ACSL4 (FACL4) is a membrane-associated, ATP-dependent long-chain fatty acid-CoA ligase that activates fatty acids for cellular lipid metabolism. Recombinant human variants preferentially activate highly unsaturated substrates including arachidonate, eicosapentaenoate, docosahexaenoate and adrenate. The resulting acyl-CoAs supply membrane-lipid synthesis and remodeling, helping determine the abundance of peroxidation-susceptible phospholipids and cellular sensitivity to ferroptosis. ACSL4 has experimentally supported pools at the endoplasmic reticulum and mitochondrial outer membrane, with plasma-membrane, ER-mitochondria contact-site and lipid-droplet distributions that vary with variant and cellular context. Loss-of-function variants cause X-linked intellectual disability, linking fatty-acid activation to nervous-system development and function.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0001676 long-chain fatty acid metabolic process | IBA GO_REF:0000033 | ACCEPT | Summary: ACSL4 activates long-chain fatty acids for cellular lipid metabolism. Reason: The PAINT inference agrees with recombinant human ACSL4 activity and human-cell lipid metabolism. No target-specific loss of the inherited activity is evident. Propagation Review Root cause: NO FAILURE CORE Sources checked: PANTHER:PTN000645126 SUPPORTS TRANSFER Proximate PAINT ancestral node from the seeded provenance. The inherited assertion is consistent with the target evidence discussed above; the full ancestral-node placement was not independently reconstructed. Target self-evidence among descendants would not be circular. Supporting Evidence: PMID:9598324 The cDNA encodes a functional long-chain fatty acid-CoA ligase that shows preference for arachidonic acid as substrate PMID:31061331 both ACSL4 variants preferred various kinds of highly unsaturated fatty acids (HUFAs), including docosahexaenoic acid (DHA), adrenic acid (docosatetraenoic acid) and eicosapentaenoic acid (EPA), as well as AA as a substrate |
| GO:0005783 endoplasmic reticulum | IBA GO_REF:0000033 | ACCEPT | Summary: ACSL4 has an experimentally supported endoplasmic reticulum pool. Reason: Endogenous ACSL4 follows calnexin in human HT1080 and MCF-7 fractionation and confocal imaging (PMID:29450800). Human variant localization in PMID:24269233 also supports ER association. Retain the PAINT organelle-level annotation without inferring a particular membrane topology. Propagation Review Root cause: NO FAILURE CORE Sources checked: PANTHER:PTN000644924 SUPPORTS TRANSFER Proximate PAINT ancestral node from the seeded provenance. The inherited assertion is consistent with the target evidence discussed above; the full ancestral-node placement was not independently reconstructed. Target self-evidence among descendants would not be circular. Supporting Evidence: PMID:29450800 the ACSL4 localisation pattern more closely followed that of calnexin which is an endoplasmic reticulum resident chaperone |
| GO:0030182 neuron differentiation | IBA GO_REF:0000033 | KEEP AS NON CORE | Summary: ACSL4 supports neuronal development in a conserved developmental context. Reason: In PMID:19617635, human wild-type ACSL4 rescues neuronal/glial and visual-wiring defects of Drosophila dAcsl mutants, whereas patient variants do not. This positive functional evidence supports the PAINT inference; the developmental output is contextual relative to fatty-acid activation. It is not inferred solely from intellectual disability. Propagation Review Root cause: NO FAILURE NON CORE Sources checked: PANTHER:PTN001186315 SUPPORTS TRANSFER Proximate PAINT ancestral node from the seeded provenance. The inherited assertion is consistent with the target evidence discussed above; the full ancestral-node placement was not independently reconstructed. Target self-evidence among descendants would not be circular. Supporting Evidence: PMID:19617635 All these defects in Drosophila brain were rescued by the wild-type ACSL4 but not by the mutant products found in MRX patients |
| GO:0005886 plasma membrane | IBA GO_REF:0000033 | ACCEPT | Summary: Human ACSL4 variant 1 can associate with the plasma membrane. Reason: The full primary author manuscript for PMID:24269233 reports FLAG-tagged human variant 1 mainly at the plasma membrane and partly at ER in HeLa cells (Results 3.2); variant 2 was predominantly ER. This supports a genuine plasma-membrane pool without claiming that all variants or cell types share the distribution. Propagation Review Root cause: NO FAILURE CORE Sources checked: PANTHER:PTN000645126 SUPPORTS TRANSFER Proximate PAINT ancestral node from the seeded provenance. The inherited assertion is consistent with the target evidence discussed above; the full ancestral-node placement was not independently reconstructed. Target self-evidence among descendants would not be circular. |
| GO:0005811 lipid droplet | IBA GO_REF:0000033 | ACCEPT | Summary: ACSL4 is associated with lipid droplets in a cellular lipid-storage context. Reason: Retain the PAINT localization, consistent with the curated HuH7 droplet annotation from PMID:14741744. The original abstract emphasizes abundant ACSL3; that does not exclude lower-abundance ACSL4. A later primary paper by the same investigators explicitly compares ACSL3 with ACSL4 in lipid droplets (source route in notes). Propagation Review Root cause: NO FAILURE CORE Sources checked: PANTHER:PTN000645126 SUPPORTS TRANSFER Proximate PAINT ancestral node from the seeded provenance. The inherited assertion is consistent with the target evidence discussed above; the full ancestral-node placement was not independently reconstructed. Target self-evidence among descendants would not be circular. |
