BAAT

Existing Annotations Review

GO Term	Evidence	Action	Reason
GO:0005777 peroxisome	IBA GO_REF:0000033	ACCEPT	Summary: Phylogenetic (IBA) inference that BAAT is active in the peroxisome. This is consistent with the experimentally-demonstrated peroxisomal localization of endogenous human and rat BAAT in hepatocytes. Reason: Peroxisomal localization is directly supported experimentally in this gene (PMID:17256745), so the IBA is well grounded. Supporting Evidence: PMID:17256745 Endogenous hBAAT and rBaat were found to specifically localize to peroxisomes in human and rat hepatocytes, respectively.
GO:0016747 acyltransferase activity, transferring groups other than amino-acyl groups	IBA GO_REF:0000033	MODIFY	Summary: IBA acyltransferase activity. This is a correct but general parent of the specific bile acid-CoA:amino acid N-acyltransferase (glycine N-choloyltransferase) activity of BAAT. Reason: The essence is correct but the term is too general. The specific, experimentally established molecular function is glycine N-choloyltransferase activity (GO:0047963). Propagation Review Root cause: TERM SCOPING PROBLEM Proposed replacements: glycine N-choloyltransferase activity Supporting Evidence: PMID:8034703 These data demonstrate that a single cDNA is present in human liver which codes for a protein capable of catalyzing the conjugation of cholic acid with both glycine and taurine.
GO:0008206 bile acid metabolic process	IBA GO_REF:0000033	ACCEPT	Summary: IBA involvement in bile acid metabolic process. BAAT catalyzes the terminal conjugation step of bile-acid metabolism, so this broad process term is correct. Reason: Well supported; BAAT is the bile-acid-conjugating enzyme. This is a correct (if broad) process term; the more specific children (bile acid biosynthetic process, bile acid conjugation) are also annotated. Supporting Evidence: PMID:12810727 Bile acid-CoA:amino acid N-acyltransferase (BACAT) catalyzes the conjugation of bile acids to glycine and taurine for excretion into bile.
GO:0006631 fatty acid metabolic process	IBA GO_REF:0000033	KEEP AS NON CORE	Summary: IBA involvement in fatty acid metabolic process, reflecting the acyl-CoA thioesterase/fatty-acyl-CoA hydrolase side activity of the BAAT/type-I acyl-CoA thioesterase family. In vitro BAAT hydrolyzes long/very-long-chain acyl-CoAs and conjugates fatty acids to glycine, but a physiological fatty-acid-metabolism role is hypothesized rather than established. Reason: A defensible family-level inference supported by in vitro activity, but not the core physiological function of BAAT (which is bile-acid conjugation). Retain as non-core. Supporting Evidence: PMID:12810727 We show here that recombinant hBACAT also can hydrolyze long- and very long-chain saturated acyl-CoAs (mainly C16:0-C26:0) and by mass spectrometry verified that hBACAT also conjugates fatty acids to glycine.
GO:0006637 acyl-CoA metabolic process	IBA GO_REF:0000033	ACCEPT	Summary: IBA involvement in acyl-CoA metabolic process. BAAT acts on acyl-CoA thioesters (bile-acyl-CoAs and, in vitro, fatty-acyl-CoAs), consuming/hydrolyzing the CoA thioester, so this process term is appropriate. Reason: Correct process-level term; BAAT metabolizes acyl-CoA substrates (choloyl-CoA and other acyl-CoAs). Supporting Evidence: PMID:12239217 substantially increased the bile acid-CoA thioesterase activity compared with wild type
GO:0047617 fatty acyl-CoA hydrolase activity	IBA GO_REF:0000033	KEEP AS NON CORE	Summary: IBA fatty acyl-CoA hydrolase activity, reflecting the family-level acyl-CoA thioesterase activity. BAAT hydrolyzes acyl-CoA thioesters (choloyl-CoA and, in vitro, long/very-long-chain fatty-acyl-CoAs). Reason: Correct at the family level and supported by in vitro data, but a secondary activity relative to the core bile-acid N-acyltransferase function. Supporting Evidence: PMID:12810727 We show here that recombinant hBACAT also can hydrolyze long- and very long-chain saturated acyl-CoAs (mainly C16:0-C26:0)
GO:0005777 peroxisome	IEA GO_REF:0000120	ACCEPT	Summary: Electronic (multi-method) peroxisome localization. Consistent with the experimental demonstration of endogenous peroxisomal BAAT in hepatocytes. Reason: Corroborated by IDA (PMID:17256745) and IBA/ISS evidence for peroxisomal location. Supporting Evidence: PMID:17256745 hBAAT and rBaat are peroxisomal enzymes present in undetectable amounts in the cytosol.
