{"gene":"GPAT4","run_date":"2026-06-10T01:55:21","timeline":{"discoveries":[{"year":2008,"finding":"AGPAT6 (GPAT4) is a microsomal glycerol-3-phosphate acyltransferase (GPAT), not an AGPAT. Membranes from HEK293 cells overexpressing human AGPAT6 showed higher GPAT activity but not AGPAT activity. Purified AGPAT6 protein possessed GPAT activity. The enzyme is sensitive to N-ethylmaleimide (a sulfhydryl-modifying reagent), is active against both saturated and unsaturated long-chain fatty acyl-CoAs, and overexpression increased lysophosphatidic acid and phosphatidic acid levels. Mammary epithelial cell membranes from Agpat6-deficient mice showed markedly reduced GPAT activity.","method":"In vitro GPAT/AGPAT activity assays with purified protein and overexpression in HEK293 cells; siRNA knockdown; [13C7]oleic acid labeling with mass spectrometry; NEM sensitivity assay","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro enzymatic activity with purified protein, substrate specificity assays, isotope labeling/MS, KO mouse validation, siRNA knockdown, multiple orthogonal methods","pmids":["18238778"],"is_preprint":false},{"year":2008,"finding":"GPAT4 (misnamed Agpat6) encodes an NEM-sensitive GPAT, not an AGPAT. In liver and brown adipose tissue from Agpat6-/- mice, NEM-sensitive GPAT specific activity was 65% lower than in wild-type mice, but AGPAT specific activity was unchanged. Overexpression of Agpat6 in Cos-7 cells increased NEM-sensitive GPAT activity but not AGPAT activity. Lipid intermediates (LPA, PA, DAG) initiated by GPAT4 lie in different cellular pools than those initiated by GPAT1.","method":"GPAT/AGPAT activity assays in tissues from knockout mice and overexpressing cells; [14C]oleate incorporation into lipid intermediates in Cos-7 cells","journal":"Journal of lipid research","confidence":"High","confidence_rationale":"Tier 1 / Strong — in vitro enzymatic assays with KO mouse tissues and overexpression, isotope labeling, two orthogonal methods, independently corroborated by PMID:18238778","pmids":["18192653"],"is_preprint":false},{"year":2006,"finding":"AGPAT6 (GPAT4) localizes exclusively to the endoplasmic reticulum in mammalian cells. Agpat6-/- mice show defective lactation with dramatically reduced lipid droplets in mammary epithelial cells and milk depleted of diacylglycerols and triacylglycerols, establishing its essential role in milk fat production.","method":"Gene-trap knockout mice; histology of mammary glands; northern blot; lipid analysis of milk; subcellular localization by ER marker co-localization","journal":"Journal of lipid research","confidence":"High","confidence_rationale":"Tier 2 / Strong — KO mouse with defined cellular phenotype (lipid droplet loss, milk fat depletion), ER localization by direct imaging, replicated by subsequent studies","pmids":["16449762"],"is_preprint":false},{"year":2010,"finding":"GPAT3 and GPAT4 are both phosphorylated by insulin at Ser and Thr residues, leading to increased GPAT activity that is sensitive to the PI3K inhibitor wortmannin, linking insulin signaling to microsomal GPAT activity. Knockdown of GPAT3 but not GPAT4 in 3T3-L1 adipocytes significantly decreased GPAT activity and inhibited lipid accumulation and adipogenic marker expression during differentiation.","method":"shRNA knockdown in 3T3-L1 adipocytes; overexpression in insect and mammalian cells; phosphorylation assays with insulin treatment and wortmannin inhibition; GPAT activity assays; lipid accumulation and gene expression analysis","journal":"Journal of lipid research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — direct phosphorylation assay and activity measurement, single lab, two orthogonal methods (activity assay + KD phenotype)","pmids":["20181984"],"is_preprint":false},{"year":2013,"finding":"GPAT1, but not GPAT4, is required to incorporate de novo synthesized fatty acids into triacylglycerol and to divert them away from β-oxidation. In primary hepatocytes from Gpat4-/- mice, incorporation of de novo synthesized fatty acid into TAG was similar to wild-type, but Gpat1-/- hepatocytes showed doubled fatty acid oxidation. This establishes that GPAT1 and GPAT4 metabolize distinct fatty acid pools in liver.","method":"Primary hepatocytes from Gpat1-/-, Gpat4-/-, and control mice; de novo fatty acid synthesis labeling; exogenous fatty acid incorporation assays; acylcarnitine measurements in vivo (fasting/refeeding protocol)","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — KO mouse hepatocytes with multiple metabolic readouts, in vitro and in vivo corroboration, multiple orthogonal methods","pmids":["23908354"],"is_preprint":false},{"year":2015,"finding":"GPAT4 limits oxidation of exogenous fatty acids in brown adipocytes. Gpat4-/- brown adipocytes incorporated 33% less fatty acid into triacylglycerol and 46% more into β-oxidation pathway, specifically through increased oxidation of exogenous (not de novo) fatty acids. GPAT4 comprises ~65% of total GPAT activity in brown adipose tissue.","method":"Gpat4-/- mice; metabolic rate measurements; neonatal BAT preadipocytes differentiated to adipocytes; fatty acid incorporation and oxidation assays; GPAT activity measurements; gene expression analysis","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 2 / Strong — KO mouse with defined cellular phenotype, in vitro adipocyte assays, multiple metabolic readouts","pmids":["25918168"],"is_preprint":false},{"year":2019,"finding":"CHP1 (calcineurin B homologous protein 1) binds and activates GPAT4. CHP1 must be N-myristoylated to activate GPAT4, forming a key molecular interface. Loss of CHP1 severely reduces fatty acid incorporation into glycerolipids in mammalian cells and invertebrates. Upon CHP1 loss, the peroxisomal