| GO:0035336 long-chain fatty-acyl-CoA metabolic process | IBA GO_REF:0000033 | ACCEPT | Summary: ACSL4 directly produces long-chain fatty acyl-CoAs. Reason: ATP-dependent fatty-acid activation forms the CoA thioester, a direct step of long-chain fatty-acyl-CoA metabolism. Human substrate assays support the PAINT inference. Propagation Review Root cause: NO FAILURE CORE Sources checked: PANTHER:PTN000645126 SUPPORTS TRANSFER Proximate PAINT ancestral node from the seeded provenance. The inherited assertion is consistent with the target evidence discussed above; the full ancestral-node placement was not independently reconstructed. Target self-evidence among descendants would not be circular. Supporting Evidence: PMID:9598324 The cDNA encodes a functional long-chain fatty acid-CoA ligase that shows preference for arachidonic acid as substrate PMID:31061331 both ACSL4 variants preferred various kinds of highly unsaturated fatty acids (HUFAs), including docosahexaenoic acid (DHA), adrenic acid (docosatetraenoic acid) and eicosapentaenoic acid (EPA), as well as AA as a substrate |
| GO:0047676 arachidonate-CoA ligase activity | IBA GO_REF:0000033 | ACCEPT | Summary: Arachidonate activation is a well-established ACSL4 activity. Reason: The original human cDNA study and recombinant human variant assays directly establish arachidonate-CoA ligase activity, consistent with the inherited PAINT assertion. Propagation Review Root cause: NO FAILURE CORE Sources checked: PANTHER:PTN002878360 SUPPORTS TRANSFER Proximate PAINT ancestral node from the seeded provenance. The inherited assertion is consistent with the target evidence discussed above; the full ancestral-node placement was not independently reconstructed. Target self-evidence among descendants would not be circular. Supporting Evidence: PMID:9598324 The cDNA encodes a functional long-chain fatty acid-CoA ligase that shows preference for arachidonic acid as substrate PMID:31061331 both ACSL4 variants preferred various kinds of highly unsaturated fatty acids (HUFAs), including docosahexaenoic acid (DHA), adrenic acid (docosatetraenoic acid) and eicosapentaenoic acid (EPA), as well as AA as a substrate |
| GO:0000166 nucleotide binding | IEA GO_REF:0000043 | MODIFY | Summary: The generic nucleotide-binding mapping can be made specific to ATP. Reason: ACSL4 uses ATP in the acyl-CoA synthetase reaction. The keyword is biologically correct but less informative than the supported ATP-binding term; this is a specificity refinement, not excess biological activity. Propagation Review Root cause: TERM SCOPING PROBLEM Failure modes: GRANULARITY MISMATCH Sources checked: UniProtKB-KW:KW-0547 SUPPORTS TRANSFER Nucleotide-binding keyword is compatible with the ATP-dependent reaction; ATP binding supplies the supported specificity. Proposed replacements: ATP binding Supporting Evidence: PMID:38720107 240 ΞΌg of purified protein, 5 mM ATP, 100 mM Tris-HCl (pH 7.4), 250 ΞΌM coenzyme A, 10 ΞΌM AA-d8 |
| GO:0004467 long-chain fatty acid-CoA ligase activity | IEA GO_REF:0000120 | ACCEPT | Summary: The combined mappings correctly identify long-chain fatty acid-CoA ligase activity. Reason: The mouse Acsl4 ortholog, EC 6.2.1.3 and RHEA:15421 agree with direct assays of human ACSL4. The broad catalytic term includes the demonstrated C20 and C22 highly unsaturated substrates. Propagation Review Root cause: NO FAILURE CORE Sources checked: UniProtKB:Q9QUJ7 SUPPORTS TRANSFER Combined ortholog/reaction mapping agrees with directly characterized human ACSL4 activity. Q9QUJ7 and ENSMUSP00000033634 identify mouse Acsl4. ensembl:ENSMUSP00000033634 SUPPORTS TRANSFER Combined ortholog/reaction mapping agrees with directly characterized human ACSL4 activity. Q9QUJ7 and ENSMUSP00000033634 identify mouse Acsl4. RHEA:15421 SUPPORTS TRANSFER Combined ortholog/reaction mapping agrees with directly characterized human ACSL4 activity. Q9QUJ7 and ENSMUSP00000033634 identify mouse Acsl4. EC:6.2.1.3 SUPPORTS TRANSFER Combined ortholog/reaction mapping agrees with directly characterized human ACSL4 activity. Q9QUJ7 and ENSMUSP00000033634 identify mouse Acsl4. Supporting Evidence: PMID:31061331 both ACSL4 variants preferred various kinds of highly unsaturated fatty acids (HUFAs), including docosahexaenoic acid (DHA), adrenic acid (docosatetraenoic acid) and eicosapentaenoic acid (EPA), as well as AA as a substrate |
| GO:0005524 ATP binding | IEA GO_REF:0000043 | ACCEPT | Summary: ATP binding is integral to ACSL4 catalysis. Reason: The ATP-dependent acyl-CoA ligase reaction supports the UniProt ATP-binding keyword mapping. ATP is a reaction substrate, not a kinase-specific signal. Propagation Review Root cause: NO FAILURE CORE Sources checked: UniProtKB-KW:KW-0067 SUPPORTS TRANSFER ATP-binding keyword agrees with ATP as a substrate in the acyl-CoA synthetase reaction. Supporting Evidence: PMID:38720107 240 ΞΌg of purified protein, 5 mM ATP, 100 mM Tris-HCl (pH 7.4), 250 ΞΌM coenzyme A, 10 ΞΌM AA-d8 |