GO:0005829 cytosol	IEA GO_REF:0000120	ACCEPT	Summary: Electronic cytosol localization. BAAT has a cell-type-dependent cytosolic pool (mainly cytosolic in fibroblasts and in historical liver subcellular fractionation). Reason: Supported by IDA evidence for cytosolic localization (HPA; PMID:12810727; PMID:8034703). Supporting Evidence: PMID:12810727 localization experiments in human skin fibroblasts showed that the hBACAT enzyme is mainly cytosolic.
GO:0006629 lipid metabolic process	IEA GO_REF:0000117	KEEP AS NON CORE	Summary: ARBA electronic annotation to the very broad "lipid metabolic process". Bile acids and fatty acids are lipids, so this is a correct but high-level ancestor term. Reason: Too general to be informative and not the core function; correct as a broad ancestor of the bile-acid/fatty-acyl-CoA activities. Retain as non-core. Supporting Evidence: file:human/BAAT/BAAT-uniprot.txt Fatty acid metabolism; Hydrolase; Lipid metabolism; Peroxisome;
GO:0006637 acyl-CoA metabolic process	IEA GO_REF:0000120	ACCEPT	Summary: Electronic acyl-CoA metabolic process annotation (duplicate of the IBA acyl-CoA metabolic process). Correct; BAAT acts on acyl-CoA thioester substrates. Reason: Correct process term; BAAT consumes/hydrolyzes acyl-CoA thioesters. Supporting Evidence: PMID:12810727 recombinant hBACAT also can hydrolyze long- and very long-chain saturated acyl-CoAs (mainly C16:0-C26:0)
GO:0016289 acyl-CoA hydrolase activity	IEA GO_REF:0000116	ACCEPT	Summary: RHEA-mapped electronic acyl-CoA hydrolase activity. BAAT has an experimentally demonstrated acyl-CoA (bile-acyl-CoA) thioesterase/hydrolase activity, so this parent term is correct. Reason: Correct; the bile-acid-CoA thioesterase (choloyl-CoA hydrolase) activity is experimentally established (PMID:12239217, PMID:12810727), and additional acyl-CoA hydrolase activity was shown in vitro. This is a secondary (non-core) activity but correctly captured. Supporting Evidence: file:human/BAAT/BAAT-uniprot.txt May also act as an acyl-CoA thioesterase that
GO:0016790 thiolester hydrolase activity	IEA GO_REF:0000002	ACCEPT	Summary: InterPro-based electronic thiolester hydrolase activity. This is a broad parent of the acyl-CoA/choloyl-CoA thioesterase activity of BAAT and reflects the enzyme's membership in the C/M/P thioester hydrolase family. Reason: Correct broad hydrolase term consistent with the demonstrated thioesterase activity; the more specific children (choloyl-CoA hydrolase, acyl-CoA hydrolase) are also annotated. Supporting Evidence: file:human/BAAT/BAAT-uniprot.txt Belongs to the C/M/P thioester hydrolase family.
