, and the ungapped target MSA sequence exactly matches the official 314-residue product. The complete saved IBD scan finds no recorded loss or negation on that path. The human membrane experiment uses C24:0-CoA and C26:0-CoA and supports further elongation in the greater-than-22-carbon range of the official definition. This is not a claim that ELOVL4 is the only enzyme producing very long-chain lipids, nor a transfer of every donor substrate range. Target self-evidence is legitimate.

Summary: Retain the inherited contribution to sphingolipid biosynthesis as lipid-pathway context.

Reason: The literal positive IBD at PTN000125390 is on the path to human Q9GZR5 leaf PTN002476773 in PTHR11157, and the ungapped target MSA sequence exactly matches the official 314-residue product. The complete saved IBD scan finds no recorded loss or negation on that path. The IBD is experimentally grounded in descendants including human ELOVL1, whose current IMP annotation cites the separately inspected sphingolipid experiments in PMID:20937905. ELOVL4 supplies elongated acyl chains used by downstream lipid synthesis; it is not assigned the ceramide-synthase reaction. The ELOVL4–CERS2 association is compatible with shared machinery but does not establish that specific catalytic step or a native fixed complex. Retain the sound ancestral pathway placement at non-core strength.

Summary: Retain polyunsaturated fatty-acid elongation.

Reason: The literal positive IBD at PTN000125390 is on the path to human Q9GZR5 leaf PTN002476773 in PTHR11157, and the ungapped target MSA sequence exactly matches the official 314-residue product. The complete saved IBD scan finds no recorded loss or negation on that path. The conserved enzymatic role is independently supported by mouse Elovl4 conditional ablation, which markedly lowers retinal C30–C34 VLC-PUFA products. That study compares endogenous mouse conditional loss with a separate human STGD3 transgene model; it is not a purified human enzyme assay. The human saturated-substrate panel does not assay the full polyunsaturated repertoire and is not used to negate this placement.

Summary: Retain saturated fatty-acid elongation.

Reason: The literal positive IBD at PTN000125390 is on the path to human Q9GZR5 leaf PTN002476773 in PTHR11157, and the ungapped target MSA sequence exactly matches the official 314-residue product. The complete saved IBD scan finds no recorded loss or negation on that path. The human ELOVL4 membrane assay reports weak but significant C24:0-CoA and C26:0-CoA elongation-associated output. This directly corroborates the saturated-chain process while leaving precise product-length distribution and number of cycles unresolved. The target is legitimately among the IBD evidence contributors.

Summary: Retain the inherited monounsaturated elongation context without claiming an unmeasured human substrate spectrum.

Reason: The literal positive IBD at PTN000125390 is on the path to human Q9GZR5 leaf PTN002476773 in PTHR11157, and the ungapped target MSA sequence exactly matches the official 314-residue product. The complete saved IBD scan finds no recorded loss or negation on that path. A current human ELOVL1 donor IDA record for this exact term is linked to PMID:20166112, grounding the ancestral placement beyond a family name. The inspected ELOVL4 panel in PMID:20937905 includes C18:1(n-9)-CoA as its only monounsaturated substrate; its reported positive ELOVL4 outputs are C24:0/C26:0. That limited panel cannot establish general loss of monounsaturated elongation. Retain the valid phylogenetic assertion at non-core strength, with the human ELOVL4 monounsaturated range unresolved rather than asserted as directly measured.

Summary: Refine broad ER localization to the established ER membrane compartment.

Reason: The target has the exact ELOVL4 InterPro family assignment IPR033678, whose current mapping emits the broad ER term. Independent human localization and membrane activity resolve the compartment to GO:0005789. ER membrane is part_of ER and is_a membrane in the captured ontology; this is a compartment refinement using the whole target evidence, not a claim that the InterPro mapping itself specifies membrane topology.

Proposed replacements: endoplasmic reticulum membrane

Summary: Retain ER membrane localization while exposing rule-version limits.