| GO:0005741 mitochondrial outer membrane | IEA GO_REF:0000044 | ACCEPT | Summary: ACSL4 has a mitochondrial outer-membrane pool. Reason: Retain the UniProt subcellular-location mapping. Independent human-cell mitochondrial subfractionation and immunoelectron microscopy in PMID:38720107 support an outer-membrane pool; the paper also reports intermembrane-space signal. The evidence does not justify assigning a universal integral-membrane topology. Propagation Review Root cause: NO FAILURE CORE Sources checked: UniProtKB-SubCell:SL-0172 SUPPORTS TRANSFER Outer-membrane vocabulary mapping is corroborated by human mitochondrial subfractionation; no universal topology is inferred. Supporting Evidence: PMID:38720107 ACSL4 was mainly located in outer membrane of mitochondria (OM) and IMS |
| GO:0005789 endoplasmic reticulum membrane | IEA GO_REF:0000044 | ACCEPT | Summary: ACSL4 associates with endoplasmic reticulum membranes. Reason: The location-vocabulary mapping agrees with endogenous human-cell fractionation/imaging and variant localization. Membrane association is supported; the nature of membrane insertion and relative abundance depend on construct and cell context. Propagation Review Root cause: NO FAILURE CORE Sources checked: UniProtKB-SubCell:SL-0097 SUPPORTS TRANSFER ER-membrane vocabulary mapping is supported by human fractionation/imaging and variant localization. Supporting Evidence: PMID:29450800 the ACSL4 localisation pattern more closely followed that of calnexin which is an endoplasmic reticulum resident chaperone |
| GO:0005886 plasma membrane | IEA GO_REF:0000044 | ACCEPT | Summary: A plasma-membrane pool of ACSL4 is supported by human variant imaging. Reason: Retain the location mapping using the variant 1 localization experiment in PMID:24269233 (full author manuscript, Results 3.2). Mitochondrial localization is not evidence for this compartment, and the repeated mapping does not create an independent experiment. Propagation Review Root cause: NO FAILURE CORE Sources checked: UniProtKB-SubCell:SL-0039 SUPPORTS TRANSFER Cell-membrane mapping is supported by the human variant 1 localization experiment, not by mitochondrial evidence. |
| GO:0006629 lipid metabolic process | IEA GO_REF:0000043 | MODIFY | Summary: The lipid-metabolism keyword can be refined to long-chain fatty acid metabolism. Reason: ACSL4 directly activates long-chain fatty acids. GO:0001676 conveys the demonstrated substrate-level process more precisely than the broad lipid-metabolism mapping. Propagation Review Root cause: TERM SCOPING PROBLEM Failure modes: GRANULARITY MISMATCH Sources checked: UniProtKB-KW:KW-0443 SUPPORTS TRANSFER The lipid-metabolism keyword is true but broad; long-chain fatty-acid metabolism is a supported refinement. Proposed replacements: long-chain fatty acid metabolic process Supporting Evidence: PMID:9598324 The cDNA encodes a functional long-chain fatty acid-CoA ligase that shows preference for arachidonic acid as substrate PMID:31061331 both ACSL4 variants preferred various kinds of highly unsaturated fatty acids (HUFAs), including docosahexaenoic acid (DHA), adrenic acid (docosatetraenoic acid) and eicosapentaenoic acid (EPA), as well as AA as a substrate |
| GO:0006631 fatty acid metabolic process | IEA GO_REF:0000043 | ACCEPT | Summary: ACSL4 directly participates in fatty acid metabolism. Reason: This broader pathway annotation is correct: ligation to CoA channels fatty acids into downstream lipid synthesis and degradation. Retain the keyword mapping alongside more specific independently supported terms. Propagation Review Root cause: NO FAILURE CORE Sources checked: UniProtKB-KW:KW-0276 SUPPORTS TRANSFER Fatty-acid metabolism keyword captures the direct acyl-CoA activation step. Supporting Evidence: PMID:9598324 The cDNA encodes a functional long-chain fatty acid-CoA ligase that shows preference for arachidonic acid as substrate |
| GO:0016874 ligase activity | IEA GO_REF:0000043 | MODIFY | Summary: The generic ligase annotation can be refined to fatty acid-CoA ligase activity. Reason: Direct human assays identify the reaction and long-chain fatty-acid substrates. Refinement to GO:0004467 preserves all established C20/C22 substrate activities, including arachidonate. Propagation Review Root cause: TERM SCOPING PROBLEM Failure modes: GRANULARITY MISMATCH Sources checked: UniProtKB-KW:KW-0436 SUPPORTS TRANSFER Ligase keyword is correct but underspecified; long-chain fatty acid-CoA ligase provides demonstrated specificity. Proposed replacements: long-chain fatty acid-CoA ligase activity Supporting Evidence: PMID:31061331 both ACSL4 variants preferred various kinds of highly unsaturated fatty acids (HUFAs), including docosahexaenoic acid (DHA), adrenic acid (docosatetraenoic acid) and eicosapentaenoic acid (EPA), as well as AA as a substrate |
| GO:0047676 arachidonate-CoA ligase activity | IEA GO_REF:0000120 | ACCEPT | Summary: EC 6.2.1.15 and RHEA:19713 correctly map ACSL4 to arachidonate-CoA ligase. Reason: The reaction-specific mappings agree with human arachidonate activation assays. Preference for arachidonate does not exclude EPA, DHA or adrenate. Propagation Review Root cause: NO FAILURE CORE Sources checked: RHEA:19713 SUPPORTS TRANSFER Reaction/EC definition matches arachidonate activation demonstrated for human ACSL4. EC:6.2.1.15 SUPPORTS TRANSFER Reaction/EC definition matches arachidonate activation demonstrated for human ACSL4. Supporting Evidence: PMID:9598324 The cDNA encodes a functional long-chain fatty acid-CoA ligase that shows preference for arachidonic acid as substrate PMID:31061331 both ACSL4 variants preferred various kinds of highly unsaturated fatty acids (HUFAs), including docosahexaenoic acid (DHA), adrenic acid (docosatetraenoic acid) and eicosapentaenoic acid (EPA), as well as AA as a substrate |