GO:0032787 monocarboxylic acid metabolic process	IEA GO_REF:0000117	KEEP AS NON CORE	Summary: ARBA electronic annotation to monocarboxylic acid metabolic process. Bile acids and fatty acids are monocarboxylic acids produced/handled by BAAT, so this broad process term is correct but uninformative. Reason: Correct broad ancestor term; not the core function. Retain as non-core. Supporting Evidence: PMID:12810727 recombinant hBACAT also can hydrolyze long- and very long-chain saturated acyl-CoAs (mainly C16:0-C26:0) and by mass spectrometry verified that hBACAT also conjugates fatty acids to glycine
GO:0033882 choloyl-CoA hydrolase activity	IEA GO_REF:0000120	ACCEPT	Summary: Electronic choloyl-CoA hydrolase activity (EC 3.1.2.27). This is the specific bile-acyl-CoA thioesterase activity of BAAT and is experimentally established. Reason: Directly supported by experimental data (PMID:12239217, PMID:12810727, PMID:8034703 / UniProt EC 3.1.2.27). Secondary but genuine activity. Supporting Evidence: PMID:12239217 substantially increased the bile acid-CoA thioesterase activity compared with wild type
GO:0047617 fatty acyl-CoA hydrolase activity	IEA GO_REF:0000117	KEEP AS NON CORE	Summary: ARBA electronic fatty acyl-CoA hydrolase activity (duplicate of the IBA/IDA fatty-acyl-CoA hydrolase annotations). BAAT hydrolyzes fatty-acyl-CoAs in vitro. Reason: Supported by in vitro data but a secondary activity relative to bile-acid conjugation. Supporting Evidence: PMID:12810727 recombinant hBACAT also can hydrolyze long- and very long-chain saturated acyl-CoAs (mainly C16:0-C26:0)
GO:0047961 glycine N-acyltransferase activity	IEA GO_REF:0000116	ACCEPT	Summary: RHEA-mapped glycine N-acyltransferase activity, reflecting the demonstrated conjugation of fatty acids (and bile acids) to glycine. BAAT conjugates the glycine amino group to acyl-CoA substrates. Reason: BAAT transfers acyl groups to glycine (glycine N-choloyltransferase for bile acids; in vitro also fatty acids). This is a correct sibling/parent-level N-acyltransferase term; the bile-acid-specific child (glycine N-choloyltransferase, GO:0047963) is the core function. Supporting Evidence: PMID:12810727 hBACAT also conjugates fatty acids to glycine
GO:0047963 glycine N-choloyltransferase activity	IEA GO_REF:0000120	ACCEPT	Summary: Electronic glycine N-choloyltransferase activity (EC 2.3.1.65) - the defining molecular function of BAAT. Corroborates the experimental (EXP/IDA) annotations of the same term. Reason: Core molecular function, experimentally established; the electronic annotation is correct. Supporting Evidence: PMID:2037576 a single monomeric enzyme is responsible for the conjugation of bile acids with glycine or taurine in human liver.
GO:0052815 medium-chain fatty acyl-CoA hydrolase activity	IEA GO_REF:0000116	MARK AS OVER ANNOTATED	Summary: RHEA-mapped medium-chain fatty acyl-CoA hydrolase activity. BAAT hydrolyzes acyl-CoAs in vitro; medium-chain specificity is a narrow electronic inference from Rhea reactions. Reason: The in vitro acyl-CoA hydrolase activity was reported mainly for long- and very-long-chain (C16-C26) acyl-CoAs (PMID:12810727); the medium-chain-specific claim is a fine-grained RHEA-derived electronic inference and likely an over-annotation of chain-length specificity. The general acyl-CoA hydrolase activity is retained via GO:0016289. Supporting Evidence: PMID:12810727 recombinant hBACAT also can hydrolyze long- and very long-chain saturated acyl-CoAs (mainly C16:0-C26:0)
GO:0052816 long-chain fatty acyl-CoA hydrolase activity	IEA GO_REF:0000116	KEEP AS NON CORE	Summary: RHEA-mapped long-chain fatty acyl-CoA hydrolase activity, consistent with the in vitro hydrolysis of long-chain (C16-C18) acyl-CoAs by recombinant BAAT. Reason: Supported by in vitro data (PMID:12810727) but a secondary in-vitro activity, not the core physiological function. Supporting Evidence: PMID:12810727 recombinant hBACAT also can hydrolyze long- and very long-chain saturated acyl-CoAs (mainly C16:0-C26:0)
GO:0052817 very long-chain fatty acyl-CoA hydrolase activity	IEA GO_REF:0000116	KEEP AS NON CORE	Summary: RHEA-mapped very-long-chain fatty acyl-CoA hydrolase activity, consistent with the in vitro hydrolysis of very-long-chain (up to C26) acyl-CoAs by recombinant BAAT. Reason: Supported by in vitro data (PMID:12810727) but a secondary in-vitro activity, not the core physiological function. Supporting Evidence: PMID:12810727 recombinant hBACAT also can hydrolyze long- and very long-chain saturated acyl-CoAs (mainly C16:0-C26:0)
GO:0005515 protein binding	IPI PMID:25416956 A proteome-scale map of the human interactome network.	MARK AS OVER ANNOTATED	Summary: Bare "protein binding" from a systematic high-throughput binary interactome screen (interaction with GOLGA8DP). Uninformative regarding BAAT's molecular function. Reason: Per curation guidance, "protein binding" is uninformative and this high-throughput Y2H interaction has no BAAT-specific functional follow-up; a biologically meaningful interaction for an enzyme is not established. Marked as over-annotated rather than removed. Supporting Evidence: PMID:25416956 a systematic map of ?14,000 high-quality human binary protein-protein interactions.