Reason: The current UR000254926 condition set is satisfied by the target HAMAP MF_03204 assignment, vertebrate lineage and non-fragment status. The explicit SL-0097 mapping and human localization independently corroborate the term. The additional current ARBA00028685 support has no fully reconstructed target-matching condition set: 39 sets require FunFam membership not established in the captured target record. This is a rule-applicability gap, not evidence against the localization, and the exact imported source and current support lists remain unchanged.

Summary: Represent the unsaturated biosynthetic contribution as unsaturated fatty-acid elongation.

Reason: The current UR000254926 condition set is satisfied by the target HAMAP MF_03204 assignment, vertebrate lineage and non-fragment status. ELOVL4 elongates pre-existing unsaturated acyl chains rather than introducing double bonds. The accepted polyunsaturated role and valid monounsaturated phylogenetic placement support GO:0019368, which states that operative elongation process. This is an explicitly lateral mechanistic replacement: the captured ontology does not place this elongation branch under GO:0006636. It does not deny the broader unsaturated biosynthetic contribution or assert a desaturase activity.

Proposed replacements: fatty acid elongation, unsaturated fatty acid

Summary: Remove the visible-light detection inference generated from the unsupported GO:0008020 premise.

Reason: The captured WITH/FROM is GO:0008020. GO:0009584 concerns stimulus reception and conversion to a molecular signal; fatty-acid synthesis needed for retinal function does not establish this step. Reassess the upstream molecular-function assertion rather than inferring absence of any role in vision.

Summary: Retain fatty-acid elongase activity with multiple independent supporting mappings.

Reason: The current UR000254926 condition set is satisfied by the target HAMAP MF_03204 assignment, vertebrate lineage and non-fragment status. The ELO family and ELOVL4-specific InterPro memberships, EC/Rhea reaction mapping, mouse donor and direct human membrane assay converge on the condensation activity. ARBA00044377 returned HTTP 404 in the bounded official retrieval, so its present condition set is not claimed verified. That unavailable support does not overturn the independently established function. No downstream elongation-cycle enzyme activities are attributed to ELOVL4.

Summary: Refine the correct but general membrane assertion to ER membrane.

Reason: The IPR002076 ELO-family and matching UniRule support the membrane association. The exact human target is independently localized to the ER and assayed in membranes; GO:0005789 is a verified membrane descendant. The former over-annotation disposition treated lack of specificity as a biological defect. A supported compartment refinement is appropriate instead.

Proposed replacements: endoplasmic reticulum membrane

Summary: Retain saturated fatty-acid elongation.

Reason: The current UR000254926 condition set is satisfied by the target HAMAP MF_03204 assignment, vertebrate lineage and non-fragment status. The ELOVL4-specific InterPro mapping emits this term, and the human membrane assay directly supports elongation-associated output from saturated C24:0-CoA/C26:0-CoA. The shared electronic support is distinguished from the actual experimental corroboration; neither supplies a complete resolved product-length distribution.

Summary: Retain fatty-acid elongation as the common process across supported substrate classes.

Reason: The current ARBA00028259 condition set 0 is literally satisfied by IPR002076 and Primates in the official target record. Its GO:0030497 output matches sequential two-carbon extension. Saturated and polyunsaturated elongation are distinct descendants, while very long-chain biosynthesis constrains chain length on a separate ontology branch. The inclusive elongation process correctly unifies the established substrate classes and is not replaced by a single subtype that would exclude the others.

Summary: Retain polyunsaturated fatty-acid elongation.

Reason: The current UR000254926 condition set is satisfied by the target HAMAP MF_03204 assignment, vertebrate lineage and non-fragment status. The named mouse ELOVL4 donor is experimentally annotated from PMID:23479632. Its conditional loss strongly reduces retinal VLC-PUFA content, supporting the conserved biosynthetic step. The paper does not directly assay an isolated human product or identify all human disease variants with the same mechanism. The direct human saturated assay complements rather than replaces this donor evidence.

Summary: Replace the mismatched long-chain product range with established very long-chain biosynthesis.

