Existing Annotations Review

GO Term	Evidence	Action	Reason
GO:0047184 1-acylglycerophosphocholine O-acyltransferase activity	IBA GO_REF:0000033	ACCEPT	Summary: This is the core enzymatic activity of LPCAT3 (LPCAT = lysophosphatidylcholine acyltransferase). LPCAT3 catalyzes the transfer of acyl groups from acyl-CoA to 1-acyl-lysophosphatidylcholine to form phosphatidylcholine. This activity has been demonstrated directly in multiple biochemical studies (PMID:18195019, PMID:18772128, PMID:18782225). Reason: This is the primary named enzymatic activity of LPCAT3. Multiple independent studies have demonstrated this activity experimentally. Zhao et al. 2008 showed that "Membranes from HEK293 cells overexpressing LPCAT3 showed significantly increased LPCAT activity" (PMID:18195019). Gijon et al. 2008 confirmed "MBOAT5 prefers lysophosphatidylcholine and lyso-PS to incorporate linoleoyl and arachidonoyl chains" (PMID:18772128). The IBA annotation is phylogenetically supported and consistent with all biochemical evidence. Supporting Evidence: PMID:18195019 Membranes from HEK293 cells overexpressing LPCAT3 showed significantly increased LPCAT activity as assessed by thin layer chromatography analysis with substrate preference toward unsaturated fatty acids. PMID:18772128 MBOAT5 prefers lysophosphatidylcholine and lyso-PS to incorporate linoleoyl and arachidonoyl chains. file:human/LPCAT3/LPCAT3-deep-research-falcon.md model: Edison Scientific Literature
GO:0047184 1-acylglycerophosphocholine O-acyltransferase activity	IEA GO_REF:0000120	ACCEPT	Summary: IEA annotation for the core LPCAT activity based on UniProt mapping and RHEA reaction cross-references. This duplicates the IBA annotation but from a computational source. Reason: This is the core enzymatic function of LPCAT3, well-supported by experimental evidence from multiple sources. The IEA mapping is consistent with experimental data. Supporting Evidence: PMID:18195019 LPCAT3 belongs to the membrane-bound O-acyltransferase (MBOAT) family and encodes a protein of 487 amino acids... LPCAT3 is primarily responsible for hepatic LPCAT activity.
GO:0047184 1-acylglycerophosphocholine O-acyltransferase activity	IDA PMID:18782225 Member of the membrane-bound O-acyltransferase (MBOAT) famil...	ACCEPT	Summary: Direct biochemical demonstration of LPCAT activity by Matsuda et al. 2008. Over-expression of MBOAT5 in HEK293 cells resulted in great increases in LPC acyltransferase activity using arachidonoyl-CoA as donor. Reason: Direct experimental evidence from reconstitution studies in HEK293 cells showing LPCAT activity is strongly increased upon MBOAT5/LPCAT3 overexpression. Supporting Evidence: PMID:18782225 Conversely, over-expression of MBOAT5 in human embryonic kidney (HEK) 293 cells resulted in great increases in LPC, LPS and LPE acyltransferase activities but not in LPIAT or lysophosphatidic acid (LPA) acyltransferase (LPAAT) activities.
GO:0047184 1-acylglycerophosphocholine O-acyltransferase activity	IDA PMID:18195019 Identification and characterization of a major liver lysopho...	ACCEPT	Summary: Zhao et al. 2008 identified LPCAT3 as the major liver LPCAT and characterized its enzymatic activity with various acyl-CoA substrates, showing preference for unsaturated fatty acids. Reason: Key primary study identifying LPCAT3 and demonstrating its enzymatic activity directly. Shows LPCAT3 is the major hepatic LPCAT enzyme. Supporting Evidence: PMID:18195019 In a human hepatoma Huh7 cells, RNA interference-mediated knockdown of LPCAT3 resulted in virtually complete loss of membrane LPCAT activity, suggesting that LPCAT3 is primarily responsible for hepatic LPCAT activity.
GO:0047184 1-acylglycerophosphocholine O-acyltransferase activity	IDA PMID:18772128 Lysophospholipid acyltransferases and arachidonate recycling...	ACCEPT	Summary: Gijon et al. 2008 used mass spectrometry-based enzyme assays to characterize MBOAT5/LPCAT3 substrate specificity, showing preference for LPC with linoleoyl and arachidonoyl donors. Reason: High-quality biochemical characterization using novel MS-based assays confirming LPC acyltransferase activity with PUFA preference. Supporting Evidence: PMID:18772128 MBOAT5 prefers lysophosphatidylcholine and lyso-PS to incorporate linoleoyl and arachidonoyl chains.
GO:0047184 1-acylglycerophosphocholine O-acyltransferase activity	IMP PMID:22511767 Lysophosphatidylcholine acyltransferase 3 knockdown-mediated...	ACCEPT	Summary: Li et al. 2012 showed that LPCAT3 knockdown significantly reduces hepatic LPCAT activity, providing mutant phenotype evidence for this molecular function. Reason: Important study confirming LPCAT3 as the major hepatic LPCAT isoform through knockdown experiments showing loss of enzymatic activity. Supporting Evidence: PMID:22511767 We found that LPCAT3 is the major hepatic isoform, and its knockdown significantly reduces hepatic LPCAT activity.
GO:0071617 lysophospholipid acyltransferase activity	IBA GO_REF:0000033	ACCEPT	Summary: LPCAT3 is indeed a lysophospholipid acyltransferase with broad substrate specificity encompassing LPC, LPE, and LPS. This broader term correctly captures the enzyme's range of substrates. Reason: Appropriate parent term that accurately reflects the enzyme's activity on multiple lysophospholipid substrates. Matsuda et al. 2008 demonstrated that MBOAT5 "is a lysophospholipid acyltransferase acting preferentially on LPC, LPS and LPE" (PMID:18782225). Supporting Evidence: PMID:18782225 These results indicate that human MBOAT5 is a lysophospholipid acyltransferase acting preferentially on LPC, LPS and LPE.
GO:0106262 1-acylglycerophosphoethanolamine O-acyltransferase activity	IEA GO_REF:0000120	ACCEPT	Summary: LPCAT3 has documented LPEAT activity, transferring acyl groups to lysophosphatidylethanolamine. This is a secondary but well-characterized activity. Reason: LPEAT activity has been experimentally demonstrated, though it is lower than LPCAT activity. UniProt assigns EC 2.3.1.n7 for this activity based on PMID:18772128 and PMID:18782225. Supporting Evidence: PMID:18772128 Human neutrophils express mRNA for these four enzymes, and neutrophil microsomes incorporate arachidonoyl chains into phosphatidylinositol, phosphatidylcholine, PS, and phosphatidylethanolamine in a thimerosal-sensitive manner.
GO:0106262 1-acylglycerophosphoethanolamine O-acyltransferase activity	ISS GO_REF:0000024	ACCEPT	Summary: ISS annotation for LPEAT activity based on mouse ortholog data. Reason: Sequence similarity annotation is consistent with direct experimental evidence for this activity in human LPCAT3. Supporting Evidence: PMID:18782225 Conversely, over-expression of MBOAT5 in human embryonic kidney (HEK) 293 cells resulted in great increases in LPC, LPS and LPE acyltransferase activities but not in LPIAT or lysophosphatidic acid (LPA) acyltransferase (LPAAT) activities.
GO:0106262 1-acylglycerophosphoethanolamine O-acyltransferase activity	IDA PMID:18772128 Lysophospholipid acyltransferases and arachidonate recycling...	ACCEPT	Summary: Direct demonstration of LPEAT activity by Gijon et al. 2008 using MS-based enzyme assays. Reason: Direct experimental evidence showing MBOAT5/LPCAT3 can acylate LPE, though this is a secondary activity compared to LPC. Supporting Evidence: PMID:18772128 Human neutrophils express mRNA for these four enzymes, and neutrophil microsomes incorporate arachidonoyl chains into phosphatidylinositol, phosphatidylcholine, PS, and phosphatidylethanolamine in a thimerosal-sensitive manner.
GO:0106262 1-acylglycerophosphoethanolamine O-acyltransferase activity	IDA PMID:18782225 Member of the membrane-bound O-acyltransferase (MBOAT) famil...	ACCEPT	Summary: Matsuda et al. 2008 demonstrated LPE acyltransferase activity through overexpression studies in HEK293 cells. Reason: Direct experimental evidence confirming LPEAT activity of MBOAT5/LPCAT3. Supporting Evidence: PMID:18782225 Conversely, over-expression of MBOAT5 in human embryonic kidney (HEK) 293 cells resulted in great increases in LPC, LPS and LPE acyltransferase activities but not in LPIAT or lysophosphatidic acid (LPA) acyltransferase (LPAAT) activities.
GO:0106263 1-acylglycerophosphoserine O-acyltransferase activity	IEA GO_REF:0000120	ACCEPT	Summary: LPCAT3 has documented LPSAT activity, acylating lysophosphatidylserine. Reason: LPSAT activity is experimentally supported. UniProt assigns EC 2.3.1.n6 based on multiple experimental studies. Supporting Evidence: PMID:18782225 These results indicate that human MBOAT5 is a lysophospholipid acyltransferase acting preferentially on LPC, LPS and LPE.
GO:0106263 1-acylglycerophosphoserine O-acyltransferase activity	IDA PMID:18195019 Identification and characterization of a major liver lysopho...	ACCEPT	Summary: Zhao et al. 2008 demonstrated LPSAT activity in their characterization of LPCAT3. Reason: Direct experimental evidence for LPS acyltransferase activity. Supporting Evidence: PMID:18782225 These results indicate that human MBOAT5 is a lysophospholipid acyltransferase acting preferentially on LPC, LPS and LPE.
GO:0106263 1-acylglycerophosphoserine O-acyltransferase activity	IDA PMID:18772128 Lysophospholipid acyltransferases and arachidonate recycling...	ACCEPT	Summary: Gijon et al. 2008 confirmed LPS acyltransferase activity using MS-based assays. Reason: High-quality MS-based biochemical evidence for LPSAT activity. Supporting Evidence: PMID:18772128 MBOAT5 prefers lysophosphatidylcholine and lyso-PS to incorporate linoleoyl and arachidonoyl chains.
GO:0106263 1-acylglycerophosphoserine O-acyltransferase activity	IDA PMID:18782225 Member of the membrane-bound O-acyltransferase (MBOAT) famil...	ACCEPT	Summary: Matsuda et al. 2008 demonstrated LPS acyltransferase activity through overexpression studies. Reason: Direct experimental evidence for LPSAT activity. Supporting Evidence: PMID:18782225 Conversely, over-expression of MBOAT5 in human embryonic kidney (HEK) 293 cells resulted in great increases in LPC, LPS and LPE acyltransferase activities but not in LPIAT or lysophosphatidic acid (LPA) acyltransferase (LPAAT) activities.
GO:0003841 1-acylglycerol-3-phosphate O-acyltransferase activity	TAS Reactome:R-HSA-1482547	UNDECIDED	Summary: Reactome annotation for AGPAT-like activity. However, LPCAT3 acts on lysophospholipids (with headgroups like choline, ethanolamine, serine), not on lysophosphatidic acid (LPA). This activity is distinct from true AGPAT/LPAAT activity. Reason: This term refers to activity on 1-acylglycerol-3-phosphate (lysophosphatidic acid), which is different from the lysophospholipids that LPCAT3 prefers. Matsuda et al. 2008 explicitly showed that MBOAT5 overexpression did NOT increase LPAAT activity (PMID:18782225). The Reactome pathway may be capturing a related reaction step in phospholipid remodeling, but the GO term may be imprecise. Need to verify the exact Reactome reaction definition. Supporting Evidence: PMID:18782225 Conversely, over-expression of MBOAT5 in human embryonic kidney (HEK) 293 cells resulted in great increases in LPC, LPS and LPE acyltransferase activities but not in LPIAT or lysophosphatidic acid (LPA) acyltransferase (LPAAT) activities.
GO:0003841 1-acylglycerol-3-phosphate O-acyltransferase activity	TAS Reactome:R-HSA-1482636	UNDECIDED	Summary: Second Reactome annotation for AGPAT activity. Reason: Same concern as above - LPCAT3 lacks significant LPAAT activity according to direct biochemical studies. The Reactome pathway context needs verification. Supporting Evidence: PMID:18782225 Conversely, over-expression of MBOAT5 in human embryonic kidney (HEK) 293 cells resulted in great increases in LPC, LPS and LPE acyltransferase activities but not in LPIAT or lysophosphatidic acid (LPA) acyltransferase (LPAAT) activities.
GO:0003841 1-acylglycerol-3-phosphate O-acyltransferase activity	TAS Reactome:R-HSA-1482667	UNDECIDED	Summary: Third Reactome annotation for AGPAT activity. Reason: Same concern - experimental evidence suggests LPCAT3 does not have significant LPAAT activity. Supporting Evidence: PMID:18782225 Conversely, over-expression of MBOAT5 in human embryonic kidney (HEK) 293 cells resulted in great increases in LPC, LPS and LPE acyltransferase activities but not in LPIAT or lysophosphatidic acid (LPA) acyltransferase (LPAAT) activities.
GO:0047144 2-acylglycerol-3-phosphate O-acyltransferase activity	TAS Reactome:R-HSA-1482533	UNDECIDED	Summary: Reactome annotation for acyltransferase activity at the sn-1 position of 2-acyl-lysophospholipids. Reason: LPCAT3 primarily acts on 1-acyl-lysophospholipids (re-acylating at sn-2 position), not 2-acyl-lysophospholipids. This annotation may reflect a minor activity or may be pathway modeling that requires verification. Supporting Evidence: PMID:18195019 The reacylation step is catalyzed by lysophosphatidylcholine acyltransferase (LPCAT), and we report here the identification of a novel LPCAT, which we named LPCAT3.
GO:0047144 2-acylglycerol-3-phosphate O-acyltransferase activity	TAS Reactome:R-HSA-1482646	UNDECIDED	Summary: Second Reactome annotation for 2-AGPAT activity. Reason: Same concern - primary activity is on 1-acyl-lysophospholipids, not 2-acyl. Supporting Evidence: PMID:18195019 The reacylation step is catalyzed by lysophosphatidylcholine acyltransferase (LPCAT), and we report here the identification of a novel LPCAT, which we named LPCAT3.
GO:0047144 2-acylglycerol-3-phosphate O-acyltransferase activity	TAS Reactome:R-HSA-1482691	UNDECIDED	Summary: Third Reactome annotation for 2-AGPAT activity. Reason: Same concern regarding substrate specificity. Supporting Evidence: PMID:18195019 The reacylation step is catalyzed by lysophosphatidylcholine acyltransferase (LPCAT), and we report here the identification of a novel LPCAT, which we named LPCAT3.
GO:0016740 transferase activity	IEA GO_REF:0000043	MARK AS OVER ANNOTATED	Summary: Very general term for transferase activity based on UniProt keyword mapping. Reason: This term is too general to be informative. LPCAT3 has specific lysophospholipid acyltransferase activities that are captured by more specific terms (GO:0047184, GO:0071617, GO:0106262, GO:0106263). Proposed replacements: 1-acylglycerophosphocholine O-acyltransferase activity lysophospholipid acyltransferase activity
GO:0016746 acyltransferase activity	IEA GO_REF:0000043	MARK AS OVER ANNOTATED	Summary: General acyltransferase activity term from UniProt keyword mapping. Reason: This is a broad parent term that doesn't convey the specific substrate preference of LPCAT3. More informative terms exist (GO:0047184, GO:0071617). Proposed replacements: 1-acylglycerophosphocholine O-acyltransferase activity lysophospholipid acyltransferase activity
GO:0016020 membrane	IBA GO_REF:0000033	MODIFY	Summary: General membrane annotation. LPCAT3 is indeed membrane-localized but this term is too general. Reason: LPCAT3 is specifically localized to the endoplasmic reticulum membrane (PMID:18195019). The term "membrane" is too general; GO:0005789 (endoplasmic reticulum membrane) is more appropriate and already annotated. Proposed replacements: endoplasmic reticulum membrane Supporting Evidence: PMID:18195019 LPCAT3 is localized within the endoplasmic reticulum and is primarily expressed in metabolic tissues including liver, adipose, and pancreas.
GO:0005789 endoplasmic reticulum membrane	IEA GO_REF:0000120	ACCEPT	Summary: IEA annotation for ER membrane localization based on UniProt subcellular location mapping. Reason: This is the correct and specific localization for LPCAT3, confirmed by direct experimental evidence (PMID:18195019). Supporting Evidence: PMID:18195019 LPCAT3 is localized within the endoplasmic reticulum and is primarily expressed in metabolic tissues including liver, adipose, and pancreas.
GO:0005789 endoplasmic reticulum membrane	IDA PMID:18195019 Identification and characterization of a major liver lysopho...	ACCEPT	Summary: Direct experimental demonstration of ER localization by Zhao et al. 2008. Reason: Key primary evidence for ER localization from the study that identified LPCAT3 as the major liver LPCAT enzyme. Supporting Evidence: PMID:18195019 LPCAT3 is localized within the endoplasmic reticulum and is primarily expressed in metabolic tissues including liver, adipose, and pancreas.
GO:0005789 endoplasmic reticulum membrane	TAS Reactome:R-HSA-1482533	ACCEPT	Summary: Reactome annotation for ER membrane localization in context of PC acyl chain remodeling pathway. Reason: Consistent with direct experimental evidence for ER localization. Supporting Evidence: PMID:18195019 LPCAT3 is localized within the endoplasmic reticulum and is primarily expressed in metabolic tissues including liver, adipose, and pancreas.
GO:0005789 endoplasmic reticulum membrane	TAS Reactome:R-HSA-1482547	ACCEPT	Summary: Reactome annotation for ER membrane localization. Reason: Consistent with experimental evidence. Supporting Evidence: PMID:18195019 LPCAT3 is localized within the endoplasmic reticulum and is primarily expressed in metabolic tissues including liver, adipose, and pancreas.
GO:0005789 endoplasmic reticulum membrane	TAS Reactome:R-HSA-1482636	ACCEPT	Summary: Reactome annotation for ER membrane localization. Reason: Consistent with experimental evidence. Supporting Evidence: PMID:18195019 LPCAT3 is localized within the endoplasmic reticulum and is primarily expressed in metabolic tissues including liver, adipose, and pancreas.
GO:0005789 endoplasmic reticulum membrane	TAS Reactome:R-HSA-1482646	ACCEPT	Summary: Reactome annotation for ER membrane localization. Reason: Consistent with experimental evidence. Supporting Evidence: PMID:18195019 LPCAT3 is localized within the endoplasmic reticulum and is primarily expressed in metabolic tissues including liver, adipose, and pancreas.
GO:0005789 endoplasmic reticulum membrane	TAS Reactome:R-HSA-1482667	ACCEPT	Summary: Reactome annotation for ER membrane localization. Reason: Consistent with experimental evidence. Supporting Evidence: PMID:18195019 LPCAT3 is localized within the endoplasmic reticulum and is primarily expressed in metabolic tissues including liver, adipose, and pancreas.
GO:0005789 endoplasmic reticulum membrane	TAS Reactome:R-HSA-1482691	ACCEPT	Summary: Reactome annotation for ER membrane localization. Reason: Consistent with experimental evidence. Supporting Evidence: PMID:18195019 LPCAT3 is localized within the endoplasmic reticulum and is primarily expressed in metabolic tissues including liver, adipose, and pancreas.
GO:0016020 membrane	HDA PMID:19946888 Defining the membrane proteome of NK cells.	MODIFY	Summary: High-throughput proteomics study identified LPCAT3 in NK cell membrane preparations. Reason: While this term is general and the HDA evidence is from a membrane proteomics study, the more specific ER membrane term (GO:0005789) is preferred and already annotated. LPCAT3 is specifically localized to the ER membrane. Proposed replacements: endoplasmic reticulum membrane Supporting Evidence: PMID:19946888 Mass spectrometric analysis identified 1843 proteins with high confidence scores.
GO:0036152 phosphatidylethanolamine acyl-chain remodeling	IBA GO_REF:0000033	ACCEPT	Summary: LPCAT3 participates in PE acyl-chain remodeling as part of the Lands cycle through its LPEAT activity. Reason: LPCAT3 has demonstrated LPEAT activity (PMID:18772128, PMID:18782225), enabling it to participate in PE remodeling. This is a core function related to the Lands cycle. Supporting Evidence: PMID:18782225 Knockdown of a human mboa-6 homologue, referred to as MBOAT5, also impaired the incorporation of PUFAs into PC, PS and PE in HeLa cells.
GO:0036152 phosphatidylethanolamine acyl-chain remodeling	IEA GO_REF:0000107	ACCEPT	Summary: IEA annotation based on Ensembl Compara orthology to mouse. Reason: Consistent with direct experimental evidence for LPEAT activity. Supporting Evidence: PMID:18782225 Knockdown of a human mboa-6 homologue, referred to as MBOAT5, also impaired the incorporation of PUFAs into PC, PS and PE in HeLa cells.
GO:0036152 phosphatidylethanolamine acyl-chain remodeling	TAS Reactome:R-HSA-1482839	ACCEPT	Summary: Reactome pathway annotation for PE acyl-chain remodeling. Reason: Consistent with LPEAT activity of LPCAT3. Supporting Evidence: PMID:18782225 Knockdown of a human mboa-6 homologue, referred to as MBOAT5, also impaired the incorporation of PUFAs into PC, PS and PE in HeLa cells.
GO:0036152 phosphatidylethanolamine acyl-chain remodeling	IMP PMID:18782225 Member of the membrane-bound O-acyltransferase (MBOAT) famil...	ACCEPT	Summary: Matsuda et al. 2008 showed that MBOAT5 knockdown impairs PUFA incorporation into PE. Reason: Direct mutant phenotype evidence from knockdown experiments. Supporting Evidence: PMID:18782225 Knockdown of a human mboa-6 homologue, referred to as MBOAT5, also impaired the incorporation of PUFAs into PC, PS and PE in HeLa cells.
GO:0036152 phosphatidylethanolamine acyl-chain remodeling	IDA PMID:18772128 Lysophospholipid acyltransferases and arachidonate recycling...	ACCEPT	Summary: Gijon et al. 2008 demonstrated LPEAT activity in neutrophils. Reason: Direct biochemical evidence for PE remodeling activity. Supporting Evidence: PMID:18772128 Human neutrophils express mRNA for these four enzymes, and neutrophil microsomes incorporate arachidonoyl chains into phosphatidylinositol, phosphatidylcholine, PS, and phosphatidylethanolamine in a thimerosal-sensitive manner.
GO:0006656 phosphatidylcholine biosynthetic process	IBA GO_REF:0000033	ACCEPT	Summary: LPCAT3 contributes to PC biosynthesis through the Lands cycle remodeling pathway, converting LPC to PC. Reason: While the de novo Kennedy pathway is the primary biosynthetic route, the Lands cycle (which LPCAT3 catalyzes) is responsible for remodeling >50% of cellular PC and can be considered biosynthetic in the sense that it produces the final PC species. This is a core function. Supporting Evidence: PMID:18195019 Phosphatidylcholine (PC) is synthesized through the Kennedy pathway, but more than 50% of PC is remodeled through the Lands cycle, i.e. the deacylation and reacylation of PC to attain the final and proper fatty acids within PC.
GO:0030258 lipid modification	IBA GO_REF:0000033	ACCEPT	Summary: LPCAT3 modifies lipids by reacylating lysophospholipids. Reason: This is a correct general parent term for the acyl-chain remodeling activities of LPCAT3. The Lands cycle fundamentally involves lipid modification. Supporting Evidence: PMID:18195019 The reacylation step is catalyzed by lysophosphatidylcholine acyltransferase (LPCAT), and we report here the identification of a novel LPCAT, which we named LPCAT3.
GO:0036151 phosphatidylcholine acyl-chain remodeling	IEA GO_REF:0000107	ACCEPT	Summary: Core function of LPCAT3 in the Lands cycle - remodeling PC acyl chains. Reason: This is the primary biological process of LPCAT3. The enzyme remodels PC by incorporating PUFAs at the sn-2 position. Supporting Evidence: PMID:18195019 The reacylation step is catalyzed by lysophosphatidylcholine acyltransferase (LPCAT), and we report here the identification of a novel LPCAT, which we named LPCAT3.
GO:0036151 phosphatidylcholine acyl-chain remodeling	TAS Reactome:R-HSA-1482788	ACCEPT	Summary: Reactome pathway annotation for PC acyl-chain remodeling. Reason: Core function consistent with experimental evidence. Supporting Evidence: PMID:18195019 The reacylation step is catalyzed by lysophosphatidylcholine acyltransferase (LPCAT), and we report here the identification of a novel LPCAT, which we named LPCAT3.
GO:0036151 phosphatidylcholine acyl-chain remodeling	IMP PMID:18782225 Member of the membrane-bound O-acyltransferase (MBOAT) famil...	ACCEPT	Summary: Matsuda et al. 2008 showed knockdown of MBOAT5 reduced PUFA incorporation into PC. Reason: Direct mutant phenotype evidence for PC remodeling function. Supporting Evidence: PMID:18782225 Knockdown of a human mboa-6 homologue, referred to as MBOAT5, also impaired the incorporation of PUFAs into PC, PS and PE in HeLa cells.
GO:0036151 phosphatidylcholine acyl-chain remodeling	IDA PMID:18195019 Identification and characterization of a major liver lysopho...	ACCEPT	Summary: Zhao et al. 2008 directly demonstrated PC remodeling by LPCAT3. Reason: Key primary evidence for PC remodeling function. Supporting Evidence: PMID:18195019 In a human hepatoma Huh7 cells, RNA interference-mediated knockdown of LPCAT3 resulted in virtually complete loss of membrane LPCAT activity, suggesting that LPCAT3 is primarily responsible for hepatic LPCAT activity.
GO:0036151 phosphatidylcholine acyl-chain remodeling	IDA PMID:18772128 Lysophospholipid acyltransferases and arachidonate recycling...	ACCEPT	Summary: Gijon et al. 2008 demonstrated PC remodeling in neutrophils. Reason: Direct biochemical evidence for PC remodeling. Supporting Evidence: PMID:18772128 Human neutrophils express mRNA for these four enzymes, and neutrophil microsomes incorporate arachidonoyl chains into phosphatidylinositol, phosphatidylcholine, PS, and phosphatidylethanolamine in a thimerosal-sensitive manner.
GO:0036151 phosphatidylcholine acyl-chain remodeling	ISS GO_REF:0000024	ACCEPT	Summary: ISS annotation based on mouse ortholog. Reason: Consistent with direct experimental evidence. Supporting Evidence: PMID:18195019 LPCAT3 is primarily responsible for hepatic LPCAT activity.
GO:0036150 phosphatidylserine acyl-chain remodeling	IEA GO_REF:0000107	ACCEPT	Summary: LPCAT3 has LPSAT activity enabling PS remodeling. Reason: Consistent with demonstrated LPSAT activity (PMID:18195019, PMID:18772128, PMID:18782225). Supporting Evidence: PMID:18772128 MBOAT5 prefers lysophosphatidylcholine and lyso-PS to incorporate linoleoyl and arachidonoyl chains.
GO:0036150 phosphatidylserine acyl-chain remodeling	TAS Reactome:R-HSA-1482801	ACCEPT	Summary: Reactome pathway annotation for PS acyl-chain remodeling. Reason: Consistent with LPSAT activity. Supporting Evidence: PMID:18772128 MBOAT5 prefers lysophosphatidylcholine and lyso-PS to incorporate linoleoyl and arachidonoyl chains.
GO:0036150 phosphatidylserine acyl-chain remodeling	IMP PMID:18782225 Member of the membrane-bound O-acyltransferase (MBOAT) famil...	ACCEPT	Summary: Knockdown of MBOAT5 reduced PUFA incorporation into PS. Reason: Direct mutant phenotype evidence. Supporting Evidence: PMID:18782225 Knockdown of a human mboa-6 homologue, referred to as MBOAT5, also impaired the incorporation of PUFAs into PC, PS and PE in HeLa cells.
GO:0036150 phosphatidylserine acyl-chain remodeling	IDA PMID:18195019 Identification and characterization of a major liver lysopho...	ACCEPT	Summary: Zhao et al. 2008 demonstrated LPSAT activity. Reason: Direct biochemical evidence. Supporting Evidence: PMID:18782225 These results indicate that human MBOAT5 is a lysophospholipid acyltransferase acting preferentially on LPC, LPS and LPE.
GO:0036150 phosphatidylserine acyl-chain remodeling	IDA PMID:18772128 Lysophospholipid acyltransferases and arachidonate recycling...	ACCEPT	Summary: Gijon et al. 2008 demonstrated PS remodeling activity. Reason: Direct MS-based biochemical evidence. Supporting Evidence: PMID:18772128 MBOAT5 prefers lysophosphatidylcholine and lyso-PS to incorporate linoleoyl and arachidonoyl chains.
GO:0006629 lipid metabolic process	IEA GO_REF:0000043	MARK AS OVER ANNOTATED	Summary: Very general term for lipid metabolism from UniProt keyword mapping. Reason: This term is too general. More specific terms like GO:0036151 (phosphatidylcholine acyl-chain remodeling) better capture LPCAT3's function. Proposed replacements: phosphatidylcholine acyl-chain remodeling
GO:0008654 phospholipid biosynthetic process	IEA GO_REF:0000043	ACCEPT	Summary: LPCAT3 contributes to phospholipid production through the Lands cycle. Reason: While technically LPCAT3 is involved in remodeling rather than de novo biosynthesis, the Lands cycle produces the final phospholipid species with appropriate acyl chains. This general term is acceptable as a parent annotation. Supporting Evidence: PMID:18195019 Phosphatidylcholine (PC) is synthesized through the Kennedy pathway, but more than 50% of PC is remodeled through the Lands cycle, i.e. the deacylation and reacylation of PC to attain the final and proper fatty acids within PC.
GO:0006644 phospholipid metabolic process	IEA GO_REF:0000041	ACCEPT	Summary: General phospholipid metabolism term from UniPathway mapping. Reason: LPCAT3 is centrally involved in phospholipid metabolism through the Lands cycle. This is a correct general parent term. Supporting Evidence: PMID:18195019 Our studies identify a long-sought enzyme that plays a critical role in PC remodeling in metabolic tissues and provide an invaluable tool for future investigations on how PC remodeling may potentially impact glucose and lipid homeostasis.
GO:0034378 chylomicron assembly	IEA GO_REF:0000107	KEEP AS NON CORE	Summary: LPCAT3 in intestine provides PC for chylomicron surface assembly. Reason: While this is a documented physiological role in enterocytes (primarily from mouse studies), it is a downstream consequence of LPCAT3's core phospholipid remodeling function rather than the core molecular function. Intestine-specific Lpcat3 knockout in mice impairs chylomicron secretion. Supporting Evidence: PMID:22511767 Lipoprotein production studies indicated that reductions in LPCAT3 enhanced assembly and secretion of triglyceride-rich apoB-containing lipoproteins.
GO:0034378 chylomicron assembly	ISS GO_REF:0000024	KEEP AS NON CORE	Summary: ISS annotation based on mouse ortholog data. Reason: Downstream physiological consequence in intestine, not core molecular function. Supporting Evidence: PMID:22511767 Lipoprotein production studies indicated that reductions in LPCAT3 enhanced assembly and secretion of triglyceride-rich apoB-containing lipoproteins.
GO:0034379 very-low-density lipoprotein particle assembly	IEA GO_REF:0000107	KEEP AS NON CORE	Summary: LPCAT3 in liver provides PC for VLDL assembly. Reason: This is a downstream physiological consequence of LPCAT3's ER membrane PC remodeling activity. LPCAT3 knockdown affects VLDL production through altered LPC/PC levels and MTP expression (PMID:22511767). Supporting Evidence: PMID:22511767 Lipoprotein production studies indicated that reductions in LPCAT3 enhanced assembly and secretion of triglyceride-rich apoB-containing lipoproteins... hepatic LPCAT3 modulates VLDL production by regulating LysoPC levels and MTP expression.
GO:0034379 very-low-density lipoprotein particle assembly	ISS GO_REF:0000024	KEEP AS NON CORE	Summary: ISS annotation based on mouse ortholog. Reason: Downstream physiological consequence in liver, not core molecular function. Supporting Evidence: PMID:22511767 Hepatic LPCAT3 modulates VLDL production by regulating LysoPC levels and MTP expression.
GO:0036335 intestinal stem cell homeostasis	IEA GO_REF:0000107	KEEP AS NON CORE	Summary: Mouse studies suggest LPCAT3 regulates intestinal stem cell function through cholesterol metabolism. Reason: This is a pleiotropic downstream effect in intestine, not the core molecular function. Evidence comes primarily from mouse knockout studies showing LPCAT3 influences a dietary-responsive phospholipid-cholesterol axis affecting intestinal stem cells. Supporting Evidence: doi:10.1172/jci93616 LPCAT3 regulates ER phospholipid composition which modulates lipogenesis and membrane properties.
GO:0036335 intestinal stem cell homeostasis	ISS GO_REF:0000024	KEEP AS NON CORE	Summary: ISS annotation from mouse ortholog. Reason: Pleiotropic downstream effect, not core function. Supporting Evidence: doi:10.1172/jci93616 LPCAT3 modulates membrane composition and signaling.
GO:0045540 regulation of cholesterol biosynthetic process	IEA GO_REF:0000107	KEEP AS NON CORE	Summary: LPCAT3-mediated ER membrane remodeling affects SREBP processing and cholesterol/lipid biosynthesis. Reason: This is an indirect regulatory effect through ER membrane composition affecting SREBP signaling. Not a direct molecular function of LPCAT3. Supporting Evidence: doi:10.1172/jci93616 LPCAT3 promotes processing of sterol regulatory protein SREBF1 in hepatocytes, likely by facilitating the translocation of SREBF1-SCAP complex from ER to the Golgi apparatus.
GO:0045540 regulation of cholesterol biosynthetic process	ISS GO_REF:0000024	KEEP AS NON CORE	Summary: ISS annotation from mouse ortholog. Reason: Indirect regulatory effect, not core function. Supporting Evidence: doi:10.1172/jci93616 ER phospholipid composition modulates lipogenesis.
GO:0045797 positive regulation of intestinal cholesterol absorption	IEA GO_REF:0000107	KEEP AS NON CORE	Summary: Mouse studies show LPCAT3 in enterocytes affects cholesterol absorption. Reason: Tissue-specific downstream effect in intestine through membrane remodeling affecting passive diffusion of cholesterol. Supporting Evidence: doi:10.3892/ijmm.2024.5356 LPCAT3 regulates the abundance of PCs containing linoleate and arachidonate in enterocyte membranes, enabling passive diffusion of fatty acids and cholesterol across the membrane.
GO:0045797 positive regulation of intestinal cholesterol absorption	ISS GO_REF:0000024	KEEP AS NON CORE	Summary: ISS annotation from mouse ortholog. Reason: Tissue-specific downstream effect, not core function. Supporting Evidence: doi:10.3892/ijmm.2024.5356 LPCAT3 affects enterocyte membrane composition and cholesterol handling.
GO:0050728 negative regulation of inflammatory response	IEA GO_REF:0000107	KEEP AS NON CORE	Summary: LPCAT3 may down-regulate inflammation by limiting arachidonic acid availability for inflammatory eicosanoid synthesis. Reason: This is an indirect effect through PUFA incorporation into phospholipids, potentially limiting free AA for inflammatory mediator synthesis. Evidence primarily from mouse studies. Supporting Evidence: doi:10.3892/ijmm.2024.5356 LPCAT3 participates in mechanisms by which the liver X receptor signaling pathway counteracts lipid-induced ER stress response and inflammation. Down-regulates hepatic inflammation by limiting arachidonic acid availability for synthesis of inflammatory eicosanoids.
GO:0050728 negative regulation of inflammatory response	ISS GO_REF:0000024	KEEP AS NON CORE	Summary: ISS annotation from mouse ortholog. Reason: Indirect effect through AA metabolism, not core function. Supporting Evidence: doi:10.3892/ijmm.2024.5356 LPCAT3 limits arachidonic acid availability for inflammatory eicosanoids.
GO:0090158 endoplasmic reticulum membrane organization	IEA GO_REF:0000107	KEEP AS NON CORE	Summary: LPCAT3-mediated phospholipid remodeling affects ER membrane composition and properties. Reason: While LPCAT3 certainly affects ER membrane composition through its remodeling activity, "membrane organization" as a biological process is an indirect consequence rather than a core function. Supporting Evidence: doi:10.1172/jci93616 ER phospholipid composition modulates membrane properties and lipogenesis.
GO:0090158 endoplasmic reticulum membrane organization	ISS GO_REF:0000024	KEEP AS NON CORE	Summary: ISS annotation from mouse ortholog. Reason: Indirect effect of phospholipid remodeling activity. Supporting Evidence: doi:10.1172/jci93616 LPCAT3 shapes ER PC composition.
GO:1903573 negative regulation of response to endoplasmic reticulum stress	IEA GO_REF:0000107	KEEP AS NON CORE	Summary: Mouse studies suggest LPCAT3 counteracts lipid-induced ER stress. Reason: Indirect effect through ER membrane composition. Lpcat3 deficiency in mice exacerbates NASH partly through ER stress mechanisms. Supporting Evidence: doi:10.1097/hep.0000000000000375 Membrane phospholipid remodeling modulates NASH progression by regulating mitochondrial homeostasis.
GO:1903573 negative regulation of response to endoplasmic reticulum stress	ISS GO_REF:0000024	KEEP AS NON CORE	Summary: ISS annotation from mouse ortholog. Reason: Indirect effect through membrane composition. Supporting Evidence: doi:10.1097/hep.0000000000000375 Lpcat3 loss worsens NASH through mitochondrial and membrane effects.
GO:1905885 positive regulation of triglyceride transport	IEA GO_REF:0000107	KEEP AS NON CORE	Summary: LPCAT3 affects TG transport through effects on lipoprotein assembly. Reason: Indirect effect through lipoprotein biogenesis (chylomicron, VLDL). Supporting Evidence: PMID:22511767 In short, these results indicate that hepatic LPCAT3 modulates VLDL production by regulating LysoPC levels and MTP expression.
GO:1905885 positive regulation of triglyceride transport	ISS GO_REF:0000024	KEEP AS NON CORE	Summary: ISS annotation from mouse ortholog. Reason: Indirect effect through lipoprotein metabolism. Supporting Evidence: PMID:22511767 In short, these results indicate that hepatic LPCAT3 modulates VLDL production by regulating LysoPC levels and MTP expression.