enzyme GNPAT partially compensates for reduced ER lipid synthesis.","method":"CRISPR-based genetic screens; unbiased lipidomics; Co-IP/binding assays; CHP1 N-myristoylation mutants; fatty acid incorporation assays; invertebrate model validation","journal":"Molecular cell","confidence":"High","confidence_rationale":"Tier 2 / Strong — CRISPR screen plus mechanistic follow-up with mutagenesis (N-myristoylation), lipidomics, cross-species validation, multiple orthogonal methods","pmids":["30846317"],"is_preprint":false},{"year":2020,"finding":"GPAT4 synthesizes saturated lysophosphatidic acids (e.g., 1-stearoyl-LPA) at the contact site between omegasomes and the mitochondria-associated membrane (MAM). Accumulation of these saturated LPAs causes abnormal omegasome formation, leading to accumulation of autophagosomal precursor isolation membranes and inhibition of autophagic flux, contributing to vascular calcification and apoptosis in vascular smooth muscle cells.","method":"SCD-knockout VSMC model; lipid metabolite analysis; autophagic flux assays; omegasome imaging; GPAT4 functional studies in VSMCs","journal":"iScience","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — defined mechanistic pathway with lipid metabolite analysis and autophagy readouts, single lab, moderate mechanistic depth in abstract","pmids":["32408172"],"is_preprint":false},{"year":2022,"finding":"PPARγ acts as a transcription factor for AGPAT6 (GPAT4) via an RXRα binding site at -96 bp of the AGPAT6 promoter. Acetate stimulation increases the interaction between PPARγ and AGPAT6 promoter. AGPAT6 knockdown decreased acetate-induced mTORC1 signaling phosphorylation and intracellular TAG content; this was rescued by exogenous 16:0,18:1-phosphatidic acid, demonstrating that AGPAT6 activates mTORC1 by generating PA.","method":"Luciferase reporter assay with promoter deletions/mutations; siRNA knockdown; phosphatidic acid rescue experiment; western blot for mTORC1 signaling","journal":"The Journal of dairy research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — luciferase reporter with deletion mapping plus PA rescue experiment, single lab, two orthogonal methods","pmids":["36398416"],"is_preprint":false},{"year":2025,"finding":"GPAT4 deficiency in endocardial cells provokes ER stress and enhances ER-mitochondria (ER-mito) communications, leading to mitochondrial DNA (mtDNA) escape. The escaped mtDNA activates the cGAS-STING pathway to stimulate type-I interferon response, which impairs heart development. Abolishment of cGAS-STING-type-I-interferon signaling rescued heart defects in Gpat4 deletion mice.","method":"Gpat4 global and tissue-specific knockout mice; ER stress markers; ER-mitochondria contact site imaging; mtDNA escape assay; cGAS-STING pathway analysis; genetic rescue with cGAS-STING pathway ablation","journal":"Nature communications","confidence":"High","confidence_rationale":"Tier 2 / Strong — tissue-specific KO mice with defined molecular pathway (ER stress → mtDNA escape → cGAS-STING → IFN), genetic epistasis rescue, multiple orthogonal methods","pmids":["40199910"],"is_preprint":false},{"year":2025,"finding":"CPT2 knockdown in colorectal cancer cells induces GPAT4-dependent accumulation of glycerophospholipids (primarily phosphatidylcholine and phosphatidylethanolamine), which promote autophagosome maturation and selective autophagy (lipophagy).","method":"CPT2 knockdown; metabolite analysis; transcriptomic analysis; in vitro and in vivo proliferation assays","journal":"Communications biology","confidence":"Low","confidence_rationale":"Tier 3 / Weak — GPAT4 role inferred from metabolite analysis after CPT2 KD, single lab, GPAT4 not directly manipulated in the abstract","pmids":["41107458"],"is_preprint":false},{"year":2024,"finding":"GPAT4 diffuses in the ER membrane and translocates to lipid droplets (LDs) via seipin-containing ER-LD bridges (lateral transfer at membrane contact sites). Upon reaching the LD surface, GPAT4 becomes nano-confined, consistent with selective partitioning into nanoscale membrane domains that concentrate it at the LD surface.","method":"MINFLUX and HILO single-molecule tracking with machine learning; comparison with HSD17B13 and LiveDrop model cargo; seipin-containing bridge identification","journal":"bioRxiv","confidence":"Medium","confidence_rationale":"Tier 1 / Weak — single-molecule super-resolution imaging (MINFLUX) is high-tier method, but GPAT4 tracking is one of several cargoes examined and preprint is not peer-reviewed","pmids":["bio_10.1101_2024.08.27.610018"],"is_preprint":true},{"year":2026,"finding":"FXR (farnesoid X receptor) transcriptionally inhibits GPAT4 expression. Dual-luciferase reporter assay confirmed FXR as a transcriptional repressor of GPAT4. FXR activation reduced lipid droplet accumulation by inhibiting GPAT4 in hepatic cell models.","method":"Dual-luciferase reporter assay; siRNA knockdown; western blot; HFD mouse model and oleic acid-induced HepG2 cell model","journal":"Chinese medicine","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — luciferase reporter directly mapping FXR-GPAT4 transcriptional regulation, siRNA knockdown with lipid phenotype, single lab","pmids":["41530783"],"is_preprint":false}],"current_model":"GPAT4 (originally misnamed AGPAT6) is an NEM-sensitive, ER-resident glycerol-3-phosphate acyltransferase that catalyzes the first committed step of de novo glycerolipid synthesis by acylating glycerol-3-phosphate to produce lysophosphatidic acid (LPA), using both saturated and unsaturated long-chain fatty acyl-CoAs as substrates; it is activated by the N-myristoylated adaptor protein CHP1, phosphorylated and activated downstream of insulin/PI3K signaling, traffics from the ER to lipid droplets via seipin-containing ER-LD bridges, and its generated phosphatidic acid activates mTORC1, while its absence in brown adipocytes increases fatty acid β-oxidation, in liver specifically channels de novo (but not exogenous) fatty acids away from oxidation, and in endocardial cells maintains ER homeostasis by preventing ER stress-induced mtDNA escape and cGAS-STING-mediated type-I interferon activation."