| GO:0005739 mitochondrion | IEA GO_REF:0000107 | ACCEPT | Summary: The mouse ortholog transfer to mitochondrion agrees with human localization. Reason: The donor is mouse Acsl4 (Q9QUJ7; ENSMUSP00000033634). Human mitochondrial fractionation corroborates organelle association. Retain the source annotation at mitochondrion resolution rather than rewriting it to the outer membrane. Propagation Review Root cause: NO FAILURE CORE Sources checked: UniProtKB:Q9QUJ7 SUPPORTS TRANSFER Mouse Acsl4 ortholog identity is established; independent human mitochondrial localization corroborates the organelle-level transfer. ensembl:ENSMUSP00000033634 SUPPORTS TRANSFER Mouse Acsl4 ortholog identity is established; independent human mitochondrial localization corroborates the organelle-level transfer. Supporting Evidence: PMID:38720107 ACSL4 was mainly located in outer membrane of mitochondria (OM) and IMS |
| GO:0006633 fatty acid biosynthetic process | IEA GO_REF:0000107 | ACCEPT | Summary: ACSL4 performs the fatty-acid activation step used to prime elongation. Reason: GO:0006633 includes fatty-acid elongation. Reactome R-HSA-548843 identifies ACSL4 itself as the arachidonate-activation catalyst, and parent R-HSA-75876 includes this activation in elongation. Thus ACSL4 performs a step of the annotated biosynthetic pathway, although it does not catalyze carbon-chain condensation. The exact experimental basis of the mouse donor annotation was not recovered; this acceptance rests on the positive human pathway evidence. Propagation Review Root cause: NO FAILURE CORE Sources checked: UniProtKB:Q9QUJ7 UNRESOLVED Mouse Acsl4 donor identity is established, but the exact donor experiment for fatty-acid biosynthesis was not recovered. Positive human Reactome activation-in-elongation evidence supports retaining the target assertion. ensembl:ENSMUSP00000033634 UNRESOLVED Mouse Acsl4 donor identity is established, but the exact donor experiment for fatty-acid biosynthesis was not recovered. Positive human Reactome activation-in-elongation evidence supports retaining the target assertion. Supporting Evidence: Reactome:R-HSA-548843 Acyl-CoA synthetase long-chain family member 4 (ACSL4) associated with the endoplasmic reticulum membrane catalyses the conjugation of arachidonate (AA) with CoA to form arachidonyl-CoA (AA-CoA) Reactome:R-HSA-75876 In humans, activation is catalyzed by one of five acyl-CoA synthetase long-chain (ACSL) enzymes Reactome:R-HSA-75876 Here the full two-carbon elongation cycle to form stearate from palmitate is annotated, as well as the activation and condensation steps for elongation of arachidonate |
| GO:0006631 fatty acid metabolic process | TAS Reactome:R-HSA-434313 | ACCEPT | Summary: The insulin-secretion pathway includes a direct fatty-acid metabolism step catalyzed by ACSL4. Reason: R-HSA-434313 places fatty-acid activation within intracellular lipid metabolism in beta cells. ACSL4 catalyzes that metabolic step; this broad metabolic annotation need not imply that ACSL4 is the insulin secretory machinery. Supporting Evidence: PMID:9598324 The cDNA encodes a functional long-chain fatty acid-CoA ligase that shows preference for arachidonic acid as substrate |
| GO:0035338 long-chain fatty-acyl-CoA biosynthetic process | TAS Reactome:R-HSA-75876 | ACCEPT | Summary: ACSL4 directly synthesizes long-chain fatty acyl-CoAs by fatty-acid activation. Reason: The activation reaction is explicitly included in R-HSA-75876, and the ACSL4-specific arachidonate event is R-HSA-548843. Production of C20 arachidonoyl-CoA fits GO:0035338, regardless of the longer downstream elongation products. Supporting Evidence: Reactome:R-HSA-548843 Acyl-CoA synthetase long-chain family member 4 (ACSL4) associated with the endoplasmic reticulum membrane catalyses the conjugation of arachidonate (AA) with CoA to form arachidonyl-CoA (AA-CoA) Reactome:R-HSA-75876 In humans, activation is catalyzed by one of five acyl-CoA synthetase long-chain (ACSL) enzymes |
| GO:0090433 palmitoyl-CoA ligase activity | TAS Reactome:R-HSA-434382 | KEEP AS NON CORE | Summary: Palmitate activation is a reported secondary substrate activity. Reason: Retain the palmitoyl-CoA ligase event in R-HSA-434382. The original rat enzyme study reports low affinity for palmitate relative to arachidonate/EPA, rather than absence of palmitate turnover. The activity is secondary to the better-established PUFA preference. Supporting Evidence: PMID:9096315 the enzyme has a high affinity for arachidonate and eicosapentaenoate and low affinity for palmitate |
| GO:0005741 mitochondrial outer membrane | TAS Reactome:R-HSA-434382 | ACCEPT | Summary: Reactome locates the beta-cell ACSL3/4 activation reaction at the mitochondrial outer membrane. Reason: Retain this event-specific location, independently supported for human ACSL4 by the mitochondrial subfractionation study. It should not be generalized into a single obligatory location for all ACSL4. Supporting Evidence: PMID:38720107 ACSL4 was mainly located in outer membrane of mitochondria (OM) and IMS |
| GO:0005789 endoplasmic reticulum membrane | TAS Reactome:R-HSA-548843 | ACCEPT | Summary: The arachidonate activation reaction occurs at ER-associated ACSL4. Reason: R-HSA-548843 explicitly assigns ACSL4 as the ER-associated catalyst, supported independently by endogenous human-cell localization. Supporting Evidence: Reactome:R-HSA-548843 Acyl-CoA synthetase long-chain family member 4 (ACSL4) associated with the endoplasmic reticulum membrane catalyses the conjugation of arachidonate (AA) with CoA to form arachidonyl-CoA (AA-CoA) PMID:29450800 the ACSL4 localisation pattern more closely followed that of calnexin which is an endoplasmic reticulum resident chaperone |