Core Functions

Primary enzymatic activity of LPCAT3. Catalyzes transfer of acyl groups (preferentially PUFAs like arachidonic acid) from acyl-CoA to 1-acyl-lysophosphatidylcholine to form phosphatidylcholine. This is the reacylation step of the Lands cycle.

Molecular Function:

1-acylglycerophosphocholine O-acyltransferase activity

Directly Involved In:

phosphatidylcholine acyl-chain remodeling

Cellular Locations:

endoplasmic reticulum membrane

Broader term capturing LPCAT3's activity on multiple lysophospholipid substrates including LPC, LPE, and LPS.

Molecular Function:

lysophospholipid acyltransferase activity

Cellular Locations:

endoplasmic reticulum membrane

Secondary but important activity - remodeling PE with PUFAs, particularly relevant for ferroptosis where AA-PE/AdA-PE are peroxidation substrates.

Molecular Function:

1-acylglycerophosphoethanolamine O-acyltransferase activity

Directly Involved In:

phosphatidylethanolamine acyl-chain remodeling

Cellular Locations:

endoplasmic reticulum membrane

References

GO_REF:0000024

Manual transfer of experimentally-verified manual GO annotation data to orthologs by curator judgment of sequence similarity

GO_REF:0000033

Annotation inferences using phylogenetic trees

GO_REF:0000041

Gene Ontology annotation based on UniPathway vocabulary mapping

GO_REF:0000043

Gene Ontology annotation based on UniProtKB/Swiss-Prot keyword mapping

GO_REF:0000107

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

GO_REF:0000120

Combined Automated Annotation using Multiple IEA Methods

PMID:18195019

Identification and characterization of a major liver lysophosphatidylcholine acyltransferase.

Identified LPCAT3 as the major hepatic lysophosphatidylcholine acyltransferase. LPCAT3 belongs to the MBOAT family, is ER-localized, and shows substrate preference for unsaturated fatty acids. Knockdown in Huh7 cells virtually eliminates membrane LPCAT activity.

"we report here the identification of a novel LPCAT, which we named LPCAT3. LPCAT3 belongs to the membrane-bound O-acyltransferase (MBOAT) family... In a human hepatoma Huh7 cells, RNA interference-mediated knockdown of LPCAT3 resulted in virtually complete loss of membrane LPCAT activity"

PMID:18772128

Lysophospholipid acyltransferases and arachidonate recycling in human neutrophils.

Characterized substrate specificity of MBOAT5/LPCAT3 using MS-based assays. MBOAT5 prefers LPC and lyso-PS with linoleoyl and arachidonoyl acyl-CoA donors. Activity is thimerosal-sensitive. Implicates MBOAT5 in arachidonate recycling and regulation of free AA for leukotriene synthesis.

"MBOAT5 prefers lysophosphatidylcholine and lyso-PS to incorporate linoleoyl and arachidonoyl chains. MBOAT7 is a lysophosphatidylinositol acyltransferase with remarkable specificity for arachidonoyl-CoA. MBOAT5 and MBOAT7 are particularly susceptible to inhibition by thimerosal."

PMID:18782225

Member of the membrane-bound O-acyltransferase (MBOAT) family encodes a lysophospholipid acyltransferase with broad substrate specificity.

Demonstrated that MBOAT5/LPCAT3 is a lysophospholipid acyltransferase acting on LPC, LPS, and LPE. Knockdown reduced PUFA incorporation into PC, PS, and PE. Overexpression increased LPC, LPS, and LPE acyltransferase activities but not LPIAT or LPAAT activities.

"These results indicate that human MBOAT5 is a lysophospholipid acyltransferase acting preferentially on LPC, LPS and LPE."

PMID:19946888

Defining the membrane proteome of NK cells.

High-throughput membrane proteomics study identifying LPCAT3 as a membrane protein in NK cells.

"Mass spectrometric analysis identified 1843 proteins with high confidence scores."

PMID:22511767

Lysophosphatidylcholine acyltransferase 3 knockdown-mediated liver lysophosphatidylcholine accumulation promotes very low density lipoprotein production by enhancing microsomal triglyceride transfer protein expression.

Demonstrated that LPCAT3 is the major hepatic isoform. Knockdown increases LysoPC, decreases certain PC species, and reduces hepatic triglycerides. Paradoxically, knockdown increases plasma TG and apoB through enhanced VLDL secretion via increased MTP expression.

"we found that LPCAT3 is the major hepatic isoform, and its knockdown significantly reduces hepatic LPCAT activity... these results indicate that hepatic LPCAT3 modulates VLDL production by regulating LysoPC levels and MTP expression"

Reactome:R-HSA-1482533

2-acyl LPC is acylated to PC by LPCAT

Reactome:R-HSA-1482547

1-acyl LPC is acylated to PC by LPCAT

Reactome:R-HSA-1482636

1-acyl LPS is acylated to PS by LPSAT

Reactome:R-HSA-1482646

2-acyl LPE is acylated to PE by LPEAT

Reactome:R-HSA-1482667

1-acyl LPE is acylated to PE by LPEAT

Reactome:R-HSA-1482691

2-acyl LPS is acylated to PS by LPSAT

Reactome:R-HSA-1482788

Acyl chain remodelling of PC

Reactome:R-HSA-1482801

Acyl chain remodelling of PS

Reactome:R-HSA-1482839

Acyl chain remodelling of PE

file:human/LPCAT3/LPCAT3-deep-research-falcon.md

Deep research report on LPCAT3

Suggested Experiments

Experiment: CRISPR knockout studies in human hepatocytes to directly assess LPCAT3 contribution to ferroptosis sensitivity

Hypothesis: LPCAT3 knockout will confer resistance to ferroptosis inducers by reducing PUFA-PE substrate availability for lipid peroxidation.

Experiment: Lipidomics profiling of AA-PE/AdA-PE species in LPCAT3 knockdown cells to quantify the ferroptosis substrate pool

Hypothesis: LPCAT3 knockdown will specifically reduce AA-PE and AdA-PE species that serve as ferroptosis substrates.

Experiment: Structural studies with different lysophospholipid substrates to understand headgroup selectivity

Hypothesis: The substrate binding pocket geometry determines preference for LPC over LPE and LPS substrates.

📚 Additional Documentation

Deep Research Falcon

(LPCAT3-deep-research-falcon.md)

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gene_id: LPCAT3
gene_symbol: LPCAT3
uniprot_accession: Q6P1A2
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ECO:0000269|PubMed:18772128, ECO:0000269|PubMed:18782225}; AltName: Full=1-acylglycerophosphoethanolamine
O-acyltransferase; EC=2.3.1.n7 {ECO:0000269|PubMed:18772128, ECO:0000269|PubMed:18782225};
AltName: Full=1-acylglycerophosphoserine O-acyltransferase; EC=2.3.1.n6 {ECO:0000269|PubMed:18195019,
ECO:0000269|PubMed:18772128, ECO:0000269|PubMed:18782225}; AltName: Full=Lysophosphatidylcholine
acyltransferase; Short=LPCAT; Short=Lyso-PC acyltransferase; AltName: Full=Lysophosphatidylcholine
acyltransferase 3; Short=Lyso-PC acyltransferase 3; AltName: Full=Lysophosphatidylserine
acyltransferase; Short=LPSAT; Short=Lyso-PS acyltransferase; AltName: Full=Membrane-bound
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gene_info: Name=LPCAT3; Synonyms=MBOAT5, OACT5;
organism_full: Homo sapiens (Human).
protein_family: Belongs to the membrane-bound acyltransferase family.
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Question

Gene Research for Functional Annotation

⚠️ CRITICAL: Gene/Protein Identification Context

BEFORE YOU BEGIN RESEARCH: You MUST verify you are researching the CORRECT gene/protein. Gene symbols can be ambiguous, especially for less well-characterized genes from non-model organisms.

Target Gene/Protein Identity (from UniProt):

UniProt Accession: Q6P1A2
Protein Description: RecName: Full=Lysophospholipid acyltransferase 5; Short=LPLAT 5; EC=2.3.1.- {ECO:0000269|PubMed:18195019, ECO:0000269|PubMed:18772128, ECO:0000269|PubMed:18782225}; AltName: Full=1-acylglycerophosphocholine O-acyltransferase; EC=2.3.1.23 {ECO:0000269|PubMed:18195019, ECO:0000269|PubMed:18772128, ECO:0000269|PubMed:18782225}; AltName: Full=1-acylglycerophosphoethanolamine O-acyltransferase; EC=2.3.1.n7 {ECO:0000269|PubMed:18772128, ECO:0000269|PubMed:18782225}; AltName: Full=1-acylglycerophosphoserine O-acyltransferase; EC=2.3.1.n6 {ECO:0000269|PubMed:18195019, ECO:0000269|PubMed:18772128, ECO:0000269|PubMed:18782225}; AltName: Full=Lysophosphatidylcholine acyltransferase; Short=LPCAT; Short=Lyso-PC acyltransferase; AltName: Full=Lysophosphatidylcholine acyltransferase 3; Short=Lyso-PC acyltransferase 3; AltName: Full=Lysophosphatidylserine acyltransferase; Short=LPSAT; Short=Lyso-PS acyltransferase; AltName: Full=Membrane-bound O-acyltransferase domain-containing protein 5; Short=O-acyltransferase domain-containing protein 5;
Gene Information: Name=LPCAT3; Synonyms=MBOAT5, OACT5;
Organism (full): Homo sapiens (Human).
Protein Family: Belongs to the membrane-bound acyltransferase family.
Key Domains: LPLAT_7/PORCN-like. (IPR049941); MBOAT_fam. (IPR004299); MBOAT (PF03062)

MANDATORY VERIFICATION STEPS:

Check if the gene symbol "LPCAT3" matches the protein description above
Verify the organism is correct: Homo sapiens (Human).
Check if protein family/domains align with what you find in literature
If you find literature for a DIFFERENT gene with the same or similar symbol, STOP

If Gene Symbol is Ambiguous or You Cannot Find Relevant Literature:

DO NOT PROCEED WITH RESEARCH ON A DIFFERENT GENE. Instead:
- State clearly: "The gene symbol 'LPCAT3' is ambiguous or literature is limited for this specific protein"
- Explain what you found (e.g., "Found extensive literature on a different gene with the same symbol in a different organism")
- Describe the protein based ONLY on the UniProt information provided above
- Suggest that the protein function can be inferred from domain/family information

Research Target:

Please provide a comprehensive research report on the gene LPCAT3 (gene ID: LPCAT3, UniProt: Q6P1A2) in human.

The research report should be a detailed narrative explaining the function, biological processes, and localization of the gene product. Citations should be given for all claims.

You should prioritize authoritative reviews and primary scientific literature when conducting research. You can supplement
this with annotations you find in gene/protein databases, but these can be outdated or inaccurate.

We are specifically interested in the primary function of the gene - for enzymes, what reaction is catalyzed, and what is the substrate specificity? For transporters, what is the substrate? For structural proteins or adapters, what is the broader structural role? For signaling molecules, what is the role in the pathway.

We are interested in where in or outside the cell the gene product carries out its function.

We are also interested in the signaling or biochemical pathways in which the gene functions. We are less interested in broad pleiotropic effects, except where these elucidate the precise role.

Include evidence where possible. We are interested in both experimental evidence as well as inference from structure, evolution, or bioinformatic analysis. Precise studies should be prioritized over high-throughput, where available.

Output

Question: You are an expert researcher providing comprehensive, well-cited information.

Provide detailed information focusing on:
1. Key concepts and definitions with current understanding
2. Recent developments and latest research (prioritize 2023-2024 sources)
3. Current applications and real-world implementations
4. Expert opinions and analysis from authoritative sources
5. Relevant statistics and data from recent studies

Format as a comprehensive research report with proper citations. Include URLs and publication dates where available.
Always prioritize recent, authoritative sources and provide specific citations for all major claims.

Gene Research for Functional Annotation

⚠️ CRITICAL: Gene/Protein Identification Context

BEFORE YOU BEGIN RESEARCH: You MUST verify you are researching the CORRECT gene/protein. Gene symbols can be ambiguous, especially for less well-characterized genes from non-model organisms.

Target Gene/Protein Identity (from UniProt):

UniProt Accession: Q6P1A2
Protein Description: RecName: Full=Lysophospholipid acyltransferase 5; Short=LPLAT 5; EC=2.3.1.- {ECO:0000269|PubMed:18195019, ECO:0000269|PubMed:18772128, ECO:0000269|PubMed:18782225}; AltName: Full=1-acylglycerophosphocholine O-acyltransferase; EC=2.3.1.23 {ECO:0000269|PubMed:18195019, ECO:0000269|PubMed:18772128, ECO:0000269|PubMed:18782225}; AltName: Full=1-acylglycerophosphoethanolamine O-acyltransferase; EC=2.3.1.n7 {ECO:0000269|PubMed:18772128, ECO:0000269|PubMed:18782225}; AltName: Full=1-acylglycerophosphoserine O-acyltransferase; EC=2.3.1.n6 {ECO:0000269|PubMed:18195019, ECO:0000269|PubMed:18772128, ECO:0000269|PubMed:18782225}; AltName: Full=Lysophosphatidylcholine acyltransferase; Short=LPCAT; Short=Lyso-PC acyltransferase; AltName: Full=Lysophosphatidylcholine acyltransferase 3; Short=Lyso-PC acyltransferase 3; AltName: Full=Lysophosphatidylserine acyltransferase; Short=LPSAT; Short=Lyso-PS acyltransferase; AltName: Full=Membrane-bound O-acyltransferase domain-containing protein 5; Short=O-acyltransferase domain-containing protein 5;
Gene Information: Name=LPCAT3; Synonyms=MBOAT5, OACT5;
Organism (full): Homo sapiens (Human).
Protein Family: Belongs to the membrane-bound acyltransferase family.
Key Domains: LPLAT_7/PORCN-like. (IPR049941); MBOAT_fam. (IPR004299); MBOAT (PF03062)

MANDATORY VERIFICATION STEPS:

Check if the gene symbol "LPCAT3" matches the protein description above
Verify the organism is correct: Homo sapiens (Human).
Check if protein family/domains align with what you find in literature
If you find literature for a DIFFERENT gene with the same or similar symbol, STOP

If Gene Symbol is Ambiguous or You Cannot Find Relevant Literature:

Research Target:

Please provide a comprehensive research report on the gene LPCAT3 (gene ID: LPCAT3, UniProt: Q6P1A2) in human.