},"narrative":{"mechanistic_narrative":"GPAT4 (originally misnamed AGPAT6) is an N-ethylmaleimide-sensitive, endoplasmic reticulum-resident glycerol-3-phosphate acyltransferase that catalyzes the first committed step of de novo glycerolipid synthesis, acylating glycerol-3-phosphate with saturated or unsaturated long-chain acyl-CoAs to generate lysophosphatidic acid and, downstream, phosphatidic acid [PMID:18238778, PMID:18192653, PMID:16449762]. Enzymatic activity requires the N-myristoylated adaptor CHP1, which binds and activates GPAT4 at the ER, and is further enhanced by insulin-stimulated Ser/Thr phosphorylation in a PI3K-dependent manner [PMID:30846317, PMID:20181984]. The lipid intermediates GPAT4 produces define a metabolic pool distinct from that of GPAT1: GPAT4 governs acylation of exogenous fatty acids in brown adipocytes, such that its loss diverts fatty acids from triacylglycerol storage into β-oxidation, whereas GPAT1 handles de novo synthesized fatty acids in liver [PMID:25918168, PMID:23908354]. The phosphatidic acid generated by GPAT4 acts as a signaling lipid that activates mTORC1 [PMID:36398416]. GPAT4 transcription is positively controlled by PPARγ and repressed by FXR, coupling its expression to lipid-droplet accumulation in hepatic and secretory cells [PMID:36398416, PMID:41530783]. Beyond catalysis, GPAT4 maintains ER homeostasis: its deficiency in endocardial cells provokes ER stress, enhanced ER–mitochondria contact, mtDNA escape, and cGAS-STING-driven type-I interferon signaling that impairs heart development, a defect rescued by ablating cGAS-STING signaling [PMID:40199910]. GPAT4 also traffics from the ER to lipid droplets through seipin-containing ER-LD bridges [PMID:bio_10.1101_2024.08.27.610018].","teleology":[{"year":2006,"claim":"Before its enzymatic identity was known, knockout phenotyping established that this ER-localized protein is essential for milk fat production, pinpointing a physiological role in glycerolipid synthesis.","evidence":"Gene-trap knockout mice with mammary histology, milk lipid analysis, and ER marker co-localization","pmids":["16449762"],"confidence":"High","gaps":["Did not define the biochemical reaction catalyzed","Mechanism of lipid-droplet loss in mammary epithelium not resolved"]},{"year":2008,"claim":"Resolved the long-standing misannotation by demonstrating the enzyme is a GPAT, not an AGPAT, fixing the first committed step of de novo glycerolipid synthesis as its function.","evidence":"In vitro GPAT/AGPAT assays with purified protein and overexpression, isotope labeling/MS, NEM sensitivity, and KO mouse tissue activity in HEK293/Cos-7 systems","pmids":["18238778","18192653"],"confidence":"High","gaps":["How GPAT4-initiated intermediates are channeled to distinct cellular pools not yet defined","Regulatory inputs unknown"]},{"year":2010,"claim":"Connected GPAT4 activity to hormonal control by showing insulin stimulates its phosphorylation and activity via PI3K.","evidence":"Phosphorylation assays with insulin/wortmannin and GPAT activity measurement in adipocytes and overexpression systems","pmids":["20181984"],"confidence":"Medium","gaps":["Specific kinase and phosphosites not identified","GPAT4 knockdown alone did not reduce adipocyte GPAT activity, leaving its quantitative contribution to adipogenesis unclear"]},{"year":2013,"claim":"Established functional non-redundancy between GPAT isoforms by showing GPAT4, unlike GPAT1, does not channel de novo fatty acids into TAG in liver.","evidence":"Primary hepatocytes from Gpat1-/- and Gpat4-/- mice with de novo and exogenous fatty acid labeling plus in vivo acylcarnitine measurement","pmids":["23908354"],"confidence":"High","gaps":["Structural basis for substrate-pool selectivity unknown"]},{"year":2015,"claim":"Defined GPAT4's tissue-specific substrate preference by showing it limits oxidation of exogenous fatty acids in brown adipocytes, complementing the liver finding.","evidence":"Gpat4-/- brown adipocytes with fatty acid incorporation/oxidation assays and metabolic rate measurements","pmids":["25918168"],"confidence":"High","gaps":["How exogenous vs de novo fatty acids are physically segregated to GPAT4 not resolved"]},{"year":2019,"claim":"Identified the activating partner of GPAT4, showing N-myristoylated CHP1 binds and is required to drive ER lipid synthesis.","evidence":"CRISPR screens, Co-IP, CHP1 N-myristoylation mutants, lipidomics, and invertebrate validation","pmids":["30846317"],"confidence":"High","gaps":["Structural detail of the CHP1-GPAT4 interface not solved","How CHP1 binding alters catalysis mechanistically unclear"]},{"year":2020,"claim":"Linked GPAT4-produced saturated LPAs at omegasome/MAM contact sites to autophagy regulation, extending its role beyond bulk lipid storage.","evidence":"SCD-knockout VSMC model with lipid metabolite analysis, omegasome imaging, and autophagic flux assays","pmids":["32408172"],"confidence":"Medium","gaps":["GPAT4 not directly perturbed to confirm causality","Single lab; effect on autophagy not validated in other cell types"]},{"year":2022,"claim":"Defined transcriptional and signaling outputs by showing PPARγ drives GPAT4 expression and that its phosphatidic acid product activates mTORC1.","evidence":"Luciferase reporter promoter mapping, siRNA knockdown, and PA rescue with mTORC1 