| GO:0004467 long-chain fatty acid-CoA ligase activity | EXP PMID:11889465 FACL4, encoding fatty acid-CoA ligase 4, is mutated in nonsp... | ACCEPT | Summary: Patient-cell activity assays support ACSL4 fatty acid-CoA ligase function. Reason: The cached original abstract directly reports reduced enzymatic activity in affected human lymphoblastoid cells. This agrees with independent recombinant human assays. Retain the general catalytic term without inferring which >22-carbon substrate was assayed. Supporting Evidence: PMID:11889465 Analysis of enzymatic activity in lymphoblastoid cell lines from affected individuals of both families revealed low levels compared with normal cells PMID:9598324 The cDNA encodes a functional long-chain fatty acid-CoA ligase that shows preference for arachidonic acid as substrate |
| GO:0004467 long-chain fatty acid-CoA ligase activity | EXP PMID:12525535 A third MRX family (MRX68) is the result of mutation in the ... | ACCEPT | Summary: The P375L patient variant markedly reduces FACL4 enzymatic activity. Reason: The result-bearing abstract statement supports the experimental enzyme annotation. The paper title alone is not an enzyme-assay result. Supporting Evidence: PMID:12525535 changes a highly conserved proline into a leucine (p.P375L) in the first luciferase domain, which markedly reduces the enzymatic activity |
| GO:0004467 long-chain fatty acid-CoA ligase activity | IDA PMID:27842070 ACSL4 dictates ferroptosis sensitivity by shaping cellular l... | ACCEPT | Summary: ACSL4-mediated fatty-acid activation underlies the lipid remodeling tested in the ferroptosis study. Reason: The cited study identifies ACSL4 and its PUFA-dependent membrane remodeling; direct human enzyme studies independently establish the long-chain fatty acid-CoA ligase activity. Retain the curator-assigned IDA without inventing assay conditions from the abstract. Supporting Evidence: PMID:27842070 Mechanistically, ACSL4 enriched cellular membranes with long polyunsaturated Ο6 fatty acids PMID:31061331 both ACSL4 variants preferred various kinds of highly unsaturated fatty acids (HUFAs), including docosahexaenoic acid (DHA), adrenic acid (docosatetraenoic acid) and eicosapentaenoic acid (EPA), as well as AA as a substrate |
| GO:0004467 long-chain fatty acid-CoA ligase activity | IDA PMID:31061331 Analysis on the Substrate Specificity of Recombinant Human A... | ACCEPT | Summary: Recombinant human ACSL4 variants activate several highly unsaturated fatty acids. Reason: The full publisher article reports human variants expressed in Sf9 cells, partially purified, and assayed by LC-MS/MS for acyl-CoA formation. AA and EPA (C20) and DHA/adrenate (C22) fit the 13-22-carbon scope of GO:0004467. The use of insect expression cells does not make the assayed enzyme an insect ortholog. Supporting Evidence: PMID:31061331 both ACSL4 variants preferred various kinds of highly unsaturated fatty acids (HUFAs), including docosahexaenoic acid (DHA), adrenic acid (docosatetraenoic acid) and eicosapentaenoic acid (EPA), as well as AA as a substrate |
| GO:0004467 long-chain fatty acid-CoA ligase activity | IDA PMID:35027735 PKCΞ²II phosphorylates ACSL4 to amplify lipid peroxidation to... | ACCEPT | Summary: The PKCbetaII study measures activation of ACSL4-dependent lipid synthesis. Reason: The cached primary abstract explicitly describes phosphorylation and activation of ACSL4 and consequent PUFA-containing lipid biosynthesis. Retain the curator-assigned enzyme activity, also supported by direct recombinant human ACSL4 assays. ACSL4 is the kinase substrate, not the kinase. Supporting Evidence: PMID:35027735 activated ACSL4 catalyses polyunsaturated fatty acid-containing lipid biosynthesis and promotes the accumulation of lipid peroxidation products, leading to ferroptosis PMID:31061331 both ACSL4 variants preferred various kinds of highly unsaturated fatty acids (HUFAs), including docosahexaenoic acid (DHA), adrenic acid (docosatetraenoic acid) and eicosapentaenoic acid (EPA), as well as AA as a substrate |
| GO:0004467 long-chain fatty acid-CoA ligase activity | IDA PMID:38720107 Tumor-repopulating cells evade ferroptosis via PCK2-dependen... | ACCEPT | Summary: Purified human-cell ACSL4 catalyzes arachidonoyl-CoA formation. Reason: The full study measures AA-d8-CoA formation by ACSL4 purified from HONE1 cells and assays recombinant constructs purified from HEK293T cells. This is direct product-based ligase evidence. Supporting Evidence: PMID:38720107 enzyme activity assay indicated that ACSL4 from TRCs resulted in a lower product (AA-d8-CoA) formation than those from bulk tumor cells |
| GO:0005741 mitochondrial outer membrane | IDA PMID:38720107 Tumor-repopulating cells evade ferroptosis via PCK2-dependen... | ACCEPT | Summary: Human tumor-cell ACSL4 is present at the mitochondrial outer membrane. Reason: The full primary study reports ACSL4 localization by mitochondrial fractionation, immunoelectron microscopy and imaging. The quoted outer-membrane result supports the annotation; a generic statement about the interacting kinase PCK2 would not. Supporting Evidence: PMID:38720107 ACSL4 was mainly located in outer membrane of mitochondria (OM) and IMS |