The research report should be a detailed narrative explaining the function, biological processes, and localization of the gene product. Citations should be given for all claims.

We are interested in where in or outside the cell the gene product carries out its function.

We are also interested in the signaling or biochemical pathways in which the gene functions. We are less interested in broad pleiotropic effects, except where these elucidate the precise role.

Plan and verification
- Identity verified: human LPCAT3 (gene LPCAT3; aliases MBOAT5/OACT5/LPLAT12; UniProt Q6P1A2) is a membrane-bound O-acyltransferase (MBOAT) lysophospholipid acyltransferase that remodels phospholipids in the Lands cycle. It is ER-localized and preferentially incorporates polyunsaturated acyl chains (e.g., arachidonoyl) into the sn-2 position of lysophospholipids, especially lysophosphatidylcholine (LPC). Structural, biochemical, and physiological data align with MBOAT domain features (conserved catalytic His) and the LPLAT family. No symbol ambiguity was encountered (pierce2023arisingtide pages 8-11, zhang2021thestructuralbasis pages 1-2, wang2024researchprogresschallenges pages 4-5).

1) Key concepts and definitions (current understanding)
- Enzymatic function. LPCAT3 catalyzes acyl-CoA-dependent re-acylation of lysophospholipids, primarily LPC, producing phosphatidylcholine (PC) enriched for polyunsaturated fatty acids (PUFAs). Headgroup scope includes LPC as the primary acceptor with reported activity toward LPE and LPS at lower levels; little or no activity for lysoPI/lysoPG is reported in comparative studies of human LPCATs (review synthesis) (korbecki2024phospholipidacyltransferasescharacterization pages 9-10). The acyl donor is typically PUFA-CoA (e.g., arachidonoyl-CoA 20:4-CoA), consistent with in vivo and structural observations of PUFA selectivity (rong2017erphospholipidcomposition pages 6-8, zhang2021thestructuralbasis pages 1-2).
- Structural family features. LPCAT3 is an ER-integral MBOAT enzyme with a central membrane-embedded reaction chamber. High-resolution structures reveal two substrate entry tunnels—one for LPC and one for acyl-CoA—that meet at a catalytic center featuring a conserved histidine, with a side pocket that accommodates the bent PUFA acyl chain, providing a structural basis for PUFA preference (Nature Communications, 2021-11-22; https://doi.org/10.1038/s41467-021-27244-1) (zhang2021thestructuralbasis pages 1-2). Reviews of MBOATs confirm conserved His/Asn motifs and a multi-pass architecture in LPCAT3 (Frontiers in Physiology, 2023-05-30; https://doi.org/10.3389/fphys.2023.1167873) (pierce2023arisingtide pages 8-11).
- Cellular localization and tissue expression. LPCAT3 is predominantly localized to the endoplasmic reticulum; it is highly expressed in liver and small intestine and present in adipose tissue, skeletal muscle, and macrophages, where it controls the PUFA content of membrane PCs (wang2024researchprogresschallenges pages 4-5, rong2017erphospholipidcomposition pages 6-8). Emerging evidence indicates LPCAT3 can also localize to lipid droplets under specific conditions, influencing droplet fusion dynamics (Nature Communications, 2025; human LPCAT3 localization to LDs in cell models) (korbecki2024phospholipidacyltransferasescharacterization pages 27-29).
- Pathway context. LPCAT3 operates in the Lands cycle, remodeling sn-2 acyl chains of PCs and other phospholipids, thereby tuning membrane biophysical properties and signaling lipid pools. In hepatocytes, LPCAT3-driven ER PUFA-PC influences SREBP-1c activation and lipogenesis; in enterocytes, LPCAT3 supports chylomicron assembly by resynthesizing PC for lipoprotein surfaces (rong2017erphospholipidcomposition pages 6-8, wang2024researchprogresschallenges pages 4-5, korbecki2024phospholipidacyltransferasescharacterization pages 27-29).

2) Recent developments and latest research (2023–2024 priority)
- Structural and mechanistic clarity. The 2021 structural work continues to underpin 2023–2024 reviews, highlighting the T-shaped reaction chamber, conserved catalytic His, and PUFA-accommodating side pocket that mechanistically explains LPCAT3’s arachidonoyl-CoA preference (2023 review; https://doi.org/10.3389/fphys.2023.1167873) (pierce2023arisingtide pages 8-11, zhang2021thestructuralbasis pages 1-2).
- Transcriptional regulation and ER remodeling. A 2024 review synthesizes that LPCAT3 is an LXR target in liver and intestine; its induction increases PUFA-PC, modifies ER membrane properties, and connects sterol/lipid signaling to VLDL production and SREBP-1c lipogenesis (Int J Mol Med, 2024-02; https://doi.org/10.3892/ijmm.2024.5356) (wang2024researchprogresschallenges pages 4-5, wang2024researchprogresschallenges pages 7-9). Complementary mechanistic mouse data show hepatocyte LPCAT3 loss reduces PUFA-PC and blunts feeding/insulin-induced SREBP-1c activation (J Clin Invest, 2017-08-31; https://doi.org/10.1172/jci93616) (rong2017erphospholipidcomposition pages 6-8).
- NASH and mitochondrial homeostasis. A 2024 Hepatology study demonstrated that hepatic Lpcat3 deletion promotes ROS, reduces mtDNA and respiratory complexes, and worsens NASH and fibrosis, with altered inner mitochondrial membrane phospholipid saturation; hepatic overexpression of Lpcat3 ameliorated NASH features (Hepatology, 2024-04; https://doi.org/10.1097/hep.0000000000000375) (tian2024membranephospholipidremodeling pages 7-11).
- Ferroptosis axis and interactors. Reviews in 2023–2024 consolidated the ACSL4–LPCAT3–ALOX15 axis: ACSL4 activates AA/AdA to acyl-CoAs, LPCAT3 installs PUFA into PE/PC (e.g., AA-PE), and ALOX enzymes oxidize these to drive ferroptosis; loss of ACSL4 or LPCAT3 confers ferroptosis resistance (Signal Transduct Target Ther, 2023-09-14; https://doi.org/10.1038/s41392-023-01606-1; Antioxidants, 2024-02-21; https://doi.org/10.3390/antiox13030298) (korbecki2024phospholipidacyltransferasescharacterization pages 27-29). A 2024 Protein & Cell study identified CEPT1 as an ER protein that interacts with LPCAT3, regulates LPCAT3 protein stability, and suppresses ferroptosis, adding a new node regulating LPCAT3-linked lipid death pathways (Protein & Cell, 2024-03; https://doi.org/10.1093/procel/pwae004) (korbecki2024phospholipidacyltransferasescharacterization pages 27-29).
- Intestinal lipid absorption. A 2023 review of dietary TG absorption summarized that intestine-specific Lpcat3 deficiency in mice causes enterocyte lipid accumulation and markedly reduced lipid absorption/chylomicron secretion, supporting LPCAT3’s role in enterocytic PC remodeling for lipoprotein biogenesis (Front Pharmacol, 2023-02-16; https://doi.org/10.3389/fphar.2023.1097835) (korbecki2024phospholipidacyltransferasescharacterization pages 27-29). Human tracer studies show enterocytic PC remodeling from dietary PC involves lyso-PC re-acylation consistent with LPCAT3 activity before chylomicron export (Eur J Nutr, 2023-02; https://doi.org/10.1007/s00394-023-03121-z) (korbecki2024phospholipidacyltransferasescharacterization pages 27-29).

3) Current applications and real-world implementations
- Targeting metabolic liver disease. The 2024 NASH study suggests that restoring LPCAT3 levels/activity may improve mitochondrial homeostasis and reduce inflammation/fibrosis, positioning LPCAT3 modulation as a potential therapeutic strategy under investigation (Hepatology, 2024-04; https://doi.org/10.1097/hep.0000000000000375) (tian2024membranephospholipidremodeling pages 7-11). Reviews also propose modulating LXR–LPCAT3 to adjust ER phospholipid composition and lipogenesis in NAFLD (Int J Mol Med, 2024-02; https://doi.org/10.3892/ijmm.2024.5356) (wang2024researchprogresschallenges pages 4-5, wang2024researchprogresschallenges pages 7-9).
- Ferroptosis modulation. Because LPCAT3 contributes to PUFA-PL pools required for ferroptosis, selective inhibition of LPCAT3 or upstream ACSL4 is being explored preclinically to suppress ferroptosis in disease, while enhancing this axis is being studied to sensitize cancer cells; protein interactions (CEPT1) offer additional leverage points (Signal Transduct Target Ther, 2023-09-14; https://doi.org/10.1038/s41392-023-01606-1; Protein & Cell, 2024-03; https://doi.org/10.1093/procel/pwae004) (korbecki2024phospholipidacyltransferasescharacterization pages 27-29).
- Cardiometabolic lipid handling. In liver, modulating LPCAT3 affects VLDL production via ER PC composition and SREBP activation; in intestine, LPCAT3 influences chylomicron output and dietary fat absorption. These principles are informing strategies to manage plasma TG/VLDL and intestinal lipid malabsorption syndromes (J Clin Invest, 2017-08-31; https://doi.org/10.1172/jci93616; Front Pharmacol, 2023-02-16; https://doi.org/10.3389/fphar.2023.1097835) (rong2017erphospholipidcomposition pages 6-8, korbecki2024phospholipidacyltransferasescharacterization pages 27-29).

4) Expert opinions and analysis from authoritative sources
- Structural biology consensus. The Nature Communications 2021 structure provides a unifying mechanistic framework for LPCAT3’s PUFA selectivity and catalytic chemistry (https://doi.org/10.1038/s41467-021-27244-1) (zhang2021thestructuralbasis pages 1-2). The 2023 MBOAT-focused review integrates LPCAT3 into the broader MBOAT mechanistic canon, emphasizing the conserved His/Asn catalytic architecture and substrate tunnels (https://doi.org/10.3389/fphys.2023.1167873) (pierce2023arisingtide pages 8-11).
- Metabolic physiology perspective. JCI 2017 and the 2024 IJMM review by multiple groups place LPCAT3 as a determinant of ER membrane composition that tunes SREBP-1c signaling and VLDL secretion, aligning lipid remodeling with nutrient/hormone responses (https://doi.org/10.1172/jci93616; https://doi.org/10.3892/ijmm.2024.5356) (rong2017erphospholipidcomposition pages 6-8, wang2024researchprogresschallenges pages 4-5, wang2024researchprogresschallenges pages 7-9).
- Disease pathogenesis viewpoint. Hepatology 2024 highlights how membrane PUFA-PC deficits from Lpcat3 loss impair mitochondrial integrity and exacerbate NASH, providing a causal link from phospholipid remodeling to organelle dysfunction and inflammation (https://doi.org/10.1097/hep.0000000000000375) (tian2024membranephospholipidremodeling pages 7-11).

5) Relevant statistics and data from recent studies
- Structural binding/catalysis. Substrate-bound LPCAT3 structures directly visualize arachidonoyl-CoA engaging a side pocket and aligning to the catalytic His; the geometry supports specificity for kinked PUFA chains (Nature Communications, 2021-11-22) (zhang2021thestructuralbasis pages 1-2).
- Hepatic ER lipidomics and SREBP-1c control. In mouse liver, hepatocyte Lpcat3 deletion reduces multiple PUFA-PC species; feeding- and insulin-induced SREBP-1c maturation and Fasn induction are significantly blunted (n≈6 per group; multiple independent experiments) (J Clin Invest, 2017-08-31) (rong2017erphospholipidcomposition pages 6-8).
- NASH progression metrics. Liver-specific Lpcat3 knockout shows: increased lipid peroxidation markers; decreased mtDNA content; reduced respiratory complexes I, II, IV; increased JNK signaling; worsened histologic inflammation/fibrosis; rescue by Lpcat3 overexpression (Hepatology, 2024-04) (tian2024membranephospholipidremodeling pages 7-11).
- Intestinal absorption/chylomicron assembly. Enterocyte Lpcat3 deficiency yields intestinal lipid accumulation and markedly reduced lipid absorption and chylomicron secretion in mice (Front Pharmacol, 2023-02-16) (korbecki2024phospholipidacyltransferasescharacterization pages 27-29). Human deuterated-PC tracer studies demonstrate lyso-PC re-acylation consistent with enterocytic LPCAT3 during chylomicron PC assembly (Eur J Nutr, 2023-02) (korbecki2024phospholipidacyltransferasescharacterization pages 27-29).
- Ferroptosis sensitivity. Reviews synthesize that ACSL4/LPCAT3-dependent AA-PE generation is necessary for ALOX-mediated lipid peroxidation; loss of ACSL4 or LPCAT3 confers resistance in multiple systems, while ER protein CEPT1 interacts with LPCAT3 and modulates stability and ferroptosis responses (2023–2024) (korbecki2024phospholipidacyltransferasescharacterization pages 27-29).

Mechanistic detail: enzyme specificity and catalytic chemistry
- Substrate headgroup specificity. Human LPCAT3 shows the highest activity with LPC; several biochemical studies and reviews report lower but present activity with LPE/LPS, and negligible activity with lysoPI/lysoPG. In vivo functional emphasis remains on PC remodeling (korbecki2024phospholipidacyltransferasescharacterization pages 9-10).
- Acyl donor preference. Structural capture of arachidonoyl-CoA in the LPCAT3 catalytic chamber, together with liver ER lipidomics, supports a functional preference for PUFA acyl-CoAs (18:2, 20:4), enriching sn-2 PUFA in membrane PCs (zhang2021thestructuralbasis pages 1-2, rong2017erphospholipidcomposition pages 6-8, wang2024researchprogresschallenges pages 4-5).
- Catalytic residues and tunnels. The conserved catalytic histidine sits where the acyl donor and acceptor tunnels meet; a side pocket accommodates the unsaturated chain bend of arachidonate, rationalizing PUFA selectivity (zhang2021thestructuralbasis pages 1-2, pierce2023arisingtide pages 8-11).

Localization and regulation
- ER and LD association. LPCAT3 is ER-resident; experimental data show co-localization at ER and, in model systems, recruitment to lipid droplets where it can influence droplet fusion and size, suggesting context-dependent localization (korbecki2024phospholipidacyltransferasescharacterization pages 27-29, wang2024researchprogresschallenges pages 4-5).
- Transcriptional control. LPCAT3 is directly induced by liver X receptor (LXR) signaling and integrates with SREBP-1c lipogenesis; hepatic Lpcat3 expression is increased in obesity and feeding states and decreased when SCAP/SREBP is suppressed (rong2017erphospholipidcomposition pages 6-8, wang2024researchprogresschallenges pages 4-5, wang2024researchprogresschallenges pages 7-9).

Physiology and disease links
- Intestine. LPCAT3 drives enterocytic PC remodeling necessary for chylomicron assembly; deficiency reduces dietary lipid absorption and plasma lipids due to impaired chylomicron secretion (korbecki2024phospholipidacyltransferasescharacterization pages 27-29).
- Liver. LPCAT3 shapes ER PC composition controlling SREBP-1c and VLDL secretion; deficiency reduces PUFA-PC, blunts lipogenic signaling, and worsens NASH via mitochondrial impairment (rong2017erphospholipidcomposition pages 6-8, tian2024membranephospholipidremodeling pages 7-11).
- Ferroptosis. The ACSL4–LPCAT3–ALOX15 module generates PUFA-PE/PC substrates for peroxidation; genetic or pharmacologic attenuation of ACSL4/LPCAT3 reduces susceptibility, while CEPT1–LPCAT3 interaction adds regulatory complexity (korbecki2024phospholipidacyltransferasescharacterization pages 27-29).

Limitations and open questions
- Human clinical genetics and trials directly targeting LPCAT3 are still limited; most detailed mechanistic data derive from mouse models, structural biology, and cell systems. Nonetheless, human-relevant enterocyte remodeling and disease correlations are accumulating (korbecki2024phospholipidacyltransferasescharacterization pages 27-29, tian2024membranephospholipidremodeling pages 7-11, wang2024researchprogresschallenges pages 4-5).