western blots","pmids":["36398416"],"confidence":"Medium","gaps":["Direct binding of GPAT4-derived PA to mTORC1 components not shown","Single cell context"]},{"year":2025,"claim":"Revealed a homeostatic role beyond metabolism by showing GPAT4 loss triggers ER stress, mtDNA escape, and cGAS-STING-driven interferon signaling that disrupts heart development.","evidence":"Gpat4 global and tissue-specific KO mice with ER stress markers, ER-mito contact imaging, mtDNA escape assays, and genetic cGAS-STING rescue","pmids":["40199910"],"confidence":"High","gaps":["How loss of GPAT4 catalysis specifically alters ER membrane lipid composition to provoke stress not defined","Whether this pathway operates in non-cardiac tissues unknown"]},{"year":2025,"claim":"Implicated GPAT4-dependent glycerophospholipid accumulation in autophagosome maturation downstream of CPT2 loss in colorectal cancer.","evidence":"CPT2 knockdown with metabolite/transcriptomic analysis and proliferation assays","pmids":["41107458"],"confidence":"Low","gaps":["GPAT4 not directly manipulated; role inferred from metabolite changes","Causal contribution to autophagy not established"]},{"year":2026,"claim":"Added a second transcriptional regulator by showing FXR represses GPAT4 to limit hepatic lipid-droplet accumulation.","evidence":"Dual-luciferase reporter, siRNA knockdown, and HFD mouse/HepG2 lipid phenotyping","pmids":["41530783"],"confidence":"Medium","gaps":["Direct FXR binding element on the GPAT4 promoter not mapped","Single lab"]},{"year":null,"claim":"The structural basis of GPAT4 catalysis and its activation by CHP1, and the mechanism by which it selectively partitions distinct fatty acid pools across tissues, remain unresolved.","evidence":"","pmids":[],"confidence":"High","gaps":["No high-resolution structure of GPAT4 or the CHP1-GPAT4 complex","Molecular basis for de novo vs exogenous fatty acid channeling unknown","Direct mechanism coupling GPAT4 activity to ER membrane homeostasis undefined"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0016740","term_label":"transferase activity","supporting_discovery_ids":[0,1,6]}],"localization":[{"term_id":"GO:0005783","term_label":"endoplasmic reticulum","supporting_discovery_ids":[2,11]},{"term_id":"GO:0005811","term_label":"lipid droplet","supporting_discovery_ids":[11]}],"pathway":[],"complexes":[],"partners":["CHP1"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q86UL3","full_name":"Glycerol-3-phosphate acyltransferase 4","aliases":["1-acylglycerol-3-phosphate O-acyltransferase 6","1-AGP acyltransferase 6","1-AGPAT 6","Acyl-CoA:glycerol-3-phosphate acyltransferase 4","Lysophosphatidic acid acyltransferase zeta","LPAAT-zeta","Testis spermatogenesis apoptosis-related protein 7","TSARG7"],"length_aa":456,"mass_kda":52.1,"function":"Converts glycerol-3-phosphate to 1-acyl-sn-glycerol-3-phosphate (lysophosphatidic acid or LPA) by incorporating an acyl moiety at the sn-1 position of the glycerol backbone (PubMed:18238778). Active against both saturated and unsaturated long-chain fatty acyl-CoAs (PubMed:18238778). Protects cells against lipotoxicity (PubMed:30846318)","subcellular_location":"Endoplasmic reticulum membrane","url":"https://www.uniprot.org/uniprotkb/Q86UL3/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/GPAT4","classification":"Not Classified","n_dependent_lines":7,"n_total_lines":1208,"dependency_fraction":0.005794701986754967},"opencell":{"profiled":true,"resolved_as":"","ensg_id":"ENSG00000158669","cell_line_id":"CID000327","localizations":[{"compartment":"er","grade":3},{"compartment":"vesicles","grade":1}],"interactors":[{"gene":"AGPAT6","stoichiometry":10.0},{"gene":"CHP1","stoichiometry":10.0}],"url":"https://opencell.sf.czbiohub.org/target/CID000327","total_profiled":1310},"omim":[{"mim_id":"611396","title":"ADIPOGENIN; ADIG","url":"https://www.omim.org/entry/611396"},{"mim_id":"606158","title":"BSCL2 GENE; BSCL2","url":"https://www.omim.org/entry/606158"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"","locations":[],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/GPAT4"},"hgnc":{"alias_symbol":["DKFZp586M1819","LPAAT-zeta","TSARG7"],"prev_symbol":["AGPAT6"]},"alphafold":{"accession":"Q86UL3","domains":[{"cath_id":"-","chopping":"165-427","consensus_level":"high","plddt":92.8426,"start":165,"end":427}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q86UL3","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q86UL3-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q86UL3-F1-predicted_aligned_error_v6.png","plddt_mean":85.31},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=GPAT4","jax_strain_url":"https://www.jax.org/strain/search?query=GPAT4"},"sequence":{"accession":"Q86UL3","fasta_url":"https://rest.uniprot.org/uniprotkb/Q86UL3.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q86UL3/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q86UL3"}},"corpus_meta":[{"pmid":"18492828","id":"PMC_18492828","title":"ACSL1, AGPAT6, FABP3, LPIN1, and SLC27A6 are the most abundant isoforms in bovine mammary tissue and their expression is affected by stage of lactation.","date":"2008","source":"The Journal of nutrition","url":"https://pubmed.ncbi.nlm.nih.gov/18492828","citation_count":183,"is_preprint":false},{"pmid":"18238778","id":"PMC_18238778","title":"AGPAT6 is a novel microsomal glycerol-3-phosphate acyltransferase.","date":"2008","source":"The Journal of biological chemistry","url":"https://pubmed.ncbi.nlm.nih.gov/18238778","citation_count":116,"is_preprint":false},{"pmid":"18192653","id":"PMC_18192653","title":"Identification of a novel sn-glycerol-3-phosphate acyltransferase isoform, GPAT4, as the enzyme deficient in Agpat6-/- mice.","date":"2008","source":"Journal of lipid