| GO:0047676 arachidonate-CoA ligase activity | IDA PMID:31061331 Analysis on the Substrate Specificity of Recombinant Human A... | ACCEPT | Summary: Both recombinant human ACSL4 variants activate arachidonate. Reason: LC-MS/MS acyl-CoA assays in the full publisher article establish arachidonate activity while also showing substantial activity with other HUFAs. The specific annotation is valid without implying exclusive substrate specificity. Supporting Evidence: PMID:31061331 both ACSL4 variants preferred various kinds of highly unsaturated fatty acids (HUFAs), including docosahexaenoic acid (DHA), adrenic acid (docosatetraenoic acid) and eicosapentaenoic acid (EPA), as well as AA as a substrate |
| GO:0160020 positive regulation of ferroptosis | IDA PMID:27842070 ACSL4 dictates ferroptosis sensitivity by shaping cellular l... | ACCEPT | Summary: ACSL4 promotes ferroptosis by supplying activated PUFAs for susceptible membrane lipids. Reason: The original knockout/resistance and lipid-composition study supports positive regulation of ferroptosis. This is a functional role of ACSL4-catalyzed lipid remodeling, not a claim that ACSL4 is indispensable for every ferroptosis trigger or cell type. Supporting Evidence: PMID:27842070 Mechanistically, ACSL4 enriched cellular membranes with long polyunsaturated Ο6 fatty acids |
| GO:0160020 positive regulation of ferroptosis | IDA PMID:35027735 PKCΞ²II phosphorylates ACSL4 to amplify lipid peroxidation to... | ACCEPT | Summary: Activation of ACSL4 amplifies lipid peroxidation and ferroptosis. Reason: The cited study links ACSL4 activation to PUFA-containing lipid synthesis, lipid-peroxidation products and ferroptosis. This supports the direction of the positive-regulation annotation. Supporting Evidence: PMID:35027735 activated ACSL4 catalyses polyunsaturated fatty acid-containing lipid biosynthesis and promotes the accumulation of lipid peroxidation products, leading to ferroptosis |
| GO:0160020 positive regulation of ferroptosis | IDA PMID:38720107 Tumor-repopulating cells evade ferroptosis via PCK2-dependen... | ACCEPT | Summary: ACSL4 activity controls ferroptosis susceptibility through phospholipid remodeling. Reason: The full human tumor-cell study combines ACSL4 depletion/rescue, activity assays and phospholipid/ferroptosis measurements. PCK2 phosphorylates and activates ACSL4; reduced PCK2 expression in tumor-repopulating cells lowers ACSL4 activity and susceptible lipid pools. Active ACSL4 promotes ferroptosis in this context. Supporting Evidence: PMID:38720107 mitochondria metabolic kinase PCK2 phosphorylates and activates ACSL4 to drive ferroptosis-associated phospholipid remodeling |
| GO:0005739 mitochondrion | HTP PMID:34800366 Quantitative high-confidence human mitochondrial proteome an... | ACCEPT | Summary: Retain the mitochondrial organelle-level proteomics annotation. Reason: The MitoCoP study provides a human mitochondrial proteome, although the ACSL4-specific supplementary row was not independently extracted here. Defer to the curated HTP assignment, independently corroborated by human mitochondrial fractionation in PMID:38720107. Do not increase the source resolution to outer membrane. Supporting Evidence: PMID:38720107 ACSL4 was mainly located in outer membrane of mitochondria (OM) and IMS |
| GO:0001676 long-chain fatty acid metabolic process | IMP PMID:22633490 The SjΓΆgren-Larsson syndrome gene encodes a hexadecenal dehy... | ACCEPT | Summary: ACSL4 activates a long-chain fatty acid intermediate in sphingolipid-to-glycerolipid metabolism. Reason: The original abstract explicitly includes mammalian ACSL family members. The subsequent full primary paper PMID:24269233 identifies human ACSL4 among the previously tested complementing enzymes. The ALDH3A2-focused title does not negate these ACSL experiments. Supporting Evidence: PMID:22633490 yeast Faa1 and Faa4 and mammalian ACSL family members are acyl-CoA synthetases involved in the sphingolipid-to-glycerolipid metabolic pathway PMID:24269233 in addition to the previously identified ACSL family members (ACSL1, 3, 4, 5, and 6), we found that ACSVL1, ACSVL4, and ACSBG1 also restored metabolism |
| GO:0001676 long-chain fatty acid metabolic process | IDA PMID:24269233 Identification of acyl-CoA synthetases involved in the mamma... | ACCEPT | Summary: Human ACSL4 restores the fatty-acid activation step of the sphingolipid-to-glycerophospholipid pathway. Reason: The full author manuscript tests human constructs in yeast lacking FAA1 and FAA4, including ACSL4 variants. This heterologous complementation supports participation through long-chain fatty-acid activation; it is not evidence that ACSL4 cleaves sphingosine itself. Supporting Evidence: PMID:24269233 in addition to the previously identified ACSL family members (ACSL1, 3, 4, 5, and 6), we found that ACSVL1, ACSVL4, and ACSBG1 also restored metabolism |
| GO:0004467 long-chain fatty acid-CoA ligase activity | IMP PMID:22633490 The SjΓΆgren-Larsson syndrome gene encodes a hexadecenal dehy... | ACCEPT | Summary: The cited complementation work supports ACSL4 acyl-CoA synthetase activity. Reason: PMID:22633490 includes mammalian ACSL-family experiments, and the authors explicitly identify prior ACSL4 complementation in PMID:24269233. Independent human recombinant assays establish the same molecular function. Retain the IMP annotation without replacing it with a yeast-only observation. Supporting Evidence: PMID:22633490 yeast Faa1 and Faa4 and mammalian ACSL family members are acyl-CoA synthetases involved in the sphingolipid-to-glycerolipid metabolic pathway PMID:24269233 in addition to the previously identified ACSL family members (ACSL1, 3, 4, 5, and 6), we found that ACSVL1, ACSVL4, and ACSBG1 also restored metabolism PMID:31061331 both ACSL4 variants preferred various kinds of highly unsaturated fatty acids (HUFAs), including docosahexaenoic acid (DHA), adrenic acid (docosatetraenoic acid) and eicosapentaenoic acid (EPA), as well as AA as a substrate |