Key recent sources summary
| Year | Study (first author, journal) | Focus / Claim | Key evidence / stat (citation) | URL |
|---|---|---|---|---|
| 2021 | Zhang et al., Nature Communications | LPCAT3 structure and catalytic mechanism; arachidonoyl-CoA donor; T-shaped reaction chamber | Cryo-EM / X-ray structures (apo, donor- and acceptor-bound); central cavity and conserved catalytic His aligning with arachidonoyl-CoA (structural basis for PUFA preference) (zhang2021thestructuralbasis pages 1-2) | https://doi.org/10.1038/s41467-021-27244-1 |
| 2023 | Pierce & Hougland, Frontiers in Physiology | MBOAT family overview; conserved MBOAT motifs and catalytic His/Asn residues | Comparative MBOAT structural review noting LPCAT3 has 11 TM helices, conserved His/Asn catalytic residues and side pocket accommodating PUFA chains (pierce2023arisingtide pages 8-11) | https://doi.org/10.3389/fphys.2023.1167873 |
| 2017 | Rong et al., Journal of Clinical Investigation | ER phospholipid remodeling by LPCAT3 regulates SREBP-1c–dependent lipogenesis | Hepatocyte-specific Lpcat3 KO blunted feeding-induced SREBP-1c maturation and Fasn induction; ER lipidomics showed loss of many PUFA-PC species (n≈6/group in refed studies) (rong2017erphospholipidcomposition pages 6-8) | https://doi.org/10.1172/jci93616 |
| 2024 | Wang et al., Int J Mol Med (review) | LXR→LPCAT3 regulatory axis; LPCAT3 role in NAFLD and tissue expression | Review: LPCAT3 is ER-localized, highly expressed in liver/intestine/adipose, accounts for >90% hepatic LPC acyltransferase activity; LXR agonists induce LPCAT3 and PUFA-PC levels, linking to VLDL/TG handling (wang2024researchprogresschallenges pages 4-5) | https://doi.org/10.3892/ijmm.2024.5356 |
| 2024 | Tian et al., Hepatology | Lpcat3 deficiency exacerbates NASH via mitochondrial dysfunction | Liver-specific Lpcat3 KO: ↑lipid peroxidation, ↓mtDNA, reduced respiratory complexes I/II/IV, altered inner mitochondrial membrane PL saturation; worsened inflammation/fibrosis in diet models (tian2024membranephospholipidremodeling pages 7-11) | https://doi.org/10.1097/hep.0000000000000375 |
| 2024 | Liu et al., Protein & Cell | CEPT1 interacts with LPCAT3 and modulates ferroptosis | Proteomics and co-localization: CEPT1 binds LPCAT3 at ER, regulates LPCAT3 protein stability; CEPT1 activity suppresses ferroptosis possibly via breaking pro-ferroptotic PUFA-PLs (korbecki2024phospholipidacyltransferasescharacterization pages 27-29) | https://doi.org/10.1093/procel/pwae004 |
| 2023 | Sun et al., Signal Transduct Target Ther. / Punziano et al., Antioxidants (reviews) | ACSL4–LPCAT3–ALOX15 axis generates PUFA‑PL substrates for ferroptosis | Reviews summary: ACSL4 activates AA/AdA→acyl‑CoA; LPCAT3 esterifies PUFA‑CoAs into PUFA‑PE/PC (e.g., AA‑PE) that ALOX enzymes oxidize to drive ferroptosis; loss of ACSL4 or LPCAT3 reduces ferroptosis sensitivity (korbecki2024phospholipidacyltransferasescharacterization pages 27-29) | https://doi.org/10.1038/s41392-023-01606-1 , https://doi.org/10.3390/antiox13030298 |
| 2023 | Li et al., Frontiers in Pharmacology | Intestine-specific Lpcat3 deficiency impairs dietary lipid absorption and chylomicron assembly | Intestine-specific Lpcat3 KO mice: enterocyte lipid accumulation and markedly reduced lipid absorption / chylomicron secretion, implicating LPCAT3 in enterocyte PC remodeling for lipoprotein biogenesis (korbecki2024phospholipidacyltransferasescharacterization pages 27-29) | https://doi.org/10.3389/fphar.2023.1097835 |
| 2023 | Böckmann et al., European Journal of Nutrition | Dietary phosphatidylcholine remodeling in enterocytes involves LPCAT3 | Deuterated-PC feeding in humans shows enterocytic remodeling of PC (cleavage to lyso‑PC and re-acylation), implicating enterocytic LPCAT3 in producing PC species for chylomicron assembly (korbecki2024phospholipidacyltransferasescharacterization pages 27-29) | https://doi.org/10.1007/s00394-023-03121-z |

Table: Compact summary table of key (2021–2024) primary and review sources on human LPCAT3 covering structure, enzymology, regulation, roles in lipid handling and ferroptosis; citations link to the context IDs used.

References (with URLs and dates)
- Zhang Q et al. The structural basis for the phospholipid remodeling by LPCAT3. Nature Communications. 2021-11-22. https://doi.org/10.1038/s41467-021-27244-1 (zhang2021thestructuralbasis pages 1-2)
- Pierce MR, Hougland JL. A rising tide lifts all MBOATs. Frontiers in Physiology. 2023-05-30. https://doi.org/10.3389/fphys.2023.1167873 (pierce2023arisingtide pages 8-11)
- Rong X et al. ER phospholipid composition modulates lipogenesis. J Clin Invest. 2017-08-31. https://doi.org/10.1172/jci93616 (rong2017erphospholipidcomposition pages 6-8)
- Wang J et al. LXR–LPCAT3 pathway and NAFLD. Int J Mol Med. 2024-02. https://doi.org/10.3892/ijmm.2024.5356 (wang2024researchprogresschallenges pages 4-5, wang2024researchprogresschallenges pages 7-9)
- Tian Y et al. Membrane phospholipid remodeling modulates NASH. Hepatology. 2024-04. https://doi.org/10.1097/hep.0000000000000375 (tian2024membranephospholipidremodeling pages 7-11)
- Liu X et al. CEPT1 interacts with LPCAT3 to suppress ferroptosis. Protein & Cell. 2024-03. https://doi.org/10.1093/procel/pwae004 (korbecki2024phospholipidacyltransferasescharacterization pages 27-29)
- Sun S et al. Targeting ferroptosis for therapeutics. Signal Transduct Target Ther. 2023-09-14. https://doi.org/10.1038/s41392-023-01606-1 (korbecki2024phospholipidacyltransferasescharacterization pages 27-29)
- Punziano C et al. Antioxidant systems modulate ferroptosis. Antioxidants. 2024-02-21. https://doi.org/10.3390/antiox13030298 (korbecki2024phospholipidacyltransferasescharacterization pages 27-29)
- Li X et al. Dietary TG absorption in obesity. Front Pharmacol. 2023-02-16. https://doi.org/10.3389/fphar.2023.1097835 (korbecki2024phospholipidacyltransferasescharacterization pages 27-29)
- Böckmann KA et al. Choline supplement metabolism; enterocyte PC remodeling. Eur J Nutr. 2023-02. https://doi.org/10.1007/s00394-023-03121-z (korbecki2024phospholipidacyltransferasescharacterization pages 27-29)
- Korbecki J et al. Phospholipid acyltransferases in disease (overview of LPCAT3 scope). Cancers. 2024-05. https://doi.org/10.3390/cancers16112115 (korbecki2024phospholipidacyltransferasescharacterization pages 9-10, korbecki2024phospholipidacyltransferasescharacterization pages 27-29)

References

(pierce2023arisingtide pages 8-11): Mariah R. Pierce and James L. Hougland. A rising tide lifts all mboats: recent progress in structural and functional understanding of membrane bound o-acyltransferases. Frontiers in Physiology, May 2023. URL: https://doi.org/10.3389/fphys.2023.1167873, doi:10.3389/fphys.2023.1167873. This article has 20 citations and is from a poor quality or predatory journal.
(zhang2021thestructuralbasis pages 1-2): Qing Zhang, Deqiang Yao, Bing Rao, Liyan Jian, Yang Chen, Kexin Hu, Ying Xia, Shaobai Li, Yafeng Shen, An Qin, Jie Zhao, Lu Zhou, Ming Lei, Xian-Cheng Jiang, and Yu Cao. The structural basis for the phospholipid remodeling by lysophosphatidylcholine acyltransferase 3. Nature Communications, Nov 2021. URL: https://doi.org/10.1038/s41467-021-27244-1, doi:10.1038/s41467-021-27244-1. This article has 90 citations and is from a highest quality peer-reviewed journal.
(wang2024researchprogresschallenges pages 4-5): Junmin Wang, Jiacheng Li, Yu-Hang Fu, Yingying Zhu, Liubing Lin, and Yong Li. Research progress, challenges and perspectives of phospholipids metabolism in the lxr-lpcat3 signaling pathway and its relation to nafld (review). International Journal of Molecular Medicine, Feb 2024. URL: https://doi.org/10.3892/ijmm.2024.5356, doi:10.3892/ijmm.2024.5356. This article has 11 citations and is from a peer-reviewed journal.
(korbecki2024phospholipidacyltransferasescharacterization pages 9-10): Jan Korbecki, Mateusz Bosiacki, Maciej Pilarczyk, Magdalena Gąssowska-Dobrowolska, Paweł Jarmużek, Izabela Szućko-Kociuba, Justyna Kulik-Sajewicz, Dariusz Chlubek, and Irena Baranowska-Bosiacka. Phospholipid acyltransferases: characterization and involvement of the enzymes in metabolic and cancer diseases. Cancers, 16:2115, May 2024. URL: https://doi.org/10.3390/cancers16112115, doi:10.3390/cancers16112115. This article has 7 citations and is from a poor quality or predatory journal.
(rong2017erphospholipidcomposition pages 6-8): Xin Rong, Bo Wang, Elisa N.D. Palladino, Thomas Q. de Aguiar Vallim, David A. Ford, and Peter Tontonoz. Er phospholipid composition modulates lipogenesis during feeding and in obesity. The Journal of clinical investigation, 127 10:3640-3651, Aug 2017. URL: https://doi.org/10.1172/jci93616, doi:10.1172/jci93616. This article has 95 citations.
(korbecki2024phospholipidacyltransferasescharacterization pages 27-29): Jan Korbecki, Mateusz Bosiacki, Maciej Pilarczyk, Magdalena Gąssowska-Dobrowolska, Paweł Jarmużek, Izabela Szućko-Kociuba, Justyna Kulik-Sajewicz, Dariusz Chlubek, and Irena Baranowska-Bosiacka. Phospholipid acyltransferases: characterization and involvement of the enzymes in metabolic and cancer diseases. Cancers, 16:2115, May 2024. URL: https://doi.org/10.3390/cancers16112115, doi:10.3390/cancers16112115. This article has 7 citations and is from a poor quality or predatory journal.
(wang2024researchprogresschallenges pages 7-9): Junmin Wang, Jiacheng Li, Yu-Hang Fu, Yingying Zhu, Liubing Lin, and Yong Li. Research progress, challenges and perspectives of phospholipids metabolism in the lxr-lpcat3 signaling pathway and its relation to nafld (review). International Journal of Molecular Medicine, Feb 2024. URL: https://doi.org/10.3892/ijmm.2024.5356, doi:10.3892/ijmm.2024.5356. This article has 11 citations and is from a peer-reviewed journal.
(tian2024membranephospholipidremodeling pages 7-11): Ye Tian, Matthew J. Jellinek, Kritika Mehta, Sun Mi Seok, Shanny H. Kuo, Wei Lu, Ruicheng Shi, Richard Lee, Gee W. Lau, Jongsook Kim Kemper, Kai Zhang, David A. Ford, and Bo Wang. Membrane phospholipid remodeling modulates nonalcoholic steatohepatitis progression by regulating mitochondrial homeostasis. Hepatology, 79:882-897, Apr 2024. URL: https://doi.org/10.1097/hep.0000000000000375, doi:10.1097/hep.0000000000000375. This article has 33 citations and is from a highest quality peer-reviewed journal.

Citations

korbecki2024phospholipidacyltransferasescharacterization pages 9-10
zhang2021thestructuralbasis pages 1-2
pierce2023arisingtide pages 8-11
korbecki2024phospholipidacyltransferasescharacterization pages 27-29
rong2017erphospholipidcomposition pages 6-8
tian2024membranephospholipidremodeling pages 7-11
wang2024researchprogresschallenges pages 4-5
wang2024researchprogresschallenges pages 7-9
https://doi.org/10.1038/s41467-021-27244-1
https://doi.org/10.3389/fphys.2023.1167873
https://doi.org/10.3892/ijmm.2024.5356
https://doi.org/10.1172/jci93616
https://doi.org/10.1097/hep.0000000000000375
https://doi.org/10.1038/s41392-023-01606-1;
https://doi.org/10.3390/antiox13030298
https://doi.org/10.1093/procel/pwae004
https://doi.org/10.3389/fphar.2023.1097835
https://doi.org/10.1007/s00394-023-03121-z
https://doi.org/10.1172/jci93616;
https://doi.org/10.1038/s41392-023-01606-1
https://doi.org/10.3390/cancers16112115
https://doi.org/10.3389/fphys.2023.1167873,
https://doi.org/10.1038/s41467-021-27244-1,
https://doi.org/10.3892/ijmm.2024.5356,
https://doi.org/10.3390/cancers16112115,
https://doi.org/10.1172/jci93616,
https://doi.org/10.1097/hep.0000000000000375,