research","url":"https://pubmed.ncbi.nlm.nih.gov/18192653","citation_count":104,"is_preprint":false},{"pmid":"16449762","id":"PMC_16449762","title":"Agpat6--a novel lipid biosynthetic gene required for triacylglycerol production in mammary epithelium.","date":"2006","source":"Journal of lipid research","url":"https://pubmed.ncbi.nlm.nih.gov/16449762","citation_count":101,"is_preprint":false},{"pmid":"20181984","id":"PMC_20181984","title":"GPAT3 and GPAT4 are regulated by insulin-stimulated phosphorylation and play distinct roles in adipogenesis.","date":"2010","source":"Journal of lipid research","url":"https://pubmed.ncbi.nlm.nih.gov/20181984","citation_count":94,"is_preprint":false},{"pmid":"30846317","id":"PMC_30846317","title":"CHP1 Regulates Compartmentalized Glycerolipid Synthesis by Activating GPAT4.","date":"2019","source":"Molecular cell","url":"https://pubmed.ncbi.nlm.nih.gov/30846317","citation_count":85,"is_preprint":false},{"pmid":"23908354","id":"PMC_23908354","title":"Glycerol-3-phosphate acyltransferase (GPAT)-1, but not GPAT4, incorporates newly synthesized fatty acids into triacylglycerol and diminishes fatty acid oxidation.","date":"2013","source":"The Journal of biological 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droplets","date":"2024-08-28","source":"bioRxiv","url":"https://doi.org/10.1101/2024.08.27.610018","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":13707,"output_tokens":3896,"usd":0.04978,"stage1_stop_reason":"end_turn"},"stage2":{"model":"claude-opus-4-8","input_tokens":11714,"output_tokens":3512,"usd":0.073185,"stage2_stop_reason":"end_turn"},"total_usd":0.122965,"stage1_batch_id":"msgbatch_01DUPACZi7AAWwuZiUjseQF4","stage2_batch_id":"msgbatch_018yt7chE3f48PEFtDwtj6AE","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2008,\n      \"finding\": \"AGPAT6 (GPAT4) is a microsomal glycerol-3-phosphate acyltransferase (GPAT), not an AGPAT. Membranes from HEK293 cells overexpressing human AGPAT6 showed higher GPAT activity but not AGPAT activity. Purified AGPAT6 protein possessed GPAT activity. The enzyme is sensitive to N-ethylmaleimide (a sulfhydryl-modifying reagent), is active against both saturated and unsaturated long-chain fatty acyl-CoAs, and overexpression increased lysophosphatidic acid and phosphatidic acid levels. Mammary epithelial cell membranes from Agpat6-deficient mice showed markedly reduced GPAT activity.\",\n      \"method\": \"In vitro GPAT/AGPAT activity assays with purified protein and overexpression in HEK293 cells; siRNA knockdown; [13C7]oleic acid labeling with mass spectrometry; NEM sensitivity assay\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro enzymatic activity with purified protein, substrate specificity assays, isotope labeling/MS, KO mouse validation, siRNA knockdown, multiple orthogonal methods\",\n      \"pmids\": [\"18238778\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2008,\n      \"finding\": \"GPAT4 (misnamed Agpat6) encodes an NEM-sensitive GPAT, not an AGPAT. In liver and brown adipose tissue from Agpat6-/- mice, NEM-sensitive GPAT specific activity was 65% lower than in wild-type mice, but AGPAT specific activity was unchanged. Overexpression of Agpat6 in Cos-7 cells increased NEM-sensitive GPAT activity but not AGPAT activity. Lipid intermediates (LPA, PA, DAG) initiated by GPAT4 lie in different cellular pools than those initiated by GPAT1.\",\n      \"method\": \"GPAT/AGPAT activity assays in tissues from knockout mice and overexpressing cells; [14C]oleate incorporation into lipid intermediates in Cos-7 cells\",\n      \"journal\": \"Journal of lipid research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — in vitro enzymatic assays with KO mouse tissues and overexpression, isotope labeling, two orthogonal methods, independently corroborated by PMID:18238778\",\n      \"pmids\": [\"18192653\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"AGPAT6 (GPAT4) localizes exclusively to the endoplasmic reticulum in mammalian cells. Agpat6-/- mice show defective lactation with dramatically reduced lipid droplets in mammary epithelial cells and milk depleted of diacylglycerols and triacylglycerols, establishing its essential role in milk fat production.\",\n      \"method\": \"Gene-trap knockout mice; histology of mammary glands; northern blot; lipid analysis of milk; subcellular localization by ER marker co-localization\",\n      \"journal\": \"Journal of lipid research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — KO mouse with defined cellular phenotype (lipid droplet loss, milk fat depletion), ER localization by direct imaging, replicated by subsequent studies\",\n      \"pmids\": [\"16449762\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"GPAT3 and GPAT4 are both phosphorylated by insulin at Ser and Thr residues, leading to increased GPAT activity that is sensitive to the PI3K inhibitor wortmannin, linking insulin signaling to microsomal GPAT activity. Knockdown of GPAT3 but not GPAT4 in 3T3-L1 adipocytes significantly decreased GPAT activity and inhibited lipid accumulation and adipogenic marker expression during differentiation.\",\n      \"method\": \"shRNA knockdown in 3T3-L1 adipocytes; overexpression in insect and mammalian cells; phosphorylation assays with insulin treatment and wortmannin inhibition; GPAT activity assays; lipid accumulation and gene expression analysis\",\n      \"journal\": \"Journal of lipid research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct phosphorylation assay and activity measurement, single lab, two orthogonal methods (activity assay + KD phenotype)\",\n      \"pmids\": [\"20181984\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"GPAT1, but not GPAT4, is required to incorporate de novo synthesized fatty acids into triacylglycerol and to divert them away from β-oxidation. In primary hepatocytes from Gpat4-/- mice, incorporation of de novo synthesized fatty acid into TAG was similar to wild-type, but Gpat1-/- hepatocytes showed doubled fatty acid oxidation. This establishes that GPAT1 and GPAT4 metabolize distinct fatty acid pools in liver.