GO:0005515 protein binding	IPI PMID:32814053 Interactome Mapping Provides a Network of Neurodegenerative ...	MARK AS OVER ANNOTATED	Summary: Bare "protein binding" from a neurodegenerative-disease-focused Y2H interactome screen (multiple partners). Uninformative regarding BAAT's molecular function. Reason: Per curation guidance, "protein binding" is uninformative; these are high-throughput interactome hits without BAAT-specific functional characterization. Marked as over-annotated rather than removed. Supporting Evidence: PMID:32814053 generated by systematic yeast two-hybrid interaction screening of
GO:0001889 liver development	IEA GO_REF:0000107	MARK AS OVER ANNOTATED	Summary: Electronic annotation transferred from the rat ortholog (Ensembl Compara) to "liver development". BAAT is a liver-enriched metabolic enzyme, but there is no evidence that it participates in the developmental process of the liver. Reason: Automatic ortholog-based transfer of a developmental process term. BAAT's role is bile-acid conjugation in hepatocytes, not a molecular contribution to liver development; likely reflects expression/context rather than function. Supporting Evidence: PMID:12810727 Tissue expression studies showed strong expression of BACAT in liver, gallbladder, and the proximal and distal intestine.
GO:0002152 bile acid conjugation	IEA GO_REF:0000107	ACCEPT	Summary: Electronic (Ensembl Compara ortholog-transfer) annotation to bile acid conjugation - the core biological process of BAAT. Duplicate of the experimental IDA annotations of the same term. Reason: Core process, experimentally established; the electronic annotation is correct. Supporting Evidence: PMID:12810727 catalyzes the conjugation of bile acids to glycine and taurine for excretion into bile.
GO:0031100 animal organ regeneration	IEA GO_REF:0000107	MARK AS OVER ANNOTATED	Summary: Electronic annotation transferred from the rat ortholog to "animal organ regeneration". This likely reflects differential BAAT expression during liver regeneration in rat rather than a molecular function of the enzyme in regeneration. Reason: Automatic ortholog-based transfer; no evidence that BAAT's catalytic activity contributes mechanistically to organ regeneration. Over-annotation of a context/expression observation. Supporting Evidence: PMID:12810727 Tissue expression studies showed strong expression of BACAT in liver, gallbladder, and the proximal and distal intestine.
GO:0016747 acyltransferase activity, transferring groups other than amino-acyl groups	IDA PMID:12239217 Conserved residues in the putative catalytic triad of human ...	MODIFY	Summary: IDA acyltransferase activity from the catalytic-triad mutagenesis study, which directly assayed hBAT N-acyltransferase activity. Correct but general. Reason: The specific molecular function established in this and other studies is glycine N-choloyltransferase (bile acid-CoA:amino acid N-acyltransferase) activity (GO:0047963); the general acyltransferase term should be replaced with the specific one. Proposed replacements: glycine N-choloyltransferase activity Supporting Evidence: PMID:12239217 an enzyme catalyzing the conjugation of bile acids with the amino acids glycine or taurine
GO:0006699 bile acid biosynthetic process	TAS Reactome:R-HSA-193368	ACCEPT	Summary: Reactome (TAS) annotation placing BAAT in bile acid biosynthesis. BAAT catalyzes the terminal conjugation step of bile-acid synthesis, so this is a core biosynthetic-process annotation. Reason: Core process; conjugation is the final step of bile-acid biosynthesis. Also supported by experimental IDA (PMID:8034703, PMID:12810727). Supporting Evidence: PMID:12810727 catalyzes the conjugation of bile acids to glycine and taurine for excretion into bile.
GO:0008206 bile acid metabolic process	TAS Reactome:R-HSA-159431	ACCEPT	Summary: Reactome (TAS) annotation to bile acid metabolic process (duplicate of the IBA). Correct broad process term for the bile-acid-conjugating enzyme. Reason: Correct broad process; the specific children (biosynthesis, conjugation) are also annotated. Supporting Evidence: PMID:12810727 catalyzes the conjugation of bile acids to glycine and taurine for excretion into bile.
GO:0005829 cytosol	IDA GO_REF:0000052	ACCEPT	Summary: HPA immunofluorescence (IDA) cytosol localization. Consistent with the cell-type-dependent cytosolic pool of BAAT reported in the literature. Reason: Supported experimentally; BAAT has a cytosolic pool (mainly cytosolic in fibroblasts and historically in liver soluble fractions). Supporting Evidence: PMID:12810727 localization experiments in human skin fibroblasts showed that the hBACAT enzyme is mainly cytosolic.