📄 View Raw YAML

id: Q6P1A2
gene_symbol: LPCAT3
product_type: PROTEIN
status: COMPLETE
taxon:
  id: NCBITaxon:9606
  label: Homo sapiens
description: Lysophospholipid acyltransferase 5 (LPCAT3/MBOAT5) is an 
  ER-localized membrane-bound O-acyltransferase that catalyzes the reacylation 
  step of the Lands cycle, preferentially incorporating polyunsaturated fatty 
  acids (especially arachidonic acid) into the sn-2 position of 
  lysophospholipids. LPCAT3 shows broad substrate specificity, acting on 
  lysophosphatidylcholine (LPC), lysophosphatidylethanolamine (LPE), and 
  lysophosphatidylserine (LPS), with highest activity toward LPC. The enzyme is 
  highly expressed in liver, intestine, and adipose tissue. LPCAT3 plays 
  critical roles in phospholipid remodeling for membrane composition, VLDL and 
  chylomicron assembly, SREBP-1c signaling regulation, and contributes to the 
  ferroptosis pathway through generation of PUFA-containing phospholipids that 
  serve as substrates for lipid peroxidation.
existing_annotations:
  - term:
      id: GO:0047184
      label: 1-acylglycerophosphocholine O-acyltransferase activity
    evidence_type: IBA
    original_reference_id: GO_REF:0000033
    review:
      summary: This is the core enzymatic activity of LPCAT3 (LPCAT = 
        lysophosphatidylcholine acyltransferase). LPCAT3 catalyzes the transfer 
        of acyl groups from acyl-CoA to 1-acyl-lysophosphatidylcholine to form 
        phosphatidylcholine. This activity has been demonstrated directly in 
        multiple biochemical studies (PMID:18195019, PMID:18772128, 
        PMID:18782225).
      action: ACCEPT
      reason: This is the primary named enzymatic activity of LPCAT3. Multiple 
        independent studies have demonstrated this activity experimentally. Zhao
        et al. 2008 showed that "Membranes from HEK293 cells overexpressing 
        LPCAT3 showed significantly increased LPCAT activity" (PMID:18195019). 
        Gijon et al. 2008 confirmed "MBOAT5 prefers lysophosphatidylcholine and 
        lyso-PS to incorporate linoleoyl and arachidonoyl chains" 
        (PMID:18772128). The IBA annotation is phylogenetically supported and 
        consistent with all biochemical evidence.
      supported_by:
        - reference_id: PMID:18195019
          supporting_text: Membranes from HEK293 cells overexpressing LPCAT3 
            showed significantly increased LPCAT activity as assessed by thin 
            layer chromatography analysis with substrate preference toward 
            unsaturated fatty acids.
        - reference_id: PMID:18772128
          supporting_text: MBOAT5 prefers lysophosphatidylcholine and lyso-PS to
            incorporate linoleoyl and arachidonoyl chains.
        - reference_id: file:human/LPCAT3/LPCAT3-deep-research-falcon.md
          supporting_text: 'model: Edison Scientific Literature'
  - term:
      id: GO:0047184
      label: 1-acylglycerophosphocholine O-acyltransferase activity
    evidence_type: IEA
    original_reference_id: GO_REF:0000120
    review:
      summary: IEA annotation for the core LPCAT activity based on UniProt 
        mapping and RHEA reaction cross-references. This duplicates the IBA 
        annotation but from a computational source.
      action: ACCEPT
      reason: This is the core enzymatic function of LPCAT3, well-supported by 
        experimental evidence from multiple sources. The IEA mapping is 
        consistent with experimental data.
      supported_by:
        - reference_id: PMID:18195019
          supporting_text: LPCAT3 belongs to the membrane-bound 
            O-acyltransferase (MBOAT) family and encodes a protein of 487 amino 
            acids... LPCAT3 is primarily responsible for hepatic LPCAT activity.
  - term:
      id: GO:0047184
      label: 1-acylglycerophosphocholine O-acyltransferase activity
    evidence_type: IDA
    original_reference_id: PMID:18782225
    review:
      summary: Direct biochemical demonstration of LPCAT activity by Matsuda et 
        al. 2008. Over-expression of MBOAT5 in HEK293 cells resulted in great 
        increases in LPC acyltransferase activity using arachidonoyl-CoA as 
        donor.
      action: ACCEPT
      reason: Direct experimental evidence from reconstitution studies in HEK293
        cells showing LPCAT activity is strongly increased upon MBOAT5/LPCAT3 
        overexpression.
      supported_by:
        - reference_id: PMID:18782225
          supporting_text: Conversely, over-expression of MBOAT5 in human 
            embryonic kidney (HEK) 293 cells resulted in great increases in LPC,
            LPS and LPE acyltransferase activities but not in LPIAT or 
            lysophosphatidic acid (LPA) acyltransferase (LPAAT) activities.
  - term:
      id: GO:0047184
      label: 1-acylglycerophosphocholine O-acyltransferase activity
    evidence_type: IDA
    original_reference_id: PMID:18195019
    review:
      summary: Zhao et al. 2008 identified LPCAT3 as the major liver LPCAT and 
        characterized its enzymatic activity with various acyl-CoA substrates, 
        showing preference for unsaturated fatty acids.
      action: ACCEPT
      reason: Key primary study identifying LPCAT3 and demonstrating its 
        enzymatic activity directly. Shows LPCAT3 is the major hepatic LPCAT 
        enzyme.
      supported_by:
        - reference_id: PMID:18195019
          supporting_text: In a human hepatoma Huh7 cells, RNA 
            interference-mediated knockdown of LPCAT3 resulted in virtually 
            complete loss of membrane LPCAT activity, suggesting that LPCAT3 is 
            primarily responsible for hepatic LPCAT activity.
  - term:
      id: GO:0047184
      label: 1-acylglycerophosphocholine O-acyltransferase activity
    evidence_type: IDA
    original_reference_id: PMID:18772128
    review:
      summary: Gijon et al. 2008 used mass spectrometry-based enzyme assays to 
        characterize MBOAT5/LPCAT3 substrate specificity, showing preference for
        LPC with linoleoyl and arachidonoyl donors.
      action: ACCEPT
      reason: High-quality biochemical characterization using novel MS-based 
        assays confirming LPC acyltransferase activity with PUFA preference.
      supported_by:
        - reference_id: PMID:18772128
          supporting_text: MBOAT5 prefers lysophosphatidylcholine and lyso-PS to
            incorporate linoleoyl and arachidonoyl chains.
  - term:
      id: GO:0047184
      label: 1-acylglycerophosphocholine O-acyltransferase activity
    evidence_type: IMP
    original_reference_id: PMID:22511767
    review:
      summary: Li et al. 2012 showed that LPCAT3 knockdown significantly reduces
        hepatic LPCAT activity, providing mutant phenotype evidence for this 
        molecular function.
      action: ACCEPT
      reason: Important study confirming LPCAT3 as the major hepatic LPCAT 
        isoform through knockdown experiments showing loss of enzymatic 
        activity.
      supported_by:
        - reference_id: PMID:22511767
          supporting_text: We found that LPCAT3 is the major hepatic isoform, 
            and its knockdown significantly reduces hepatic LPCAT activity.
  - term:
      id: GO:0071617
      label: lysophospholipid acyltransferase activity
    evidence_type: IBA
    original_reference_id: GO_REF:0000033
    review:
      summary: LPCAT3 is indeed a lysophospholipid acyltransferase with broad 
        substrate specificity encompassing LPC, LPE, and LPS. This broader term 
        correctly captures the enzyme's range of substrates.
      action: ACCEPT
      reason: Appropriate parent term that accurately reflects the enzyme's 
        activity on multiple lysophospholipid substrates. Matsuda et al. 2008 
        demonstrated that MBOAT5 "is a lysophospholipid acyltransferase acting 
        preferentially on LPC, LPS and LPE" (PMID:18782225).
      supported_by:
        - reference_id: PMID:18782225
          supporting_text: These results indicate that human MBOAT5 is a 
            lysophospholipid acyltransferase acting preferentially on LPC, LPS 
            and LPE.
  - term:
      id: GO:0106262
      label: 1-acylglycerophosphoethanolamine O-acyltransferase activity
    evidence_type: IEA
    original_reference_id: GO_REF:0000120
    review:
      summary: LPCAT3 has documented LPEAT activity, transferring acyl groups to
        lysophosphatidylethanolamine. This is a secondary but well-characterized
        activity.
      action: ACCEPT
      reason: LPEAT activity has been experimentally demonstrated, though it is 
        lower than LPCAT activity. UniProt assigns EC 2.3.1.n7 for this activity
        based on PMID:18772128 and PMID:18782225.
      supported_by:
        - reference_id: PMID:18772128
          supporting_text: Human neutrophils express mRNA for these four 
            enzymes, and neutrophil microsomes incorporate arachidonoyl chains 
            into phosphatidylinositol, phosphatidylcholine, PS, and 
            phosphatidylethanolamine in a thimerosal-sensitive manner.
  - term:
      id: GO:0106262
      label: 1-acylglycerophosphoethanolamine O-acyltransferase activity
    evidence_type: ISS
    original_reference_id: GO_REF:0000024
    review:
      summary: ISS annotation for LPEAT activity based on mouse ortholog data.
      action: ACCEPT
      reason: Sequence similarity annotation is consistent with direct 
        experimental evidence for this activity in human LPCAT3.
      supported_by:
        - reference_id: PMID:18782225
          supporting_text: Conversely, over-expression of MBOAT5 in human 
            embryonic kidney (HEK) 293 cells resulted in great increases in LPC,
            LPS and LPE acyltransferase activities but not in LPIAT or 
            lysophosphatidic acid (LPA) acyltransferase (LPAAT) activities.
  - term:
      id: GO:0106262
      label: 1-acylglycerophosphoethanolamine O-acyltransferase activity
    evidence_type: IDA
    original_reference_id: PMID:18772128
    review:
      summary: Direct demonstration of LPEAT activity by Gijon et al. 2008 using
        MS-based enzyme assays.
      action: ACCEPT
      reason: Direct experimental evidence showing MBOAT5/LPCAT3 can acylate 
        LPE, though this is a secondary activity compared to LPC.
      supported_by:
        - reference_id: PMID:18772128
          supporting_text: Human neutrophils express mRNA for these four 
            enzymes, and neutrophil microsomes incorporate arachidonoyl chains 
            into phosphatidylinositol, phosphatidylcholine, PS, and 
            phosphatidylethanolamine in a thimerosal-sensitive manner.
  - term:
      id: GO:0106262
      label: 1-acylglycerophosphoethanolamine O-acyltransferase activity
    evidence_type: IDA
    original_reference_id: PMID:18782225
    review:
      summary: Matsuda et al. 2008 demonstrated LPE acyltransferase activity 
        through overexpression studies in HEK293 cells.
      action: ACCEPT
      reason: Direct experimental evidence confirming LPEAT activity of 
        MBOAT5/LPCAT3.
      supported_by:
        - reference_id: PMID:18782225
          supporting_text: Conversely, over-expression of MBOAT5 in human 
            embryonic kidney (HEK) 293 cells resulted in great increases in LPC,
            LPS and LPE acyltransferase activities but not in LPIAT or 
            lysophosphatidic acid (LPA) acyltransferase (LPAAT) activities.
  - term:
      id: GO:0106263
      label: 1-acylglycerophosphoserine O-acyltransferase activity
    evidence_type: IEA
    original_reference_id: GO_REF:0000120
    review:
      summary: LPCAT3 has documented LPSAT activity, acylating 
        lysophosphatidylserine.
      action: ACCEPT
      reason: LPSAT activity is experimentally supported. UniProt assigns EC 
        2.3.1.n6 based on multiple experimental studies.
      supported_by:
        - reference_id: PMID:18782225
          supporting_text: These results indicate that human MBOAT5 is a 
            lysophospholipid acyltransferase acting preferentially on LPC, LPS 
            and LPE.
  - term:
      id: GO:0106263
      label: 1-acylglycerophosphoserine O-acyltransferase activity
    evidence_type: IDA
    original_reference_id: PMID:18195019
    review:
      summary: Zhao et al. 2008 demonstrated LPSAT activity in their 
        characterization of LPCAT3.
      action: ACCEPT
      reason: Direct experimental evidence for LPS acyltransferase activity.
      supported_by:
        - reference_id: PMID:18782225
          supporting_text: These results indicate that human MBOAT5 is a 
            lysophospholipid acyltransferase acting preferentially on LPC, LPS 
            and LPE.
  - term:
      id: GO:0106263
      label: 1-acylglycerophosphoserine O-acyltransferase activity
    evidence_type: IDA
    original_reference_id: PMID:18772128
    review:
      summary: Gijon et al. 2008 confirmed LPS acyltransferase activity using 
        MS-based assays.
      action: ACCEPT
      reason: High-quality MS-based biochemical evidence for LPSAT activity.
      supported_by:
        - reference_id: PMID:18772128
          supporting_text: MBOAT5 prefers lysophosphatidylcholine and lyso-PS to
            incorporate linoleoyl and arachidonoyl chains.
  - term:
      id: GO:0106263
      label: 1-acylglycerophosphoserine O-acyltransferase activity
    evidence_type: IDA
    original_reference_id: PMID:18782225
    review:
      summary: Matsuda et al. 2008 demonstrated LPS acyltransferase activity 
        through overexpression studies.
      action: ACCEPT
      reason: Direct experimental evidence for LPSAT activity.
      supported_by:
        - reference_id: PMID:18782225
          supporting_text: Conversely, over-expression of MBOAT5 in human 
            embryonic kidney (HEK) 293 cells resulted in great increases in LPC,
            LPS and LPE acyltransferase activities but not in LPIAT or 
            lysophosphatidic acid (LPA) acyltransferase (LPAAT) activities.
  - term:
      id: GO:0003841
      label: 1-acylglycerol-3-phosphate O-acyltransferase activity
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1482547
    review:
      summary: Reactome annotation for AGPAT-like activity. However, LPCAT3 acts
        on lysophospholipids (with headgroups like choline, ethanolamine, 
        serine), not on lysophosphatidic acid (LPA). This activity is distinct 
        from true AGPAT/LPAAT activity.
      action: UNDECIDED
      reason: This term refers to activity on 1-acylglycerol-3-phosphate 
        (lysophosphatidic acid), which is different from the lysophospholipids 
        that LPCAT3 prefers. Matsuda et al. 2008 explicitly showed that MBOAT5 
        overexpression did NOT increase LPAAT activity (PMID:18782225). The 
        Reactome pathway may be capturing a related reaction step in 
        phospholipid remodeling, but the GO term may be imprecise. Need to 
        verify the exact Reactome reaction definition.
      additional_reference_ids:
        - PMID:18782225
      supported_by:
        - reference_id: PMID:18782225
          supporting_text: Conversely, over-expression of MBOAT5 in human 
            embryonic kidney (HEK) 293 cells resulted in great increases in LPC,
            LPS and LPE acyltransferase activities but not in LPIAT or 
            lysophosphatidic acid (LPA) acyltransferase (LPAAT) activities.
  - term:
      id: GO:0003841
      label: 1-acylglycerol-3-phosphate O-acyltransferase activity
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1482636
    review:
      summary: Second Reactome annotation for AGPAT activity.
      action: UNDECIDED
      reason: Same concern as above - LPCAT3 lacks significant LPAAT activity 
        according to direct biochemical studies. The Reactome pathway context 
        needs verification.
      supported_by:
        - reference_id: PMID:18782225
          supporting_text: Conversely, over-expression of MBOAT5 in human 
            embryonic kidney (HEK) 293 cells resulted in great increases in LPC,
            LPS and LPE acyltransferase activities but not in LPIAT or 
            lysophosphatidic acid (LPA) acyltransferase (LPAAT) activities.
  - term:
      id: GO:0003841
      label: 1-acylglycerol-3-phosphate O-acyltransferase activity
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1482667
    review:
      summary: Third Reactome annotation for AGPAT activity.
      action: UNDECIDED
      reason: Same concern - experimental evidence suggests LPCAT3 does not have
        significant LPAAT activity.
      supported_by:
        - reference_id: PMID:18782225
          supporting_text: Conversely, over-expression of MBOAT5 in human 
            embryonic kidney (HEK) 293 cells resulted in great increases in LPC,
            LPS and LPE acyltransferase activities but not in LPIAT or 
            lysophosphatidic acid (LPA) acyltransferase (LPAAT) activities.
  - term:
      id: GO:0047144
      label: 2-acylglycerol-3-phosphate O-acyltransferase activity
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1482533
    review:
      summary: Reactome annotation for acyltransferase activity at the sn-1 
        position of 2-acyl-lysophospholipids.
      action: UNDECIDED
      reason: LPCAT3 primarily acts on 1-acyl-lysophospholipids (re-acylating at
        sn-2 position), not 2-acyl-lysophospholipids. This annotation may 
        reflect a minor activity or may be pathway modeling that requires 
        verification.
      supported_by:
        - reference_id: PMID:18195019
          supporting_text: The reacylation step is catalyzed by 
            lysophosphatidylcholine acyltransferase (LPCAT), and we report here 
            the identification of a novel LPCAT, which we named LPCAT3.
  - term:
      id: GO:0047144
      label: 2-acylglycerol-3-phosphate O-acyltransferase activity
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1482646
    review:
      summary: Second Reactome annotation for 2-AGPAT activity.
      action: UNDECIDED
      reason: Same concern - primary activity is on 1-acyl-lysophospholipids, 
        not 2-acyl.
      supported_by:
        - reference_id: PMID:18195019
          supporting_text: The reacylation step is catalyzed by 
            lysophosphatidylcholine acyltransferase (LPCAT), and we report here 
            the identification of a novel LPCAT, which we named LPCAT3.
  - term:
      id: GO:0047144
      label: 2-acylglycerol-3-phosphate O-acyltransferase activity
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1482691
    review:
      summary: Third Reactome annotation for 2-AGPAT activity.
      action: UNDECIDED
      reason: Same concern regarding substrate specificity.
      supported_by:
        - reference_id: PMID:18195019
          supporting_text: The reacylation step is catalyzed by 
            lysophosphatidylcholine acyltransferase (LPCAT), and we report here 
            the identification of a novel LPCAT, which we named LPCAT3.
  - term:
      id: GO:0016740
      label: transferase activity
    evidence_type: IEA
    original_reference_id: GO_REF:0000043
    review:
      summary: Very general term for transferase activity based on UniProt 
        keyword mapping.
      action: MARK_AS_OVER_ANNOTATED
      reason: This term is too general to be informative. LPCAT3 has specific 
        lysophospholipid acyltransferase activities that are captured by more 
        specific terms (GO:0047184, GO:0071617, GO:0106262, GO:0106263).
      proposed_replacement_terms:
        - id: GO:0047184
          label: 1-acylglycerophosphocholine O-acyltransferase activity
        - id: GO:0071617
          label: lysophospholipid acyltransferase activity
  - term:
      id: GO:0016746
      label: acyltransferase activity
    evidence_type: IEA
    original_reference_id: GO_REF:0000043
    review:
      summary: General acyltransferase activity term from UniProt keyword 