| GO:0004467 long-chain fatty acid-CoA ligase activity | IDA PMID:24269233 Identification of acyl-CoA synthetases involved in the mamma... | ACCEPT | Summary: Human ACSL4 supplies acyl-CoA synthetase activity in the functional complementation assay. Reason: The full manuscript describes human ACSL4 constructs restoring the pathway in a yeast double mutant lacking its activating enzymes. Retain the seeded IDA annotation; the assay host and expressed human gene product are distinct. Supporting Evidence: PMID:24269233 in addition to the previously identified ACSL family members (ACSL1, 3, 4, 5, and 6), we found that ACSVL1, ACSVL4, and ACSBG1 also restored metabolism |
| GO:0032024 positive regulation of insulin secretion | ISS GO_REF:0000024 | KEEP AS NON CORE | Summary: The ortholog-supported effect on glucose-stimulated insulin secretion is contextual. Reason: The donor is rat Acsl4 (UniProtKB:O35547), not mouse. Rat insulinoma-cell knockdown experiments support a positive effect on stimulated insulin secretion; the human UniProt record explicitly labels this function by similarity to O35547. Retain the transfer as a beta-cell context downstream of ACSL4 lipid metabolism, without claiming a direct insulin-release activity. Propagation Review Root cause: NO FAILURE NON CORE Sources checked: UniProtKB:O35547 SUPPORTS TRANSFER O35547 is rat Acsl4. PMID:23766516 reports knockdown in rat INS 832/13 cells with reduced glucose-stimulated and fatty-acid-potentiated insulin secretion; the human UniProt statement is explicitly by similarity. This is retained as a contextual process, not a direct human-cell assay. Supporting Evidence: PMID:23766516 an 80% suppression of Acsl4 decreased GSIS and FA-potentiated GSIS by 32 and 54%, respectively. |
| GO:0044233 mitochondria-associated endoplasmic reticulum membrane contact site | IDA PMID:23455425 Autophagosomes form at ER-mitochondria contact sites. | ACCEPT | Summary: A minor ACSL4 pool localizes to mitochondria-associated ER membranes in MCF-7 cells. Reason: Cached full PMID:29450800 directly detects a minor ACSL4 pool in the MAM fraction isolated from human MCF-7 cells (Figure 6 and associated Results). ACSL4 also occupies non-MAM ER, and the authors caution that it is not a useful universal MAM marker. This independent human result supports the contact-site location without implying exclusive MAM residency or an autophagy function. The external HEK293 fractionation from the original PMID:23455425 provides corroboration, with its access route recorded in notes. Supporting Evidence: PMID:29450800 ACSL4 partially localises to MAM. MAM, cytoplasmic and mitochondrial fractions, were prepared from MCF-7 cells. PMID:29450800 only a minor fraction of ACSL4 was present in the isolated MAM fraction with the bulk of the cellular compliment found in the cytoplasmic fraction |
| GO:0016020 membrane | HDA PMID:19946888 Defining the membrane proteome of NK cells. | ACCEPT | Summary: The membrane-proteome annotation is compatible with ACSL4 membrane association. Reason: The source analyzed membrane preparations from human NK-like YTS cells, including stably and transiently associated proteins. Retain its broad membrane resolution, supported independently by human ACSL4 localization. This assay does not identify ER specifically or establish integral membrane topology. Supporting Evidence: PMID:29450800 the ACSL4 localisation pattern more closely followed that of calnexin which is an endoplasmic reticulum resident chaperone |
| GO:0070062 extracellular exosome | HDA PMID:19056867 Large-scale proteomics and phosphoproteomics of urinary exos... | UNDECIDED | Summary: The ACSL4-specific urinary-exosome detection remains unverified. Reason: The cached original abstract describes the 1132-protein survey, but the full ACSL4 identification and its supporting dataset were not recovered. Preserve the curator-supplied HDA assertion and leave the review undecided. The available evidence establishes neither a core exosomal role nor contamination. |
| GO:0070062 extracellular exosome | HDA PMID:20458337 MHC class II-associated proteins in B-cell exosomes and pote... | UNDECIDED | Summary: The ACSL4-specific B-cell-exosome detection remains unverified. Reason: The cached abstract describes the exosome proteome and MHC-II-associated subset, but the ACSL4-specific identification was not inspected in the full study. Leave undecided rather than equating detection with a functional exosome role or dismissing it as incidental contamination. |
| GO:0005811 lipid droplet | IDA PMID:14741744 Identification of major proteins in the lipid droplet-enrich... | ACCEPT | Summary: Retain the curated ACSL4 lipid-droplet localization in HuH7 cells. Reason: The cached abstract emphasizes the abundant ACSL3 hit and does not list all lipid-metabolizing proteins. It cannot establish a paralog error. The authors subsequently explicitly report ACSL4 alongside the more abundant ACSL3 in droplets (primary follow-up route in notes). Defer to the original IDA assignment for this compatible localization while recording the incomplete access to the original full study. |