Reason: The current UR000254926 condition set is satisfied by the target HAMAP MF_03204 assignment, vertebrate lineage and non-fragment status. GO:0035338 explicitly specifies 13–22-carbon fatty-acyl groups; it is not a general parent for all chain lengths. The directly positive human ELOVL4 substrates are C24:0-CoA and C26:0-CoA, already beyond that range, and the mouse evidence establishes still longer retinal products. GO:0042761 captures the established greater-than-22-carbon biosynthetic role. This is a lateral correction of the product-range framing, not an asserted absence of every possible shorter-substrate reaction and not a claim that fatty-acyl-CoA and free-fatty-acid ontology branches are identical.

Proposed replacements: very long-chain fatty acid biosynthetic process

Summary: Retain very long-chain fatty-acid biosynthesis.

Reason: The current UR000254926 condition set is satisfied by the target HAMAP MF_03204 assignment, vertebrate lineage and non-fragment status. The specific InterPro mapping and direct human C24:0/C26:0 membrane assay support this term. Mouse donor and retinal conditional-loss evidence independently support very long polyunsaturated products. The evidence is not used to assign identical substrate spectra to every ELO family member.

Summary: Retain all verified HuRI interaction pairs as generic non-core binding.

Reason: All 92 inherited UniProt partner identifiers have exact positive ELOVL4 pair records in the saved IntAct export for PMID:32296183. Each pair has the curated pooling, array and validated-two-hybrid records; these are not counted as three independent physiological validations. The original Results describe quadruplicate pairwise retesting and sequence confirmation, with orthogonal assays used for dataset-level benchmarking. The literal records identify human proteins tested in yeast and preserve fusion features and reference sequence digests. They do not establish a native ER complex, present-day insert equivalence, or pair-specific MAPPIT/GPCA confirmation. Generic binding is retained under campaign policy; membrane localization alone is not a false-hit argument, and partner class alone does not warrant a functional subtype.

Summary: Preserve the positive ELOVL4–TECR assertion while the source-specific assay remains unverified.

Reason: The imported IPI record names TECR and is biologically credible in elongation machinery. The authentic abstract establishes human HACD2–TECR biochemical analysis and discusses competition involving ELOVL proteins, but does not resolve the ELOVL4 pair or its preparation. Bounded publisher, article-API and indexed routes did not recover the operative ELOVL4 Methods/Results. The current IntAct export has no record for this PMID; that absence is not negative evidence. Retain uncertainty about this specific evidence rather than calling the interaction false, transferring HACD2 assay details, or retaining an over-annotation merely because the term is generic.

Summary: Rhythmic rat Elovl4 transcript expression is verified, but protein participation in the timed process remains unresolved.

Reason: The current rat donor annotation cites PMID:24736612 with IEP evidence. Under a 12-hour light/12-hour dark schedule, control rat retina showed rhythmic Elovl4 mRNA by time-series qRT-PCR, whereas diabetic retina lost that pattern. The complete original Methods, Results and Discussion were accessible and read. GO:0007623 encompasses an approximately 24-hour recurring biological process; it does not require a clock-regulator role. The observed expression rhythm is positive evidence compatible with rhythmic lipid metabolism, but it does not distinguish timed ELOVL4 protein activity from regulation of Elovl4 transcript production. Whether the normal protein participates in the recurring process, and whether that role supports the human orthology transfer, therefore remains scientifically unresolved. UNDECIDED records this functional uncertainty rather than an access failure, a finding of over-annotation, or a claim that ELOVL4 lacks a circadian role.

Summary: The exact negative sign of the transferred miniature excitatory response is unresolved.

Reason: The current rat donor records cite PMID:32780351 and PMID:37491316. The former measures retinal electroretinograms and lipid/anatomical phenotypes, not miniature excitatory postsynaptic currents. In the latter, homozygous W246G rats have reduced Purkinje-cell mEPSC frequency with unchanged amplitude relative to wild type. This is a positive synaptic phenotype, but it does not directly establish that the normal human protein negatively regulates the miniature excitatory response. W246G is a selective lipid-pathway perturbation rather than an authenticated clean loss of all normal ELOVL4 function, and effects differ between synapse types. Keep uncertainty about the signed transfer rather than reversing its sign or dismissing the rat evidence.

Summary: The exact positive sign of the transferred inhibitory response is unresolved.