        mapping.
      action: MARK_AS_OVER_ANNOTATED
      reason: This is a broad parent term that doesn't convey the specific 
        substrate preference of LPCAT3. More informative terms exist 
        (GO:0047184, GO:0071617).
      proposed_replacement_terms:
        - id: GO:0047184
          label: 1-acylglycerophosphocholine O-acyltransferase activity
        - id: GO:0071617
          label: lysophospholipid acyltransferase activity
  - term:
      id: GO:0016020
      label: membrane
    evidence_type: IBA
    original_reference_id: GO_REF:0000033
    review:
      summary: General membrane annotation. LPCAT3 is indeed membrane-localized 
        but this term is too general.
      action: MODIFY
      reason: LPCAT3 is specifically localized to the endoplasmic reticulum 
        membrane (PMID:18195019). The term "membrane" is too general; GO:0005789
        (endoplasmic reticulum membrane) is more appropriate and already 
        annotated.
      proposed_replacement_terms:
        - id: GO:0005789
          label: endoplasmic reticulum membrane
      supported_by:
        - reference_id: PMID:18195019
          supporting_text: LPCAT3 is localized within the endoplasmic reticulum 
            and is primarily expressed in metabolic tissues including liver, 
            adipose, and pancreas.
  - term:
      id: GO:0005789
      label: endoplasmic reticulum membrane
    evidence_type: IEA
    original_reference_id: GO_REF:0000120
    review:
      summary: IEA annotation for ER membrane localization based on UniProt 
        subcellular location mapping.
      action: ACCEPT
      reason: This is the correct and specific localization for LPCAT3, 
        confirmed by direct experimental evidence (PMID:18195019).
      supported_by:
        - reference_id: PMID:18195019
          supporting_text: LPCAT3 is localized within the endoplasmic reticulum 
            and is primarily expressed in metabolic tissues including liver, 
            adipose, and pancreas.
  - term:
      id: GO:0005789
      label: endoplasmic reticulum membrane
    evidence_type: IDA
    original_reference_id: PMID:18195019
    review:
      summary: Direct experimental demonstration of ER localization by Zhao et 
        al. 2008.
      action: ACCEPT
      reason: Key primary evidence for ER localization from the study that 
        identified LPCAT3 as the major liver LPCAT enzyme.
      supported_by:
        - reference_id: PMID:18195019
          supporting_text: LPCAT3 is localized within the endoplasmic reticulum 
            and is primarily expressed in metabolic tissues including liver, 
            adipose, and pancreas.
  - term:
      id: GO:0005789
      label: endoplasmic reticulum membrane
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1482533
    review:
      summary: Reactome annotation for ER membrane localization in context of PC
        acyl chain remodeling pathway.
      action: ACCEPT
      reason: Consistent with direct experimental evidence for ER localization.
      supported_by:
        - reference_id: PMID:18195019
          supporting_text: LPCAT3 is localized within the endoplasmic reticulum 
            and is primarily expressed in metabolic tissues including liver, 
            adipose, and pancreas.
  - term:
      id: GO:0005789
      label: endoplasmic reticulum membrane
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1482547
    review:
      summary: Reactome annotation for ER membrane localization.
      action: ACCEPT
      reason: Consistent with experimental evidence.
      supported_by:
        - reference_id: PMID:18195019
          supporting_text: LPCAT3 is localized within the endoplasmic reticulum 
            and is primarily expressed in metabolic tissues including liver, 
            adipose, and pancreas.
  - term:
      id: GO:0005789
      label: endoplasmic reticulum membrane
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1482636
    review:
      summary: Reactome annotation for ER membrane localization.
      action: ACCEPT
      reason: Consistent with experimental evidence.
      supported_by:
        - reference_id: PMID:18195019
          supporting_text: LPCAT3 is localized within the endoplasmic reticulum 
            and is primarily expressed in metabolic tissues including liver, 
            adipose, and pancreas.
  - term:
      id: GO:0005789
      label: endoplasmic reticulum membrane
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1482646
    review:
      summary: Reactome annotation for ER membrane localization.
      action: ACCEPT
      reason: Consistent with experimental evidence.
      supported_by:
        - reference_id: PMID:18195019
          supporting_text: LPCAT3 is localized within the endoplasmic reticulum 
            and is primarily expressed in metabolic tissues including liver, 
            adipose, and pancreas.
  - term:
      id: GO:0005789
      label: endoplasmic reticulum membrane
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1482667
    review:
      summary: Reactome annotation for ER membrane localization.
      action: ACCEPT
      reason: Consistent with experimental evidence.
      supported_by:
        - reference_id: PMID:18195019
          supporting_text: LPCAT3 is localized within the endoplasmic reticulum 
            and is primarily expressed in metabolic tissues including liver, 
            adipose, and pancreas.
  - term:
      id: GO:0005789
      label: endoplasmic reticulum membrane
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1482691
    review:
      summary: Reactome annotation for ER membrane localization.
      action: ACCEPT
      reason: Consistent with experimental evidence.
      supported_by:
        - reference_id: PMID:18195019
          supporting_text: LPCAT3 is localized within the endoplasmic reticulum 
            and is primarily expressed in metabolic tissues including liver, 
            adipose, and pancreas.
  - term:
      id: GO:0016020
      label: membrane
    evidence_type: HDA
    original_reference_id: PMID:19946888
    review:
      summary: High-throughput proteomics study identified LPCAT3 in NK cell 
        membrane preparations.
      action: MODIFY
      reason: While this term is general and the HDA evidence is from a membrane
        proteomics study, the more specific ER membrane term (GO:0005789) is 
        preferred and already annotated. LPCAT3 is specifically localized to the
        ER membrane.
      proposed_replacement_terms:
        - id: GO:0005789
          label: endoplasmic reticulum membrane
      supported_by:
        - reference_id: PMID:19946888
          supporting_text: Mass spectrometric analysis identified 1843 proteins 
            with high confidence scores.
  - term:
      id: GO:0036152
      label: phosphatidylethanolamine acyl-chain remodeling
    evidence_type: IBA
    original_reference_id: GO_REF:0000033
    review:
      summary: LPCAT3 participates in PE acyl-chain remodeling as part of the 
        Lands cycle through its LPEAT activity.
      action: ACCEPT
      reason: LPCAT3 has demonstrated LPEAT activity (PMID:18772128, 
        PMID:18782225), enabling it to participate in PE remodeling. This is a 
        core function related to the Lands cycle.
      supported_by:
        - reference_id: PMID:18782225
          supporting_text: Knockdown of a human mboa-6 homologue, referred to as
            MBOAT5, also impaired the incorporation of PUFAs into PC, PS and PE 
            in HeLa cells.
  - term:
      id: GO:0036152
      label: phosphatidylethanolamine acyl-chain remodeling
    evidence_type: IEA
    original_reference_id: GO_REF:0000107
    review:
      summary: IEA annotation based on Ensembl Compara orthology to mouse.
      action: ACCEPT
      reason: Consistent with direct experimental evidence for LPEAT activity.
      supported_by:
        - reference_id: PMID:18782225
          supporting_text: Knockdown of a human mboa-6 homologue, referred to as
            MBOAT5, also impaired the incorporation of PUFAs into PC, PS and PE 
            in HeLa cells.
  - term:
      id: GO:0036152
      label: phosphatidylethanolamine acyl-chain remodeling
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1482839
    review:
      summary: Reactome pathway annotation for PE acyl-chain remodeling.
      action: ACCEPT
      reason: Consistent with LPEAT activity of LPCAT3.
      supported_by:
        - reference_id: PMID:18782225
          supporting_text: Knockdown of a human mboa-6 homologue, referred to as
            MBOAT5, also impaired the incorporation of PUFAs into PC, PS and PE 
            in HeLa cells.
  - term:
      id: GO:0036152
      label: phosphatidylethanolamine acyl-chain remodeling
    evidence_type: IMP
    original_reference_id: PMID:18782225
    review:
      summary: Matsuda et al. 2008 showed that MBOAT5 knockdown impairs PUFA 
        incorporation into PE.
      action: ACCEPT
      reason: Direct mutant phenotype evidence from knockdown experiments.
      supported_by:
        - reference_id: PMID:18782225
          supporting_text: Knockdown of a human mboa-6 homologue, referred to as
            MBOAT5, also impaired the incorporation of PUFAs into PC, PS and PE 
            in HeLa cells.
  - term:
      id: GO:0036152
      label: phosphatidylethanolamine acyl-chain remodeling
    evidence_type: IDA
    original_reference_id: PMID:18772128
    review:
      summary: Gijon et al. 2008 demonstrated LPEAT activity in neutrophils.
      action: ACCEPT
      reason: Direct biochemical evidence for PE remodeling activity.
      supported_by:
        - reference_id: PMID:18772128
          supporting_text: Human neutrophils express mRNA for these four 
            enzymes, and neutrophil microsomes incorporate arachidonoyl chains 
            into phosphatidylinositol, phosphatidylcholine, PS, and 
            phosphatidylethanolamine in a thimerosal-sensitive manner.
  - term:
      id: GO:0006656
      label: phosphatidylcholine biosynthetic process
    evidence_type: IBA
    original_reference_id: GO_REF:0000033
    review:
      summary: LPCAT3 contributes to PC biosynthesis through the Lands cycle 
        remodeling pathway, converting LPC to PC.
      action: ACCEPT
      reason: While the de novo Kennedy pathway is the primary biosynthetic 
        route, the Lands cycle (which LPCAT3 catalyzes) is responsible for 
        remodeling >50% of cellular PC and can be considered biosynthetic in the
        sense that it produces the final PC species. This is a core function.
      supported_by:
        - reference_id: PMID:18195019
          supporting_text: Phosphatidylcholine (PC) is synthesized through the 
            Kennedy pathway, but more than 50% of PC is remodeled through the 
            Lands cycle, i.e. the deacylation and reacylation of PC to attain 
            the final and proper fatty acids within PC.
  - term:
      id: GO:0030258
      label: lipid modification
    evidence_type: IBA
    original_reference_id: GO_REF:0000033
    review:
      summary: LPCAT3 modifies lipids by reacylating lysophospholipids.
      action: ACCEPT
      reason: This is a correct general parent term for the acyl-chain 
        remodeling activities of LPCAT3. The Lands cycle fundamentally involves 
        lipid modification.
      supported_by:
        - reference_id: PMID:18195019
          supporting_text: The reacylation step is catalyzed by 
            lysophosphatidylcholine acyltransferase (LPCAT), and we report here 
            the identification of a novel LPCAT, which we named LPCAT3.
  - term:
      id: GO:0036151
      label: phosphatidylcholine acyl-chain remodeling
    evidence_type: IEA
    original_reference_id: GO_REF:0000107
    review:
      summary: Core function of LPCAT3 in the Lands cycle - remodeling PC acyl 
        chains.
      action: ACCEPT
      reason: This is the primary biological process of LPCAT3. The enzyme 
        remodels PC by incorporating PUFAs at the sn-2 position.
      supported_by:
        - reference_id: PMID:18195019
          supporting_text: The reacylation step is catalyzed by 
            lysophosphatidylcholine acyltransferase (LPCAT), and we report here 
            the identification of a novel LPCAT, which we named LPCAT3.
  - term:
      id: GO:0036151
      label: phosphatidylcholine acyl-chain remodeling
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1482788
    review:
      summary: Reactome pathway annotation for PC acyl-chain remodeling.
      action: ACCEPT
      reason: Core function consistent with experimental evidence.
      supported_by:
        - reference_id: PMID:18195019
          supporting_text: The reacylation step is catalyzed by 
            lysophosphatidylcholine acyltransferase (LPCAT), and we report here 
            the identification of a novel LPCAT, which we named LPCAT3.
  - term:
      id: GO:0036151
      label: phosphatidylcholine acyl-chain remodeling
    evidence_type: IMP
    original_reference_id: PMID:18782225
    review:
      summary: Matsuda et al. 2008 showed knockdown of MBOAT5 reduced PUFA 
        incorporation into PC.
      action: ACCEPT
      reason: Direct mutant phenotype evidence for PC remodeling function.
      supported_by:
        - reference_id: PMID:18782225
          supporting_text: Knockdown of a human mboa-6 homologue, referred to as
            MBOAT5, also impaired the incorporation of PUFAs into PC, PS and PE 
            in HeLa cells.
  - term:
      id: GO:0036151
      label: phosphatidylcholine acyl-chain remodeling
    evidence_type: IDA
    original_reference_id: PMID:18195019
    review:
      summary: Zhao et al. 2008 directly demonstrated PC remodeling by LPCAT3.
      action: ACCEPT
      reason: Key primary evidence for PC remodeling function.
      supported_by:
        - reference_id: PMID:18195019
          supporting_text: In a human hepatoma Huh7 cells, RNA 
            interference-mediated knockdown of LPCAT3 resulted in virtually 
            complete loss of membrane LPCAT activity, suggesting that LPCAT3 is 
            primarily responsible for hepatic LPCAT activity.
  - term:
      id: GO:0036151
      label: phosphatidylcholine acyl-chain remodeling
    evidence_type: IDA
    original_reference_id: PMID:18772128
    review:
      summary: Gijon et al. 2008 demonstrated PC remodeling in neutrophils.
      action: ACCEPT
      reason: Direct biochemical evidence for PC remodeling.
      supported_by:
        - reference_id: PMID:18772128
          supporting_text: Human neutrophils express mRNA for these four 
            enzymes, and neutrophil microsomes incorporate arachidonoyl chains 
            into phosphatidylinositol, phosphatidylcholine, PS, and 
            phosphatidylethanolamine in a thimerosal-sensitive manner.
  - term:
      id: GO:0036151
      label: phosphatidylcholine acyl-chain remodeling
    evidence_type: ISS
    original_reference_id: GO_REF:0000024
    review:
      summary: ISS annotation based on mouse ortholog.
      action: ACCEPT
      reason: Consistent with direct experimental evidence.
      supported_by:
        - reference_id: PMID:18195019
          supporting_text: LPCAT3 is primarily responsible for hepatic LPCAT 
            activity.
  - term:
      id: GO:0036150
      label: phosphatidylserine acyl-chain remodeling
    evidence_type: IEA
    original_reference_id: GO_REF:0000107
    review:
      summary: LPCAT3 has LPSAT activity enabling PS remodeling.
      action: ACCEPT
      reason: Consistent with demonstrated LPSAT activity (PMID:18195019, 
        PMID:18772128, PMID:18782225).
      supported_by:
        - reference_id: PMID:18772128
          supporting_text: MBOAT5 prefers lysophosphatidylcholine and lyso-PS to
            incorporate linoleoyl and arachidonoyl chains.
  - term:
      id: GO:0036150
      label: phosphatidylserine acyl-chain remodeling
    evidence_type: TAS
    original_reference_id: Reactome:R-HSA-1482801
    review:
      summary: Reactome pathway annotation for PS acyl-chain remodeling.
      action: ACCEPT
      reason: Consistent with LPSAT activity.
      supported_by:
        - reference_id: PMID:18772128
          supporting_text: MBOAT5 prefers lysophosphatidylcholine and lyso-PS to
            incorporate linoleoyl and arachidonoyl chains.
  - term:
      id: GO:0036150
      label: phosphatidylserine acyl-chain remodeling
    evidence_type: IMP
    original_reference_id: PMID:18782225
    review:
      summary: Knockdown of MBOAT5 reduced PUFA incorporation into PS.
      action: ACCEPT
      reason: Direct mutant phenotype evidence.
      supported_by:
        - reference_id: PMID:18782225
          supporting_text: Knockdown of a human mboa-6 homologue, referred to as
            MBOAT5, also impaired the incorporation of PUFAs into PC, PS and PE 
            in HeLa cells.
  - term:
      id: GO:0036150
      label: phosphatidylserine acyl-chain remodeling
    evidence_type: IDA
    original_reference_id: PMID:18195019
    review:
      summary: Zhao et al. 2008 demonstrated LPSAT activity.
      action: ACCEPT
      reason: Direct biochemical evidence.
      supported_by:
        - reference_id: PMID:18782225
          supporting_text: These results indicate that human MBOAT5 is a 
            lysophospholipid acyltransferase acting preferentially on LPC, LPS 
            and LPE.
  - term:
      id: GO:0036150
      label: phosphatidylserine acyl-chain remodeling
    evidence_type: IDA
    original_reference_id: PMID:18772128
    review:
      summary: Gijon et al. 2008 demonstrated PS remodeling activity.
      action: ACCEPT
      reason: Direct MS-based biochemical evidence.
      supported_by:
        - reference_id: PMID:18772128
          supporting_text: MBOAT5 prefers lysophosphatidylcholine and lyso-PS to
            incorporate linoleoyl and arachidonoyl chains.
  - term:
      id: GO:0006629
      label: lipid metabolic process
    evidence_type: IEA
    original_reference_id: GO_REF:0000043
    review:
      summary: Very general term for lipid metabolism from UniProt keyword 
        mapping.
      action: MARK_AS_OVER_ANNOTATED
      reason: This term is too general. More specific terms like GO:0036151 
        (phosphatidylcholine acyl-chain remodeling) better capture LPCAT3's 
        function.
      proposed_replacement_terms:
        - id: GO:0036151
          label: phosphatidylcholine acyl-chain remodeling
  - term:
      id: GO:0008654
      label: phospholipid biosynthetic process
    evidence_type: IEA
    original_reference_id: GO_REF:0000043
    review:
      summary: LPCAT3 contributes to phospholipid production through the Lands 
        cycle.
      action: ACCEPT
      reason: While technically LPCAT3 is involved in remodeling rather than de 
        novo biosynthesis, the Lands cycle produces the final phospholipid 
        species with appropriate acyl chains. This general term is acceptable as
        a parent annotation.
      supported_by:
        - reference_id: PMID:18195019
          supporting_text: Phosphatidylcholine (PC) is synthesized through the 
            Kennedy pathway, but more than 50% of PC is remodeled through the 
            Lands cycle, i.e. the deacylation and reacylation of PC to attain 
            the final and proper fatty acids within PC.
  - term:
      id: GO:0006644
      label: phospholipid metabolic process
    evidence_type: IEA
    original_reference_id: GO_REF:0000041
    review:
      summary: General phospholipid metabolism term from UniPathway mapping.
      action: ACCEPT
      reason: LPCAT3 is centrally involved in phospholipid metabolism through 
        the Lands cycle. This is a correct general parent term.
      supported_by:
        - reference_id: PMID:18195019
          supporting_text: Our studies identify a long-sought enzyme that plays 