GO:0005777 peroxisome	ISS GO_REF:0000024	ACCEPT	Summary: ISS peroxisome localization by sequence-similarity transfer from the rat ortholog (Q63276). Consistent with experimental peroxisomal localization of human BAAT. Reason: Corroborated by direct experimental evidence in human hepatocytes (PMID:17256745). Supporting Evidence: PMID:17256745 Endogenous hBAAT and rBaat were found to specifically localize to peroxisomes in human and rat hepatocytes, respectively.
GO:0033882 choloyl-CoA hydrolase activity	EXP PMID:12239217 Conserved residues in the putative catalytic triad of human ...	ACCEPT	Summary: Experimental choloyl-CoA (bile acid-CoA) thioesterase/hydrolase activity. The Cys-235-Ser mutant showed substantially increased thioesterase activity, directly demonstrating this activity for hBAT. Reason: Directly experimentally established secondary activity of BAAT (EC 3.1.2.27). Kept as a genuine (secondary) molecular function. Supporting Evidence: PMID:12239217 substantially increased the bile acid-CoA thioesterase activity compared with wild type
GO:0033882 choloyl-CoA hydrolase activity	EXP PMID:12810727 The human bile acid-CoA:amino acid N-acyltransferase functio...	ACCEPT	Summary: Experimental choloyl-CoA/acyl-CoA thioesterase activity from recombinant hBACAT (which hydrolyzes long/very-long-chain acyl-CoAs; the family is a type-I acyl-CoA thioesterase). Reason: Directly experimentally established secondary thioesterase activity. Supporting Evidence: PMID:12810727 identifying BACAT as a member of the type I acyl-CoA thioesterase gene family.
GO:0033882 choloyl-CoA hydrolase activity	EXP PMID:8034703 Glycine and taurine conjugation of bile acids by a single en...	ACCEPT	Summary: Experimental bile acid-CoA thioesterase (choloyl-CoA hydrolase) activity of purified/cloned hBAT. UniProt attributes EC 3.1.2.27 to this reference among others. Reason: Secondary thioesterase activity of BAAT, experimentally supported (UniProt EC 3.1.2.27, ECO:0000269\|PubMed:8034703). Supporting Evidence: file:human/BAAT/BAAT-uniprot.txt May also act as an acyl-CoA thioesterase that
GO:0047963 glycine N-choloyltransferase activity	EXP PMID:12239217 Conserved residues in the putative catalytic triad of human ...	ACCEPT	Summary: Experimental glycine N-choloyltransferase (bile acid-CoA:amino acid N-acyltransferase) activity established via catalytic-triad mutagenesis (Cys-235/Asp-328/His-362) of hBAT. This is the core molecular function of BAAT. Reason: Core molecular function, directly experimentally established. Catalytic-triad substitutions abolish or reduce N-acyltransferase activity. Supporting Evidence: PMID:12239217 data from this study support the existence of an essential catalytic triad within hBAT consisting of Cys-235, His-362, and Asp-328
GO:0016746 acyltransferase activity	TAS Reactome:R-HSA-159431	MODIFY	Summary: Reactome (TAS) general acyltransferase activity. Correct but a general parent of the specific bile acid-CoA:amino acid N-acyltransferase function. Reason: Too general; the specific molecular function is glycine N-choloyltransferase activity (GO:0047963). Proposed replacements: glycine N-choloyltransferase activity Supporting Evidence: PMID:2037576 a single monomeric enzyme is responsible for the conjugation of bile acids with glycine or taurine in human liver.
GO:0016746 acyltransferase activity	TAS Reactome:R-HSA-192312	MODIFY	Summary: Reactome (TAS) general acyltransferase activity (choloyl-CoA + glycine/taurine reaction). Correct but general. Reason: Too general; the specific function is glycine N-choloyltransferase activity (GO:0047963). Proposed replacements: glycine N-choloyltransferase activity Supporting Evidence: PMID:8034703 capable of catalyzing the conjugation of cholic acid with both glycine and taurine.
GO:0016746 acyltransferase activity	TAS Reactome:R-HSA-193491	MODIFY	Summary: Reactome (TAS) general acyltransferase activity (chenodeoxycholoyl-CoA + glycine/taurine reaction). Correct but general. Reason: Too general; the specific function is glycine N-choloyltransferase activity (GO:0047963). Proposed replacements: glycine N-choloyltransferase activity Supporting Evidence: PMID:8034703 capable of catalyzing the conjugation of cholic acid with both glycine and taurine.