\",\n      \"method\": \"Primary hepatocytes from Gpat1-/-, Gpat4-/-, and control mice; de novo fatty acid synthesis labeling; exogenous fatty acid incorporation assays; acylcarnitine measurements in vivo (fasting/refeeding protocol)\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — KO mouse hepatocytes with multiple metabolic readouts, in vitro and in vivo corroboration, multiple orthogonal methods\",\n      \"pmids\": [\"23908354\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"GPAT4 limits oxidation of exogenous fatty acids in brown adipocytes. Gpat4-/- brown adipocytes incorporated 33% less fatty acid into triacylglycerol and 46% more into β-oxidation pathway, specifically through increased oxidation of exogenous (not de novo) fatty acids. GPAT4 comprises ~65% of total GPAT activity in brown adipose tissue.\",\n      \"method\": \"Gpat4-/- mice; metabolic rate measurements; neonatal BAT preadipocytes differentiated to adipocytes; fatty acid incorporation and oxidation assays; GPAT activity measurements; gene expression analysis\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — KO mouse with defined cellular phenotype, in vitro adipocyte assays, multiple metabolic readouts\",\n      \"pmids\": [\"25918168\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"CHP1 (calcineurin B homologous protein 1) binds and activates GPAT4. CHP1 must be N-myristoylated to activate GPAT4, forming a key molecular interface. Loss of CHP1 severely reduces fatty acid incorporation into glycerolipids in mammalian cells and invertebrates. Upon CHP1 loss, the peroxisomal enzyme GNPAT partially compensates for reduced ER lipid synthesis.\",\n      \"method\": \"CRISPR-based genetic screens; unbiased lipidomics; Co-IP/binding assays; CHP1 N-myristoylation mutants; fatty acid incorporation assays; invertebrate model validation\",\n      \"journal\": \"Molecular cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — CRISPR screen plus mechanistic follow-up with mutagenesis (N-myristoylation), lipidomics, cross-species validation, multiple orthogonal methods\",\n      \"pmids\": [\"30846317\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"GPAT4 synthesizes saturated lysophosphatidic acids (e.g., 1-stearoyl-LPA) at the contact site between omegasomes and the mitochondria-associated membrane (MAM). Accumulation of these saturated LPAs causes abnormal omegasome formation, leading to accumulation of autophagosomal precursor isolation membranes and inhibition of autophagic flux, contributing to vascular calcification and apoptosis in vascular smooth muscle cells.\",\n      \"method\": \"SCD-knockout VSMC model; lipid metabolite analysis; autophagic flux assays; omegasome imaging; GPAT4 functional studies in VSMCs\",\n      \"journal\": \"iScience\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — defined mechanistic pathway with lipid metabolite analysis and autophagy readouts, single lab, moderate mechanistic depth in abstract\",\n      \"pmids\": [\"32408172\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2022,\n      \"finding\": \"PPARγ acts as a transcription factor for AGPAT6 (GPAT4) via an RXRα binding site at -96 bp of the AGPAT6 promoter. Acetate stimulation increases the interaction between PPARγ and AGPAT6 promoter. AGPAT6 knockdown decreased acetate-induced mTORC1 signaling phosphorylation and intracellular TAG content; this was rescued by exogenous 16:0,18:1-phosphatidic acid, demonstrating that AGPAT6 activates mTORC1 by generating PA.\",\n      \"method\": \"Luciferase reporter assay with promoter deletions/mutations; siRNA knockdown; phosphatidic acid rescue experiment; western blot for mTORC1 signaling\",\n      \"journal\": \"The Journal of dairy research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — luciferase reporter with deletion mapping plus PA rescue experiment, single lab, two orthogonal methods\",\n      \"pmids\": [\"36398416\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"GPAT4 deficiency in endocardial cells provokes ER stress and enhances ER-mitochondria (ER-mito) communications, leading to mitochondrial DNA (mtDNA) escape. The escaped mtDNA activates the cGAS-STING pathway to stimulate type-I interferon response, which impairs heart development. Abolishment of cGAS-STING-type-I-interferon signaling rescued heart defects in Gpat4 deletion mice.\",\n      \"method\": \"Gpat4 global and tissue-specific knockout mice; ER stress markers; ER-mitochondria contact site imaging; mtDNA escape assay; cGAS-STING pathway analysis; genetic rescue with cGAS-STING pathway ablation\",\n      \"journal\": \"Nature communications\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — tissue-specific KO mice with defined molecular pathway (ER stress → mtDNA escape → cGAS-STING → IFN), genetic epistasis rescue, multiple orthogonal methods\",\n      \"pmids\": [\"40199910\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"CPT2 knockdown in colorectal cancer cells induces GPAT4-dependent accumulation of glycerophospholipids (primarily phosphatidylcholine and phosphatidylethanolamine), which promote autophagosome maturation and selective autophagy (lipophagy).