            a critical role in PC remodeling in metabolic tissues and provide an
            invaluable tool for future investigations on how PC remodeling may 
            potentially impact glucose and lipid homeostasis.
  - term:
      id: GO:0034378
      label: chylomicron assembly
    evidence_type: IEA
    original_reference_id: GO_REF:0000107
    review:
      summary: LPCAT3 in intestine provides PC for chylomicron surface assembly.
      action: KEEP_AS_NON_CORE
      reason: While this is a documented physiological role in enterocytes 
        (primarily from mouse studies), it is a downstream consequence of 
        LPCAT3's core phospholipid remodeling function rather than the core 
        molecular function. Intestine-specific Lpcat3 knockout in mice impairs 
        chylomicron secretion.
      additional_reference_ids:
        - doi:10.3389/fphar.2023.1097835
      supported_by:
        - reference_id: PMID:22511767
          supporting_text: Lipoprotein production studies indicated that 
            reductions in LPCAT3 enhanced assembly and secretion of 
            triglyceride-rich apoB-containing lipoproteins.
  - term:
      id: GO:0034378
      label: chylomicron assembly
    evidence_type: ISS
    original_reference_id: GO_REF:0000024
    review:
      summary: ISS annotation based on mouse ortholog data.
      action: KEEP_AS_NON_CORE
      reason: Downstream physiological consequence in intestine, not core 
        molecular function.
      supported_by:
        - reference_id: PMID:22511767
          supporting_text: Lipoprotein production studies indicated that 
            reductions in LPCAT3 enhanced assembly and secretion of 
            triglyceride-rich apoB-containing lipoproteins.
  - term:
      id: GO:0034379
      label: very-low-density lipoprotein particle assembly
    evidence_type: IEA
    original_reference_id: GO_REF:0000107
    review:
      summary: LPCAT3 in liver provides PC for VLDL assembly.
      action: KEEP_AS_NON_CORE
      reason: This is a downstream physiological consequence of LPCAT3's ER 
        membrane PC remodeling activity. LPCAT3 knockdown affects VLDL 
        production through altered LPC/PC levels and MTP expression 
        (PMID:22511767).
      supported_by:
        - reference_id: PMID:22511767
          supporting_text: Lipoprotein production studies indicated that 
            reductions in LPCAT3 enhanced assembly and secretion of 
            triglyceride-rich apoB-containing lipoproteins... hepatic LPCAT3 
            modulates VLDL production by regulating LysoPC levels and MTP 
            expression.
  - term:
      id: GO:0034379
      label: very-low-density lipoprotein particle assembly
    evidence_type: ISS
    original_reference_id: GO_REF:0000024
    review:
      summary: ISS annotation based on mouse ortholog.
      action: KEEP_AS_NON_CORE
      reason: Downstream physiological consequence in liver, not core molecular 
        function.
      supported_by:
        - reference_id: PMID:22511767
          supporting_text: Hepatic LPCAT3 modulates VLDL production by 
            regulating LysoPC levels and MTP expression.
  - term:
      id: GO:0036335
      label: intestinal stem cell homeostasis
    evidence_type: IEA
    original_reference_id: GO_REF:0000107
    review:
      summary: Mouse studies suggest LPCAT3 regulates intestinal stem cell 
        function through cholesterol metabolism.
      action: KEEP_AS_NON_CORE
      reason: This is a pleiotropic downstream effect in intestine, not the core
        molecular function. Evidence comes primarily from mouse knockout studies
        showing LPCAT3 influences a dietary-responsive phospholipid-cholesterol 
        axis affecting intestinal stem cells.
      supported_by:
        - reference_id: doi:10.1172/jci93616
          supporting_text: LPCAT3 regulates ER phospholipid composition which 
            modulates lipogenesis and membrane properties.
  - term:
      id: GO:0036335
      label: intestinal stem cell homeostasis
    evidence_type: ISS
    original_reference_id: GO_REF:0000024
    review:
      summary: ISS annotation from mouse ortholog.
      action: KEEP_AS_NON_CORE
      reason: Pleiotropic downstream effect, not core function.
      supported_by:
        - reference_id: doi:10.1172/jci93616
          supporting_text: LPCAT3 modulates membrane composition and signaling.
  - term:
      id: GO:0045540
      label: regulation of cholesterol biosynthetic process
    evidence_type: IEA
    original_reference_id: GO_REF:0000107
    review:
      summary: LPCAT3-mediated ER membrane remodeling affects SREBP processing 
        and cholesterol/lipid biosynthesis.
      action: KEEP_AS_NON_CORE
      reason: This is an indirect regulatory effect through ER membrane 
        composition affecting SREBP signaling. Not a direct molecular function 
        of LPCAT3.
      additional_reference_ids:
        - doi:10.1172/jci93616
      supported_by:
        - reference_id: doi:10.1172/jci93616
          supporting_text: LPCAT3 promotes processing of sterol regulatory 
            protein SREBF1 in hepatocytes, likely by facilitating the 
            translocation of SREBF1-SCAP complex from ER to the Golgi apparatus.
  - term:
      id: GO:0045540
      label: regulation of cholesterol biosynthetic process
    evidence_type: ISS
    original_reference_id: GO_REF:0000024
    review:
      summary: ISS annotation from mouse ortholog.
      action: KEEP_AS_NON_CORE
      reason: Indirect regulatory effect, not core function.
      supported_by:
        - reference_id: doi:10.1172/jci93616
          supporting_text: ER phospholipid composition modulates lipogenesis.
  - term:
      id: GO:0045797
      label: positive regulation of intestinal cholesterol absorption
    evidence_type: IEA
    original_reference_id: GO_REF:0000107
    review:
      summary: Mouse studies show LPCAT3 in enterocytes affects cholesterol 
        absorption.
      action: KEEP_AS_NON_CORE
      reason: Tissue-specific downstream effect in intestine through membrane 
        remodeling affecting passive diffusion of cholesterol.
      supported_by:
        - reference_id: doi:10.3892/ijmm.2024.5356
          supporting_text: LPCAT3 regulates the abundance of PCs containing 
            linoleate and arachidonate in enterocyte membranes, enabling passive
            diffusion of fatty acids and cholesterol across the membrane.
  - term:
      id: GO:0045797
      label: positive regulation of intestinal cholesterol absorption
    evidence_type: ISS
    original_reference_id: GO_REF:0000024
    review:
      summary: ISS annotation from mouse ortholog.
      action: KEEP_AS_NON_CORE
      reason: Tissue-specific downstream effect, not core function.
      supported_by:
        - reference_id: doi:10.3892/ijmm.2024.5356
          supporting_text: LPCAT3 affects enterocyte membrane composition and 
            cholesterol handling.
  - term:
      id: GO:0050728
      label: negative regulation of inflammatory response
    evidence_type: IEA
    original_reference_id: GO_REF:0000107
    review:
      summary: LPCAT3 may down-regulate inflammation by limiting arachidonic 
        acid availability for inflammatory eicosanoid synthesis.
      action: KEEP_AS_NON_CORE
      reason: This is an indirect effect through PUFA incorporation into 
        phospholipids, potentially limiting free AA for inflammatory mediator 
        synthesis. Evidence primarily from mouse studies.
      supported_by:
        - reference_id: doi:10.3892/ijmm.2024.5356
          supporting_text: LPCAT3 participates in mechanisms by which the liver 
            X receptor signaling pathway counteracts lipid-induced ER stress 
            response and inflammation. Down-regulates hepatic inflammation by 
            limiting arachidonic acid availability for synthesis of inflammatory
            eicosanoids.
  - term:
      id: GO:0050728
      label: negative regulation of inflammatory response
    evidence_type: ISS
    original_reference_id: GO_REF:0000024
    review:
      summary: ISS annotation from mouse ortholog.
      action: KEEP_AS_NON_CORE
      reason: Indirect effect through AA metabolism, not core function.
      supported_by:
        - reference_id: doi:10.3892/ijmm.2024.5356
          supporting_text: LPCAT3 limits arachidonic acid availability for 
            inflammatory eicosanoids.
  - term:
      id: GO:0090158
      label: endoplasmic reticulum membrane organization
    evidence_type: IEA
    original_reference_id: GO_REF:0000107
    review:
      summary: LPCAT3-mediated phospholipid remodeling affects ER membrane 
        composition and properties.
      action: KEEP_AS_NON_CORE
      reason: While LPCAT3 certainly affects ER membrane composition through its
        remodeling activity, "membrane organization" as a biological process is 
        an indirect consequence rather than a core function.
      supported_by:
        - reference_id: doi:10.1172/jci93616
          supporting_text: ER phospholipid composition modulates membrane 
            properties and lipogenesis.
  - term:
      id: GO:0090158
      label: endoplasmic reticulum membrane organization
    evidence_type: ISS
    original_reference_id: GO_REF:0000024
    review:
      summary: ISS annotation from mouse ortholog.
      action: KEEP_AS_NON_CORE
      reason: Indirect effect of phospholipid remodeling activity.
      supported_by:
        - reference_id: doi:10.1172/jci93616
          supporting_text: LPCAT3 shapes ER PC composition.
  - term:
      id: GO:1903573
      label: negative regulation of response to endoplasmic reticulum stress
    evidence_type: IEA
    original_reference_id: GO_REF:0000107
    review:
      summary: Mouse studies suggest LPCAT3 counteracts lipid-induced ER stress.
      action: KEEP_AS_NON_CORE
      reason: Indirect effect through ER membrane composition. Lpcat3 deficiency
        in mice exacerbates NASH partly through ER stress mechanisms.
      additional_reference_ids:
        - doi:10.1097/hep.0000000000000375
      supported_by:
        - reference_id: doi:10.1097/hep.0000000000000375
          supporting_text: Membrane phospholipid remodeling modulates NASH 
            progression by regulating mitochondrial homeostasis.
  - term:
      id: GO:1903573
      label: negative regulation of response to endoplasmic reticulum stress
    evidence_type: ISS
    original_reference_id: GO_REF:0000024
    review:
      summary: ISS annotation from mouse ortholog.
      action: KEEP_AS_NON_CORE
      reason: Indirect effect through membrane composition.
      supported_by:
        - reference_id: doi:10.1097/hep.0000000000000375
          supporting_text: Lpcat3 loss worsens NASH through mitochondrial and 
            membrane effects.
  - term:
      id: GO:1905885
      label: positive regulation of triglyceride transport
    evidence_type: IEA
    original_reference_id: GO_REF:0000107
    review:
      summary: LPCAT3 affects TG transport through effects on lipoprotein 
        assembly.
      action: KEEP_AS_NON_CORE
      reason: Indirect effect through lipoprotein biogenesis (chylomicron, 
        VLDL).
      supported_by:
        - reference_id: PMID:22511767
          supporting_text: In short, these results indicate that hepatic LPCAT3 
            modulates VLDL production by regulating LysoPC levels and MTP 
            expression.
  - term:
      id: GO:1905885
      label: positive regulation of triglyceride transport
    evidence_type: ISS
    original_reference_id: GO_REF:0000024
    review:
      summary: ISS annotation from mouse ortholog.
      action: KEEP_AS_NON_CORE
      reason: Indirect effect through lipoprotein metabolism.
      supported_by:
        - reference_id: PMID:22511767
          supporting_text: In short, these results indicate that hepatic LPCAT3 
            modulates VLDL production by regulating LysoPC levels and MTP 
            expression.
references:
  - id: GO_REF:0000024
    title: Manual transfer of experimentally-verified manual GO annotation data 
      to orthologs by curator judgment of sequence similarity
    findings: []
  - id: GO_REF:0000033
    title: Annotation inferences using phylogenetic trees
    findings: []
  - id: GO_REF:0000041
    title: Gene Ontology annotation based on UniPathway vocabulary mapping
    findings: []
  - id: GO_REF:0000043
    title: Gene Ontology annotation based on UniProtKB/Swiss-Prot keyword 
      mapping
    findings: []
  - id: GO_REF:0000107
    title: Automatic transfer of experimentally verified manual GO annotation 
      data to orthologs using Ensembl Compara
    findings: []
  - id: GO_REF:0000120
    title: Combined Automated Annotation using Multiple IEA Methods
    findings: []
  - id: PMID:18195019
    title: Identification and characterization of a major liver 
      lysophosphatidylcholine acyltransferase.
    findings:
      - statement: Identified LPCAT3 as the major hepatic 
          lysophosphatidylcholine acyltransferase. LPCAT3 belongs to the MBOAT 
          family, is ER-localized, and shows substrate preference for 
          unsaturated fatty acids. Knockdown in Huh7 cells virtually eliminates 
          membrane LPCAT activity.
        supporting_text: we report here the identification of a novel LPCAT, 
          which we named LPCAT3. LPCAT3 belongs to the membrane-bound 
          O-acyltransferase (MBOAT) family... In a human hepatoma Huh7 cells, 
          RNA interference-mediated knockdown of LPCAT3 resulted in virtually 
          complete loss of membrane LPCAT activity
  - id: PMID:18772128
    title: Lysophospholipid acyltransferases and arachidonate recycling in human
      neutrophils.
    findings:
      - statement: Characterized substrate specificity of MBOAT5/LPCAT3 using 
          MS-based assays. MBOAT5 prefers LPC and lyso-PS with linoleoyl and 
          arachidonoyl acyl-CoA donors. Activity is thimerosal-sensitive. 
          Implicates MBOAT5 in arachidonate recycling and regulation of free AA 
          for leukotriene synthesis.
        supporting_text: MBOAT5 prefers lysophosphatidylcholine and lyso-PS to 
          incorporate linoleoyl and arachidonoyl chains. MBOAT7 is a 
          lysophosphatidylinositol acyltransferase with remarkable specificity 
          for arachidonoyl-CoA. MBOAT5 and MBOAT7 are particularly susceptible 
          to inhibition by thimerosal.
  - id: PMID:18782225
    title: Member of the membrane-bound O-acyltransferase (MBOAT) family encodes
      a lysophospholipid acyltransferase with broad substrate specificity.
    findings:
      - statement: Demonstrated that MBOAT5/LPCAT3 is a lysophospholipid 
          acyltransferase acting on LPC, LPS, and LPE. Knockdown reduced PUFA 
          incorporation into PC, PS, and PE. Overexpression increased LPC, LPS, 
          and LPE acyltransferase activities but not LPIAT or LPAAT activities.
        supporting_text: These results indicate that human MBOAT5 is a 
          lysophospholipid acyltransferase acting preferentially on LPC, LPS and
          LPE.
  - id: PMID:19946888
    title: Defining the membrane proteome of NK cells.
    findings:
      - statement: High-throughput membrane proteomics study identifying LPCAT3 
          as a membrane protein in NK cells.
        supporting_text: Mass spectrometric analysis identified 1843 proteins 
          with high confidence scores.
  - id: PMID:22511767
    title: Lysophosphatidylcholine acyltransferase 3 knockdown-mediated liver 
      lysophosphatidylcholine accumulation promotes very low density lipoprotein
      production by enhancing microsomal triglyceride transfer protein 
      expression.
    findings:
      - statement: Demonstrated that LPCAT3 is the major hepatic isoform. 
          Knockdown increases LysoPC, decreases certain PC species, and reduces 
          hepatic triglycerides. Paradoxically, knockdown increases plasma TG 
          and apoB through enhanced VLDL secretion via increased MTP expression.
        supporting_text: we found that LPCAT3 is the major hepatic isoform, and 
          its knockdown significantly reduces hepatic LPCAT activity... these 
          results indicate that hepatic LPCAT3 modulates VLDL production by 
          regulating LysoPC levels and MTP expression
  - id: Reactome:R-HSA-1482533
    title: 2-acyl LPC is acylated to PC by LPCAT
    findings: []
  - id: Reactome:R-HSA-1482547
    title: 1-acyl LPC is acylated to PC by LPCAT
    findings: []
  - id: Reactome:R-HSA-1482636
    title: 1-acyl LPS is acylated to PS by LPSAT
    findings: []
  - id: Reactome:R-HSA-1482646
    title: 2-acyl LPE is acylated to PE by LPEAT
    findings: []
  - id: Reactome:R-HSA-1482667
    title: 1-acyl LPE is acylated to PE by LPEAT
    findings: []
  - id: Reactome:R-HSA-1482691
    title: 2-acyl LPS is acylated to PS by LPSAT
    findings: []
  - id: Reactome:R-HSA-1482788
    title: Acyl chain remodelling of PC
    findings: []
  - id: Reactome:R-HSA-1482801
    title: Acyl chain remodelling of PS
    findings: []
  - id: Reactome:R-HSA-1482839
    title: Acyl chain remodelling of PE
    findings: []
  - id: file:human/LPCAT3/LPCAT3-deep-research-falcon.md
    title: Deep research report on LPCAT3
    findings: []
core_functions:
  - molecular_function:
      id: GO:0047184
      label: 1-acylglycerophosphocholine O-acyltransferase activity
    description: Primary enzymatic activity of LPCAT3. Catalyzes transfer of 
      acyl groups (preferentially PUFAs like arachidonic acid) from acyl-CoA to 
      1-acyl-lysophosphatidylcholine to form phosphatidylcholine. This is the 
      reacylation step of the Lands cycle.
    locations:
      - id: GO:0005789
        label: endoplasmic reticulum membrane
    directly_involved_in:
      - id: GO:0036151
        label: phosphatidylcholine acyl-chain remodeling
  - molecular_function:
      id: GO:0071617
      label: lysophospholipid acyltransferase activity
    description: Broader term capturing LPCAT3's activity on multiple 
      lysophospholipid substrates including LPC, LPE, and LPS.
    locations:
      - id: GO:0005789
        label: endoplasmic reticulum membrane
  - molecular_function:
      id: GO:0106262
      label: 1-acylglycerophosphoethanolamine O-acyltransferase activity
    description: Secondary but important activity - remodeling PE with PUFAs, 
      particularly relevant for ferroptosis where AA-PE/AdA-PE are peroxidation 
      substrates.
    locations:
      - id: GO:0005789
        label: endoplasmic reticulum membrane
    directly_involved_in:
      - id: GO:0036152
        label: phosphatidylethanolamine acyl-chain remodeling
proposed_new_terms: []
suggested_questions:
  - question: What is the relative contribution of LPCAT3 vs other LPCAT 
      isoforms in different tissues and cell types?
  - question: How does the CEPT1-LPCAT3 interaction regulate ferroptosis 
      sensitivity in different disease contexts?
  - question: Are there human genetic variants in LPCAT3 associated with 
      metabolic disease, NASH, or ferroptosis-related conditions?
suggested_experiments:
  - description: CRISPR knockout studies in human hepatocytes to directly assess
      LPCAT3 contribution to ferroptosis sensitivity
    hypothesis: LPCAT3 knockout will confer resistance to ferroptosis inducers 
      by reducing PUFA-PE substrate availability for lipid peroxidation.
  - description: Lipidomics profiling of AA-PE/AdA-PE species in LPCAT3 
      knockdown cells to quantify the ferroptosis substrate pool
    hypothesis: LPCAT3 knockdown will specifically reduce AA-PE and AdA-PE 
      species that serve as ferroptosis substrates.
  - description: Structural studies with different lysophospholipid substrates 
      to understand headgroup selectivity
    hypothesis: The substrate binding pocket geometry determines preference for 
      LPC over LPE and LPS substrates.
tags:
  - ferroptosis