GO:0002152 bile acid conjugation	IDA PMID:2037576 Purification and characterization of bile acid-CoA:amino aci...	ACCEPT	Summary: IDA bile acid conjugation from purification/characterization of the human liver enzyme, which conjugates bile acids with glycine or taurine. Core biological process of BAAT. Reason: Core process, directly experimentally established. Supporting Evidence: PMID:2037576 a single monomeric enzyme is responsible for the conjugation of bile acids with glycine or taurine in human liver.
GO:0047963 glycine N-choloyltransferase activity	IDA PMID:2037576 Purification and characterization of bile acid-CoA:amino aci...	ACCEPT	Summary: IDA glycine N-choloyltransferase activity from the purified human liver enzyme. Core molecular function of BAAT. Reason: Core molecular function, directly experimentally established. Supporting Evidence: PMID:2037576 The purified enzyme utilized glycine, taurine, and 2-fluoro-beta-alanine
GO:0005782 peroxisomal matrix	TAS Reactome:R-HSA-192312	ACCEPT	Summary: Reactome (TAS) peroxisomal matrix localization. BAAT is a soluble matrix enzyme imported into peroxisomes (PTS-dependent), consistent with matrix (a child of peroxisome) location. Reason: Consistent with experimental peroxisomal localization (PMID:17256745) and PTS-dependent peroxisomal import; peroxisomal matrix is an appropriate specific compartment. Supporting Evidence: PMID:17256745 Endogenous hBAAT and rBaat were found to specifically localize to peroxisomes in human and rat hepatocytes, respectively.
GO:0005782 peroxisomal matrix	TAS Reactome:R-HSA-193491	ACCEPT	Summary: Reactome (TAS) peroxisomal matrix localization (chenodeoxycholoyl-CoA conjugation reaction). Consistent with BAAT being a matrix peroxisomal enzyme. Reason: Consistent with experimental peroxisomal localization and matrix import. Supporting Evidence: PMID:17256745 Endogenous hBAAT and rBaat were found to specifically localize to peroxisomes in human and rat hepatocytes, respectively.
GO:0005782 peroxisomal matrix	TAS Reactome:R-HSA-9033235	ACCEPT	Summary: Reactome (TAS) peroxisomal matrix localization (peroxisomal protein import). BAAT is a PTS-containing cargo imported into the peroxisomal matrix. Reason: Consistent with peroxisomal matrix import of BAAT. Supporting Evidence: PMID:17256745 hBAAT and rBaat are peroxisomal enzymes present in undetectable amounts in the cytosol.
GO:0005829 cytosol	TAS Reactome:R-HSA-159431	ACCEPT	Summary: Reactome (TAS) cytosol localization (bile acid conjugation reaction placed in the cytosol). Consistent with the cytosolic BAAT pool. Reason: Supported by IDA cytosolic localization; Reactome models bile-acid conjugation in the cytosol, and a cytosolic BAAT pool is documented. Supporting Evidence: PMID:12810727 the hBACAT enzyme is mainly cytosolic.
GO:0005829 cytosol	TAS Reactome:R-HSA-9033235	ACCEPT	Summary: Reactome (TAS) cytosol localization (peroxisomal import - cargo starts in the cytosol before translocation). Consistent with cytosolic BAAT prior to peroxisomal import. Reason: Consistent with the documented cytosolic pool of BAAT. Supporting Evidence: PMID:12810727 the hBACAT enzyme is mainly cytosolic.
GO:0005829 cytosol	TAS Reactome:R-HSA-9033236	ACCEPT	Summary: Reactome (TAS) cytosol localization (PEX5 docking of cargo). Consistent with cytosolic BAAT prior to peroxisomal import. Reason: Consistent with the documented cytosolic pool of BAAT. Supporting Evidence: PMID:12810727 the hBACAT enzyme is mainly cytosolic.
