Details for: BAAT

Gene ID: 570

Gene Type:  Protein-coding  - A gene that serves as a template for producing a messenger RNA (mRNA) molecule, which is then translated into a functional protein.

Symbol: BAAT

Ensembl ID: ENSG00000136881

Description: bile acid-CoA:amino acid N-acyltransferase

Cell Significance Landscape

Associated with

Significant Cells

Cell Significance Index (CSI) scores for the chosen context(s)

  • hepatocyte CL0000182
    CSI 16.89
    rCSI 30.23%
    PRS 99.06
  • centrilobular region hepatocyte CL0019029
    CSI 16.24
    rCSI 42.38%
    PRS 98.89
  • midzonal region hepatocyte CL0019028
    CSI 15.9
    rCSI 37.31%
    PRS 99.12
  • hepatic stellate cell CL0000632
    CSI 9.29
    rCSI 34.79%
    PRS 99.51
  • periportal region hepatocyte CL0019026
    CSI 8.7
    rCSI 33.82%
    PRS 99.04
  • pvalb GABAergic cortical interneuron CL4023018
    CSI 7.72
    rCSI 9.6%
    PRS 98.51
  • Kupffer cell CL0000091
    CSI 7.51
    rCSI 17.18%
    PRS 99.66
  • endothelial cell of periportal hepatic sinusoid CL0019021
    CSI 7.51
    rCSI 34.47%
    PRS 99.79
  • epithelial cell CL0000066
    CSI 6.74
    rCSI 10.36%
    PRS 98.09
  • pancreatic ductal cell CL0002079
    CSI 4.78
    rCSI 9.3%
    PRS 99.54
  • L2/3-6 intratelencephalic projecting glutamatergic neuron CL4023040
    CSI 4.76
    rCSI 11.56%
    PRS 98.17
  • intrahepatic cholangiocyte CL0002538
    CSI 4.41
    rCSI 10.57%
    PRS 99.62
  • endothelial cell of pericentral hepatic sinusoid CL0019022
    CSI 4.22
    rCSI 13%
    PRS 99.79
  • near-projecting glutamatergic cortical neuron CL4023012
    CSI 1.98
    rCSI 7.47%
    PRS 98.41
  • L5 extratelencephalic projecting glutamatergic cortical neuron CL4023041
    CSI 1.87
    rCSI 6.73%
    PRS 98.45

Cell ID: Standard Cell Ontology term used for mapping and comparing cells across experiments. Ensures consistency in analyzing cellular functions across tissues.
Fold Change: Represents the ratio of the current Cell Significance Index to the Cell Significance Index Threshold, indicating how much the gene expression has changed compared to a baseline.
Cell Significance Index: Reflects how strongly a gene is expressed in this specific cell.

Cell ID: Standard Cell Ontology term used for mapping and comparing cells across experiments. Ensures consistency in analyzing cellular functions across tissues.
Fold Change: Represents the ratio of the current Cell Significance Index to the Cell Significance Index Threshold, indicating how much the gene expression has changed compared to a baseline.
Cell Significance Index: Reflects how strongly a gene is expressed in this cell type. Calculated using techniques like effect size estimation and bootstrapping for reliability.

Cell ID: Standard Cell Ontology term used for mapping and comparing cells across experiments. Ensures consistency in analyzing cellular functions across tissues.
Fold Change: Represents the ratio of the current Cell Significance Index to the Cell Significance Index Threshold, indicating how much the gene expression has changed compared to a baseline.
Cell Significance Index: Reflects how strongly a gene is expressed in this cell type. Calculated using techniques like effect size estimation and bootstrapping for reliability.
Network Configuration

Explore relationships of the current gene. Select an Interaction Source: 'ONTOLOGY' for shared pathways (GO/Reactome) or 'STRING' for protein-protein interactions. Further refine by selecting context genes and comparing Cell Significance Index (CSI) scores between baseline and target cell types and their specific contexts.

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Comma-separated if multiple.
Legend:
  • Query Gene
  • Node Color (Target Cell CSI, relative to current network):
    • Very High
    • High
    • Medium
    • Low
    • Very Low
    • CSI N/A
  • Node Size: Proportional to Target Cell CSI magnitude
  • STRING PPI Edge
  • Shared Pathway Edge (ONTOLOGY)

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Other Information

This section provides additional information about the gene, including a description generated by an AI language model and details about associated proteins.