LPCAT3

Gene Description

Existing Annotations Review

Core Functions

Primary enzymatic activity of LPCAT3. Catalyzes transfer of acyl groups (preferentially PUFAs like arachidonic acid) from acyl-CoA to 1-acyl-lysophosphatidylcholine to form phosphatidylcholine. This is the reacylation step of the Lands cycle.

Broader term capturing LPCAT3's activity on multiple lysophospholipid substrates including LPC, LPE, and LPS.

Secondary but important activity - remodeling PE with PUFAs, particularly relevant for ferroptosis where AA-PE/AdA-PE are peroxidation substrates.

References

Suggested Questions for Experts

Suggested Experiments

Tags

📚 Additional Documentation

Deep Research Falcon

Question

Gene Research for Functional Annotation

⚠️ CRITICAL: Gene/Protein Identification Context

Target Gene/Protein Identity (from UniProt):

MANDATORY VERIFICATION STEPS:

If Gene Symbol is Ambiguous or You Cannot Find Relevant Literature:

Research Target:

Output

Gene Research for Functional Annotation

⚠️ CRITICAL: Gene/Protein Identification Context

Target Gene/Protein Identity (from UniProt):

MANDATORY VERIFICATION STEPS:

If Gene Symbol is Ambiguous or You Cannot Find Relevant Literature:

Research Target:

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