Reason: The current rat donor records cite PMID:32780351 and PMID:37491316. The retinal ERG study does not isolate inhibitory synaptic currents. The later cerebellar study directly finds increased mIPSC frequency and amplitude in Purkinje cells of homozygous W246G rats relative to wild type. This establishes a mutation-associated inhibitory phenotype, but does not by itself establish positive regulation by normal human ELOVL4. The mutation is not assumed to be a clean loss of normal function, and the same study documents input-specific effects. Retain the positive observations while leaving the precise normal-product regulatory sign unresolved.

Summary: Retain the measured rat short-term facilitation phenotype as a contextual, non-core regulatory role.

Reason: PMID:37491316 measures reduced paired-pulse facilitation at parallel-fiber–Purkinje-cell synapses of homozygous W246G rats at 20, 50 and 100 ms intervals (Figure 3A), with reduced initial facilitation during stimulus trains (Figure 3B,D). These are direct measurements of the short-term potentiation phenotype described by GO:1990926. The term is a subtype of regulation of synaptic plasticity (GO:0048167), under modulation of chemical synaptic transmission (GO:0050804); it does not require the annotated protein itself to release neurotransmitter. The existing rat experimental evidence therefore supports the human orthology-derived annotation as a non-core contextual role. ELOVL4-dependent lipid production provides a biologically grounded regulatory explanation, but its specific mediation of this phenotype remains inferred: the Discussion proposes, rather than reports, lipid rescue in these W246G rats. Climbing-fiber effects differ, W246G is a selective missense allele rather than a complete null, and this is not direct human experimentation. These limits constrain the mechanism and scope without negating the measured facilitation phenotype.

Summary: Refine broad fatty-acid biosynthesis to established very long-chain biosynthesis.

Reason: The inherited UniPathway UPA00094 assertion is a broad pathway mapping. ELOVL4 directly supplies the condensation step of very long-chain production, supported by the human C24:0/C26:0 membrane experiment and mouse retinal VLC-PUFA depletion. GO:0042761 is a verified is_a descendant of fatty-acid biosynthesis. This refinement uses independent target evidence; the bounded historical UniPathway endpoint recovery did not establish a live original pathway record.

Proposed replacements: very long-chain fatty acid biosynthetic process

Summary: Human ELOVL4 is localized to the endoplasmic reticulum membrane.

Reason: The original Results report ER localization of all seven expressed ELOVL proteins, including human ELOVL4; the same study assays ELOVL4 in HEK293T membrane fractions and reports Endo-H-sensitive glycosylation. This supports the established ER membrane location. The recovered main text does not provide the individual supplemental S2 pixels or detailed fixation/marker conditions, and fractionation alone does not determine membrane topology.

Summary: ELOVL4 enables the condensing step of fatty-acid elongation.

Reason: Human N-terminally 3xFLAG-tagged ELOVL4 in HEK293T total membranes produces weak but significant labeled fatty-acid output with C24:0-CoA and C26:0-CoA relative to vector controls (Figure 1B). GO:0009922 describes the initial acyl-CoA/malonyl-CoA condensation step, not all four reactions of the elongation cycle. The membrane assay supports this established enzyme function without demonstrating a purified ELOVL4-only intermediate reaction, kinetic constants or a resolved ELOVL4 product-length distribution.

Summary: Retain elongase activity transferred from the mouse ortholog and corroborated in the human target.

Reason: The literal donor Q9EQC4 is mouse Elovl4, with multiple current experimental annotations to GO:0009922, including the conditional-loss study PMID:23479632. Human ELOVL4 membrane experiments in PMID:20937905 independently establish the corresponding elongation-associated chemistry. The inference is not based solely on an enzyme-family name, and no precise mouse-only product spectrum is automatically transferred to human.

Summary: Retain polyunsaturated elongation supported by the mouse ortholog.

Reason: The exact current donor Q9EQC4 carries an IMP annotation to this term from PMID:23479632. In the genuine original, conditional mouse Elovl4 ablation strongly reduces retinal C30–C34 VLC-PUFA products. This supplies a biological role for the conserved enzyme, while distinguishing mouse conditional loss from the separate human STGD3 transgene model and from an isolated human enzyme assay.