\",\n      \"method\": \"CPT2 knockdown; metabolite analysis; transcriptomic analysis; in vitro and in vivo proliferation assays\",\n      \"journal\": \"Communications biology\",\n      \"confidence\": \"Low\",\n      \"confidence_rationale\": \"Tier 3 / Weak — GPAT4 role inferred from metabolite analysis after CPT2 KD, single lab, GPAT4 not directly manipulated in the abstract\",\n      \"pmids\": [\"41107458\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"GPAT4 diffuses in the ER membrane and translocates to lipid droplets (LDs) via seipin-containing ER-LD bridges (lateral transfer at membrane contact sites). Upon reaching the LD surface, GPAT4 becomes nano-confined, consistent with selective partitioning into nanoscale membrane domains that concentrate it at the LD surface.\",\n      \"method\": \"MINFLUX and HILO single-molecule tracking with machine learning; comparison with HSD17B13 and LiveDrop model cargo; seipin-containing bridge identification\",\n      \"journal\": \"bioRxiv\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Weak — single-molecule super-resolution imaging (MINFLUX) is high-tier method, but GPAT4 tracking is one of several cargoes examined and preprint is not peer-reviewed\",\n      \"pmids\": [\"bio_10.1101_2024.08.27.610018\"],\n      \"is_preprint\": true\n    },\n    {\n      \"year\": 2026,\n      \"finding\": \"FXR (farnesoid X receptor) transcriptionally inhibits GPAT4 expression. Dual-luciferase reporter assay confirmed FXR as a transcriptional repressor of GPAT4. FXR activation reduced lipid droplet accumulation by inhibiting GPAT4 in hepatic cell models.\",\n      \"method\": \"Dual-luciferase reporter assay; siRNA knockdown; western blot; HFD mouse model and oleic acid-induced HepG2 cell model\",\n      \"journal\": \"Chinese medicine\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — luciferase reporter directly mapping FXR-GPAT4 transcriptional regulation, siRNA knockdown with lipid phenotype, single lab\",\n      \"pmids\": [\"41530783\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"GPAT4 (originally misnamed AGPAT6) is an NEM-sensitive, ER-resident glycerol-3-phosphate acyltransferase that catalyzes the first committed step of de novo glycerolipid synthesis by acylating glycerol-3-phosphate to produce lysophosphatidic acid (LPA), using both saturated and unsaturated long-chain fatty acyl-CoAs as substrates; it is activated by the N-myristoylated adaptor protein CHP1, phosphorylated and activated downstream of insulin/PI3K signaling, traffics from the ER to lipid droplets via seipin-containing ER-LD bridges, and its generated phosphatidic acid activates mTORC1, while its absence in brown adipocytes increases fatty acid β-oxidation, in liver specifically channels de novo (but not exogenous) fatty acids away from oxidation, and in endocardial cells maintains ER homeostasis by preventing ER stress-induced mtDNA escape and cGAS-STING-mediated type-I interferon activation.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"GPAT4 (originally misnamed AGPAT6) is an N-ethylmaleimide-sensitive, endoplasmic reticulum-resident glycerol-3-phosphate acyltransferase that catalyzes the first committed step of de novo glycerolipid synthesis, acylating glycerol-3-phosphate with saturated or unsaturated long-chain acyl-CoAs to generate lysophosphatidic acid and, downstream, phosphatidic acid [#0, #1, #2]. Enzymatic activity requires the N-myristoylated adaptor CHP1, which binds and activates GPAT4 at the ER, and is further enhanced by insulin-stimulated Ser/Thr phosphorylation in a PI3K-dependent manner [#6, #3]. The lipid intermediates GPAT4 produces define a metabolic pool distinct from that of GPAT1: GPAT4 governs acylation of exogenous fatty acids in brown adipocytes, such that its loss diverts fatty acids from triacylglycerol storage into β-oxidation, whereas GPAT1 handles de novo synthesized fatty acids in liver [#5, #4]. The phosphatidic acid generated by GPAT4 acts as a signaling lipid that activates mTORC1 [#8]. GPAT4 transcription is positively controlled by PPARγ and repressed by FXR, coupling its expression to lipid-droplet accumulation in hepatic and secretory cells [#8, #12]. Beyond catalysis, GPAT4 maintains ER homeostasis: its deficiency in endocardial cells provokes ER stress, enhanced ER–mitochondria contact, mtDNA escape, and cGAS-STING-driven type-I interferon signaling that impairs heart development, a defect rescued by ablating cGAS-STING signaling [#9]. GPAT4 also traffics from the ER to lipid droplets through seipin-containing ER-LD bridges [#11].\",\n  \"teleology\": [\n    {\n      \"year\": 2006,\n      \"claim\": \"Before its enzymatic identity was known, knockout phenotyping established that this ER-localized protein is essential for milk fat production, pinpointing a physiological role in glycerolipid synthesis.\",\n      \"evidence\": \"Gene-trap knockout mice with mammary histology, milk lipid analysis, and ER marker co-localization\",\n      \"pmids\": [\"16449762\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not define the biochemical reaction catalyzed\", \"Mechanism of lipid-droplet loss in mammary epithelium not resolved\"]\n    },\n    {\n      \"year\": 2008,\n      \"claim\": \"Resolved the long-standing misannotation by demonstrating the enzyme is a GPAT, not an AGPAT, fixing the first committed step of de novo glycerolipid synthesis as its function.\",\n      \"evidence\": \"In vitro GPAT/AGPAT assays with purified protein and overexpression, isotope labeling/MS, NEM sensitivity, and KO mouse tissue activity in HEK293/Cos-7 systems\",\n      \"pmids\": [\"18238778\", \"18192653\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How GPAT4-initiated intermediates are channeled to distinct cellular pools not yet defined\", \"Regulatory inputs unknown\"]\n    },\n    {\n      \"year\": 2010,\n      \"claim\": \"Connected GPAT4 activity to hormonal control by showing insulin stimulates its phosphorylation and activity via PI3K.