| GO:0031957 very long-chain fatty acid-CoA ligase activity | IMP PMID:11889465 FACL4, encoding fatty acid-CoA ligase 4, is mutated in nonsp... | UNDECIDED | Summary: The >22-carbon fatty acid-CoA ligase activity cannot be resolved from the accessible patient-study evidence. Reason: GO:0031957 requires a fatty acid with more than 22 carbons. The original full patient paper was not recovered, and its abstract reports reduced enzyme activity without naming the assay substrate. Independently, the purified rat ACS4 panel in PMID:9096315 tested C8-C22 saturated and C14-C22 unsaturated fatty acids; it supplies no test above C22. Human recombinant DHA/adrenate activity also reaches C22. These bounded assays neither establish nor exclude activity above C22, and they do not identify the patient-study substrate. Keep the experimental annotation intact and leave the decision unresolved. Supporting Evidence: PMID:11889465 Analysis of enzymatic activity in lymphoblastoid cell lines from affected individuals of both families revealed low levels compared with normal cells PMID:9096315 The purified enzyme utilizes arachidonate and eicosapentaenoate most preferentially among C8-C22 saturated fatty acids and C14-C22 unsaturated fatty acids. |
| GO:0005737 cytoplasm | IDA PMID:11889465 FACL4, encoding fatty acid-CoA ligase 4, is mutated in nonsp... | ACCEPT | Summary: Cytoplasmic localization is compatible with ACSL4 association with cytoplasmic organelles. Reason: GO:0005737 includes subcellular structures outside the nucleus and plasma membrane; it does not mean soluble cytosol. Retain the curated broad location, corroborated by independently observed ER and mitochondrial pools. No unobserved processing intermediate is needed to explain it, and the patient-study image resolution is not increased. Supporting Evidence: PMID:29450800 the ACSL4 localisation pattern more closely followed that of calnexin which is an endoplasmic reticulum resident chaperone PMID:38720107 ACSL4 was mainly located in outer membrane of mitochondria (OM) and IMS |
| GO:0006629 lipid metabolic process | IDA PMID:9598324 Cloning, expression, and chromosomal localization of human l... | MODIFY | Summary: The cloned human enzyme directly performs long-chain fatty acid metabolism. Reason: The original cloning study reports functional long-chain fatty acid-CoA ligase with arachidonate preference. Refine the very broad lipid-metabolic process to GO:0001676 using that positive biochemical evidence. Proposed replacements: long-chain fatty acid metabolic process Supporting Evidence: PMID:9598324 The cDNA encodes a functional long-chain fatty acid-CoA ligase that shows preference for arachidonic acid as substrate |
| GO:0047676 arachidonate-CoA ligase activity | IDA PMID:9598324 Cloning, expression, and chromosomal localization of human l... | ACCEPT | Summary: The original human FACL4 clone encodes an arachidonate-preferring ligase. Reason: The abstract explicitly reports a functional human long-chain fatty acid-CoA ligase with arachidonate preference. This directly supports the substrate-specific catalytic annotation. Supporting Evidence: PMID:9598324 The cDNA encodes a functional long-chain fatty acid-CoA ligase that shows preference for arachidonic acid as substrate |
| GO:0004467 long-chain fatty acid-CoA ligase activity | IDA PMID:10669417 Roles of PLC-beta2 and -beta3 and PI3Kgamma in chemoattracta... | ACCEPT | Summary: The molecular function is established, while support from this particular source remains unverified. Reason: Retain the curator-assigned activity because independent human cloning and recombinant assays conclusively establish it. The cached PMID:10669417 abstract concerns PLC/PI3K signaling in mice, but the full paper was not recovered; this is insufficient to declare a miscitation or paralog error. The original reference and evidence code are preserved and its reference review records the unresolved source attribution. Supporting Evidence: PMID:9598324 The cDNA encodes a functional long-chain fatty acid-CoA ligase that shows preference for arachidonic acid as substrate PMID:31061331 both ACSL4 variants preferred various kinds of highly unsaturated fatty acids (HUFAs), including docosahexaenoic acid (DHA), adrenic acid (docosatetraenoic acid) and eicosapentaenoic acid (EPA), as well as AA as a substrate |
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Download this section (compressed HTML)Q: What are the relative contributions of ACSL4 versus other ACSL family members to ferroptosis in different tissue contexts?
Q: Does ACSL4's role in neuronal function relate primarily to ferroptosis or to other lipid-dependent processes?
Experiment: Lipidomic analysis comparing AA-CoA and AdA-CoA levels in ACSL4 knockout versus wild-type cells across different tissue types. This would quantify the specific contribution of ACSL4 to PUFA-CoA pools in different cellular contexts.
Hypothesis: ACSL4 is the primary source of AA-CoA and AdA-CoA in ferroptosis-sensitive tissues
Experiment: Structure-function analysis of ACSL4 disease-causing mutations to understand substrate specificity determinants. This would inform both disease mechanisms and potential therapeutic interventions.
Hypothesis: Disease mutations affect substrate binding or catalytic efficiency
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