GO:0052815 medium-chain fatty acyl-CoA hydrolase activity	IDA PMID:12810727 The human bile acid-CoA:amino acid N-acyltransferase functio...	MARK AS OVER ANNOTATED	Summary: IDA medium-chain fatty acyl-CoA hydrolase activity. The reported in vitro acyl-CoA hydrolysis by recombinant BAAT was mainly for long- and very-long-chain (C16-C26) substrates. Reason: The study emphasized long/very-long-chain (C16-C26) acyl-CoA hydrolysis; a specific medium-chain hydrolase claim is at best a minor in-vitro activity and likely an over-annotation of chain-length specificity. The general acyl-CoA/choloyl-CoA hydrolase activity is retained. Supporting Evidence: PMID:12810727 recombinant hBACAT also can hydrolyze long- and very long-chain saturated acyl-CoAs (mainly C16:0-C26:0)
GO:0052816 long-chain fatty acyl-CoA hydrolase activity	IDA PMID:12810727 The human bile acid-CoA:amino acid N-acyltransferase functio...	KEEP AS NON CORE	Summary: IDA long-chain fatty acyl-CoA hydrolase activity, directly supported by the in vitro hydrolysis of long-chain (C16-C18) acyl-CoAs by recombinant BAAT. Reason: Genuine in vitro activity but secondary to the core bile-acid N-acyltransferase function. Supporting Evidence: PMID:12810727 recombinant hBACAT also can hydrolyze long- and very long-chain saturated acyl-CoAs (mainly C16:0-C26:0)
GO:0052817 very long-chain fatty acyl-CoA hydrolase activity	IDA PMID:12810727 The human bile acid-CoA:amino acid N-acyltransferase functio...	KEEP AS NON CORE	Summary: IDA very-long-chain fatty acyl-CoA hydrolase activity, directly supported by the in vitro hydrolysis of very-long-chain (up to C26) acyl-CoAs by recombinant BAAT. Reason: Genuine in vitro activity but secondary to the core bile-acid N-acyltransferase function; may relate to a proposed role in regulating intracellular VLCFA levels. Supporting Evidence: PMID:12810727 important functions also in the regulation of intracellular levels of very long-chain fatty acids.
GO:0005777 peroxisome	IDA PMID:17256745 Human and rat bile acid-CoA:amino acid N-acyltransferase are...	ACCEPT	Summary: IDA peroxisome localization. Endogenous human BAAT localizes specifically to peroxisomes in hepatocytes by immunofluorescence and digitonin-permeabilization. Primary localization evidence. Reason: Direct experimental evidence for peroxisomal localization of endogenous human BAAT. This is the strongest localization annotation. Supporting Evidence: PMID:17256745 Endogenous hBAAT and rBaat were found to specifically localize to peroxisomes in human and rat hepatocytes, respectively.
GO:0005829 cytosol	IDA PMID:17256745 Human and rat bile acid-CoA:amino acid N-acyltransferase are...	ACCEPT	Summary: IDA cytosol localization from the same study - GFP-tagged hBAAT localized to the cytosol when expressed in fibroblasts, indicating a cell-type-dependent cytosolic pool. Reason: Supported experimentally; BAAT localization is cell-type-dependent, with cytosolic localization in fibroblasts (and a cytosolic pool documented in liver fractionation). Supporting Evidence: PMID:17256745 When expressed in fibroblasts, GFP-tagged hBAAT localized to the cytosol, confirming earlier observations.
GO:0005829 cytosol	IDA PMID:8034703 Glycine and taurine conjugation of bile acids by a single en...	ACCEPT	Summary: IDA cytosol localization from the cloning/expression study (enzyme activity in the cytosol fraction of expressing cells; historically BAAT was recovered from the soluble/cytosolic liver fraction). Reason: Consistent with the documented cytosolic pool of BAAT. Supporting Evidence: PMID:8034703 cytosol of Escherichia coli XL1-Blue cells transfected with hBAT8 subcloned into PMID:2037576 purified 480-fold from the soluble fraction of homogenized frozen human
GO:0006544 glycine metabolic process	IDA PMID:8034703 Glycine and taurine conjugation of bile acids by a single en...	KEEP AS NON CORE	Summary: IDA involvement in glycine metabolic process. BAAT consumes glycine by conjugating it to bile acids (and, in vitro, fatty acids), so the enzyme participates in glycine utilization. Reason: BAAT uses glycine as a co-substrate, but its core function is bile-acid conjugation rather than glycine metabolism per se. Retain as a non-core (co-substrate-based) process annotation. Supporting Evidence: PMID:8034703 catalyzing the conjugation of cholic acid with both glycine and taurine.