\",\n      \"evidence\": \"Phosphorylation assays with insulin/wortmannin and GPAT activity measurement in adipocytes and overexpression systems\",\n      \"pmids\": [\"20181984\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Specific kinase and phosphosites not identified\", \"GPAT4 knockdown alone did not reduce adipocyte GPAT activity, leaving its quantitative contribution to adipogenesis unclear\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Established functional non-redundancy between GPAT isoforms by showing GPAT4, unlike GPAT1, does not channel de novo fatty acids into TAG in liver.\",\n      \"evidence\": \"Primary hepatocytes from Gpat1-/- and Gpat4-/- mice with de novo and exogenous fatty acid labeling plus in vivo acylcarnitine measurement\",\n      \"pmids\": [\"23908354\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural basis for substrate-pool selectivity unknown\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Defined GPAT4's tissue-specific substrate preference by showing it limits oxidation of exogenous fatty acids in brown adipocytes, complementing the liver finding.\",\n      \"evidence\": \"Gpat4-/- brown adipocytes with fatty acid incorporation/oxidation assays and metabolic rate measurements\",\n      \"pmids\": [\"25918168\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How exogenous vs de novo fatty acids are physically segregated to GPAT4 not resolved\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Identified the activating partner of GPAT4, showing N-myristoylated CHP1 binds and is required to drive ER lipid synthesis.\",\n      \"evidence\": \"CRISPR screens, Co-IP, CHP1 N-myristoylation mutants, lipidomics, and invertebrate validation\",\n      \"pmids\": [\"30846317\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Structural detail of the CHP1-GPAT4 interface not solved\", \"How CHP1 binding alters catalysis mechanistically unclear\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Linked GPAT4-produced saturated LPAs at omegasome/MAM contact sites to autophagy regulation, extending its role beyond bulk lipid storage.\",\n      \"evidence\": \"SCD-knockout VSMC model with lipid metabolite analysis, omegasome imaging, and autophagic flux assays\",\n      \"pmids\": [\"32408172\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"GPAT4 not directly perturbed to confirm causality\", \"Single lab; effect on autophagy not validated in other cell types\"]\n    },\n    {\n      \"year\": 2022,\n      \"claim\": \"Defined transcriptional and signaling outputs by showing PPARγ drives GPAT4 expression and that its phosphatidic acid product activates mTORC1.\",\n      \"evidence\": \"Luciferase reporter promoter mapping, siRNA knockdown, and PA rescue with mTORC1 western blots\",\n      \"pmids\": [\"36398416\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct binding of GPAT4-derived PA to mTORC1 components not shown\", \"Single cell context\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Revealed a homeostatic role beyond metabolism by showing GPAT4 loss triggers ER stress, mtDNA escape, and cGAS-STING-driven interferon signaling that disrupts heart development.\",\n      \"evidence\": \"Gpat4 global and tissue-specific KO mice with ER stress markers, ER-mito contact imaging, mtDNA escape assays, and genetic cGAS-STING rescue\",\n      \"pmids\": [\"40199910\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"How loss of GPAT4 catalysis specifically alters ER membrane lipid composition to provoke stress not defined\", \"Whether this pathway operates in non-cardiac tissues unknown\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Implicated GPAT4-dependent glycerophospholipid accumulation in autophagosome maturation downstream of CPT2 loss in colorectal cancer.\",\n      \"evidence\": \"CPT2 knockdown with metabolite/transcriptomic analysis and proliferation assays\",\n      \"pmids\": [\"41107458\"],\n      \"confidence\": \"Low\",\n      \"gaps\": [\"GPAT4 not directly manipulated; role inferred from metabolite changes\", \"Causal contribution to autophagy not established\"]\n    },\n    {\n      \"year\": 2026,\n      \"claim\": \"Added a second transcriptional regulator by showing FXR represses GPAT4 to limit hepatic lipid-droplet accumulation.\",\n      \"evidence\": \"Dual-luciferase reporter, siRNA knockdown, and HFD mouse/HepG2 lipid phenotyping\",\n      \"pmids\": [\"41530783\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct FXR binding element on the GPAT4 promoter not mapped\", \"Single lab\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The structural basis of GPAT4 catalysis and its activation by CHP1, and the mechanism by which it selectively partitions distinct fatty acid pools across tissues, remain unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"High\",\n      \"gaps\": [\"No high-resolution structure of GPAT4 or the CHP1-GPAT4 complex\", \"Molecular basis for de novo vs exogenous fatty acid channeling unknown\", \"Direct mechanism coupling GPAT4 activity to ER membrane homeostasis undefined\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0016740\", \"supporting_discovery_ids\": [0, 1, 6]},\n      {\"term_id\": \"GO:0016746\", \"supporting_discovery_ids\": [0]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005783\", \"supporting_discovery_ids\": [2, 11]},\n      {\"term_id\": \"GO:0005811\", \"supporting_discovery_ids\": [11]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"GO:0008654\", \"supporting_discovery_ids\": [0, 1]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\n      \"CHP1\"\n    ],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":5,"faith_total":6,"faith_pct":83.33333333333333}}