Summary: Retain the experimentally reported ELOVL4–CERS2 association.

Reason: The original main Results explicitly report co-immunoprecipitation of HA-tagged CERS2 with every FLAG-tagged ELOVL, including ELOVL4, in the S8B experiment. The imported partner Q96G23 is human CERS2. This supports the generic binding assertion at cellular association strength under the project policy. The authors allow indirect association through common elongation machinery; the unavailable S8 Methods/pixels leave exact conditions unresolved. Neither a purified binary interaction nor a specific adapter or enzyme-regulatory function follows from the partner class.

Summary: Refine the ER localization to the established ER membrane compartment.

Reason: The original Results report ER localization of expressed human ELOVL4. Independent target-specific membrane-fraction/activity evidence, the established membrane protein architecture, and the separately supported GO:0005789 annotation resolve the functional location to the ER membrane. This is a supported compartment refinement of the broader ER assertion, not a claim that the inaccessible S2 panel independently resolved membrane topology.

Proposed replacements: endoplasmic reticulum membrane

Summary: Retain ER membrane localization of wild-type human ELOVL4.

Reason: The recovered original reports sequence-verified human retinal ELOVL4 cDNA, with N-terminal tags, and wild-type localization overlapping calnexin in COS-7 cells (Figure 4). Untagged wild-type protein reportedly has the same distribution, with those data not shown. The localization and established membrane protein identity support the ER membrane annotation; the co-immunoprecipitation and heterogeneous detergent complexes do not establish a defined oligomeric stoichiometry or catalytic activity. The experimental insert has not been independently aligned to the current 314-residue reference.

Summary: Retain saturated fatty-acid elongation as a direct ELOVL4 function.

Reason: The human ELOVL4 membrane assay reports significant elongation-associated output with the saturated acyl-CoA substrates C24:0-CoA and C26:0-CoA compared with vector (Figure 1B). This is direct evidence for participation in saturated-chain elongation. The normal-phase TLC readout does not resolve the number of cycles or a precise ELOVL4 product-length distribution, and these panels are not skin-barrier or retinal experiments.

Summary: Retain very long-chain biosynthesis while identifying the actual paralog donor.

Reason: The literal donor Q9BW60 is human ELOVL1, not the mouse ELOVL4 ortholog. Current ELOVL1 IDA annotations include PMID:20937905 and PMID:20166112. The independently inspected PMID:20937905 also assays human ELOVL4 directly with C24:0/C26:0 substrates, corroborating this shared biosynthetic function on the target. This supports the term without importing ELOVL1-specific signaling effects or assuming identical substrate preferences.

Summary: Retain very long-chain fatty-acid biosynthesis.

Reason: Human ELOVL4 expression in HEK293T membrane preparations increases elongation-associated fatty-acid output from C24:0-CoA and C26:0-CoA. Both substrates already fall within the current GO definition of very long-chain fatty acids, and ELOVL4 supplies the condensing activity for further biosynthesis. The study does not directly resolve ELOVL4-specific product chain lengths or establish its full polyunsaturated substrate range; ELOVL1-specific knockdown and signaling experiments are not transferred to ELOVL4.

Summary: Refine the broad biosynthetic annotation to very long-chain fatty acid biosynthesis.

Reason: The original homology-based claim is consistent with ELOVL4’s established elongation role. Use the more specific GO:0042761, a descendant of GO:0006633, for this same biosynthetic function. Independent human ELOVL4 membrane assays in PMID:20937905 support elongation of very-long-chain acyl-CoA substrates; this does not make the 2001 study a direct biochemical assay.

Proposed replacements: very long-chain fatty acid biosynthetic process

Summary: Remove unsupported G protein-coupled photoreceptor activity.

Reason: GO:0008020 requires light reception and activation of a heterotrimeric G protein. The recovered PMID:11138005 Methods and Results establish linkage, cloning, expression and sequence homology; they do not assay that activity. Its Discussion proposes an ER fatty-acid elongation role. Independent human ELOVL4 membrane assays in PMID:20937905 support elongation. Photoreceptor-cell expression does not itself establish photoreceptor molecular function.