GO:0006637 acyl-CoA metabolic process	IDA PMID:12810727 The human bile acid-CoA:amino acid N-acyltransferase functio...	ACCEPT	Summary: IDA involvement in acyl-CoA metabolic process. BAAT metabolizes acyl-CoA thioesters (bile-acyl-CoAs and, in vitro, fatty-acyl-CoAs) via its transferase and thioesterase activities. Reason: Correct process; BAAT acts directly on acyl-CoA thioester substrates. Supporting Evidence: PMID:12810727 recombinant hBACAT also can hydrolyze long- and very long-chain saturated acyl-CoAs (mainly C16:0-C26:0)
GO:0006699 bile acid biosynthetic process	IDA PMID:8034703 Glycine and taurine conjugation of bile acids by a single en...	ACCEPT	Summary: IDA involvement in bile acid biosynthetic process. Conjugation catalyzed by BAAT is the terminal step of bile-acid synthesis in the liver. Core biosynthetic-process annotation. Reason: Core process, directly experimentally established. Supporting Evidence: PMID:8034703 capable of catalyzing the conjugation of cholic acid with both glycine and taurine.
GO:0019530 taurine metabolic process	IDA PMID:8034703 Glycine and taurine conjugation of bile acids by a single en...	KEEP AS NON CORE	Summary: IDA involvement in taurine metabolic process. BAAT consumes taurine by conjugating it to bile acids, participating in taurine utilization. Reason: BAAT uses taurine as a co-substrate; its core function is bile-acid conjugation rather than taurine metabolism per se. Retain as a non-core (co-substrate-based) process annotation. Supporting Evidence: PMID:8034703 catalyzing the conjugation of cholic acid with both glycine and taurine.
GO:0047963 glycine N-choloyltransferase activity	IDA PMID:12810727 The human bile acid-CoA:amino acid N-acyltransferase functio...	ACCEPT	Summary: IDA glycine N-choloyltransferase (bile acid-CoA:amino acid N-acyltransferase) activity from the recombinant-enzyme study. Core molecular function of BAAT. Reason: Core molecular function, directly experimentally established. Supporting Evidence: PMID:12810727 catalyzes the conjugation of bile acids to glycine and taurine for excretion into bile.
GO:0047963 glycine N-choloyltransferase activity	IDA PMID:8034703 Glycine and taurine conjugation of bile acids by a single en...	ACCEPT	Summary: IDA glycine N-choloyltransferase activity from the cloning/expression study, which showed a single hBAT enzyme conjugates cholic acid with both glycine and taurine. Core molecular function. Reason: Core molecular function, directly experimentally established. Supporting Evidence: PMID:8034703 capable of catalyzing the conjugation of cholic acid with both glycine and taurine.
GO:0002152 bile acid conjugation	IDA PMID:12810727 The human bile acid-CoA:amino acid N-acyltransferase functio...	ACCEPT	Summary: IDA bile acid conjugation from the recombinant-enzyme study. Core biological process of BAAT. Reason: Core process, directly experimentally established. Supporting Evidence: PMID:12810727 catalyzes the conjugation of bile acids to glycine and taurine for excretion into bile.
GO:0002152 bile acid conjugation	IDA PMID:8034703 Glycine and taurine conjugation of bile acids by a single en...	ACCEPT	Summary: IDA bile acid conjugation from the cloning/expression study. Core biological process of BAAT. Reason: Core process, directly experimentally established. Supporting Evidence: PMID:8034703 capable of catalyzing the conjugation of cholic acid with both glycine and taurine.
GO:0005829 cytosol	IDA PMID:12810727 The human bile acid-CoA:amino acid N-acyltransferase functio...	ACCEPT	Summary: IDA cytosol localization from GFP-localization in human skin fibroblasts, where hBACAT was mainly cytosolic. Consistent with the cell-type-dependent cytosolic pool. Reason: Supported experimentally; BAAT is mainly cytosolic in fibroblasts. Supporting Evidence: PMID:12810727 localization experiments in human skin fibroblasts showed that the hBACAT enzyme is mainly cytosolic.
GO:0006699 bile acid biosynthetic process	IDA PMID:12810727 The human bile acid-CoA:amino acid N-acyltransferase functio...	ACCEPT	Summary: IDA involvement in bile acid biosynthetic process from the recombinant-enzyme study. Conjugation is the terminal step of bile-acid synthesis. Core biosynthetic-process annotation. Reason: Core process, directly experimentally established. Supporting Evidence: PMID:12810727 catalyzes the conjugation of bile acids to glycine and taurine for excretion into bile.

Gene Description

Existing Annotations Review

Core Functions

References

📚 Additional Documentation

Notes

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