## Summary Bile acid-CoA:amino acid N-acyltransferase, encoded by the [BAAT](/details-gene/570) gene, is a critical enzyme in hepatic metabolism. Its primary function is to catalyze the final step of bile acid synthesis, which involves the conjugation of bile acids with either glycine or taurine before their secretion into bile ([Link](https://doi.org/10.1016/s0021-9258(17)32178-6)). This process is essential for solubilizing bile acids and facilitating the digestion and absorption of dietary fats and fat-soluble vitamins. Expression data reveals that [BAAT](/details-gene/570) is overwhelmingly significant in liver cells, particularly [hepatocytes](/details-cell/CL0000182), consistent with its central role in bile acid metabolism. Clinically, loss-of-function mutations in [BAAT](/details-gene/570) are associated with familial hypercholanemia, a condition characterized by elevated levels of unconjugated bile acids, fat malabsorption, and deficiency of fat-soluble vitamins ([Link](https://doi.org/10.1053/j.gastro.2013.02.004), [Link](https://doi.org/10.1038/ng1147)). ## Cellular Roles and Expression Landscape The expression profile of [BAAT](/details-gene/570) firmly establishes its identity as a key gene in hepatic function. **Overall**, the gene shows the highest significance in [hepatocytes](/details-cell/CL0000182) (CSI: 16.89), with robust expression also noted across different hepatocyte zones, including [centrilobular region hepatocytes](/details-cell/CL0019029) (CSI: 16.24) and [midzonal region hepatocytes](/details-cell/CL0019028) (CSI: 15.90). This pattern underscores its fundamental role in the metabolic machinery of the liver parenchyma. Beyond hepatocytes, [BAAT](/details-gene/570) demonstrates notable significance in other liver-resident cells, such as [hepatic stellate cells](/details-cell/CL0000632) and [Kupffer cells](/details-cell/CL0000091), suggesting its activity contributes to the broader liver microenvironment. Interestingly, the data also indicate a lower but still significant expression in select non-hepatic cell types. These include [pancreatic ductal cells](/details-cell/CL0002079) and specific neuronal populations like [pvalb GABAergic cortical interneurons](/details-cell/CL4023018) and L2/3-6 intratelencephalic projecting glutamatergic neurons. This suggests that while [BAAT](/details-gene/570) is predominantly a hepatic enzyme, it may have secondary, specialized roles in other tissues. ## Pathways and Molecular Function The molecular functions and biological pathways associated with [BAAT](/details-gene/570) are highly consistent with its role as a core metabolic enzyme in the liver. Gene Ontology annotations highlight its function as an acyltransferase, specifically demonstrating `glycine n-choloyltransferase activity` ([GO:0047963](https://www.ebi.ac.uk/QuickGO/term/GO:0047963)) and `N-acyltransferase activity` ([GO:0016410](https://www.ebi.ac.uk/QuickGO/term/GO:0016410)). The enzyme is localized primarily to the `peroxisome` ([GO:0005777](https://www.ebi.ac.uk/QuickGO/term/GO:0005777)), a key site for lipid metabolism ([Link](https://doi.org/10.1074/jbc.m207463200)). From a process-level perspective, [BAAT](/details-gene/570) is a central player in `bile acid conjugation` ([GO:0002152](https://www.ebi.ac.uk/QuickGO/term/GO:0002152)) and the broader `bile acid metabolic process` ([GO:0008206](https://www.ebi.ac.uk/QuickGO/term/GO:0008206)). These functions are further detailed in the Reactome database, which places [BAAT](/details-gene/570) in the `Synthesis of bile acids and bile salts` pathway ([R-HSA-192105](https://reactome.org/content/detail/R-HSA-192105)) and the `Recycling of bile acids and salts` pathway ([R-HSA-159418](https://reactome.org/content/detail/R-HSA-159418)). Its involvement in `liver development` ([GO:0001889](https://www.ebi.ac.uk/QuickGO/term/GO:0001889)) further solidifies its foundational importance in establishing and maintaining the metabolic competence of the liver. ## Research Directions The well-defined role of [BAAT](/details-gene/570) in hepatic bile acid metabolism provides a strong foundation for further research, particularly concerning its potential involvement in metabolic diseases and its less-understood extra-hepatic functions. Based on the available data, several testable hypotheses can be proposed: 1. **Role in Metabolic Syndrome:** Dysregulation of [BAAT](/details-gene/570) expression or activity in [hepatocytes](/details-cell/CL0000182) may be a key factor in the pathophysiology of metabolic diseases such as non-alcoholic fatty liver disease (NAFLD) and cholestasis. Alterations in the bile acid pool composition due to suboptimal [BAAT](/details-gene/570) function could exacerbate lipotoxicity and inflammation in the liver. 2. **Neuromodulatory Function:** The consistent, albeit low-level, expression of [BAAT](/details-gene/570) in specific neuronal subtypes, such as [pvalb GABAergic cortical interneurons](/details-cell/CL4023018), suggests a novel function in the central nervous system. [BAAT](/details-gene/570) may be involved in conjugating specific fatty acids or steroid derivatives, thereby generating signaling molecules that modulate neuronal excitability or synaptic plasticity. To investigate the second, more novel hypothesis, a key experiment would be to delineate the function of [BAAT](/details-gene/570) in neurons. A compelling approach would be to generate a neuron-specific conditional knockout of `Baat` in mice using a Cre-Lox system (e.g., Pvalb-Cre mice). Subsequent analysis using mass spectrometry-based lipidomics on isolated cortical interneurons from knockout and wild-type animals could identify the specific substrates that accumulate in the absence of [BAAT](/details-gene/570). This could be complemented with electrophysiological recordings to determine if the loss of [BAAT](/details-gene/570) function alters the intrinsic firing properties or synaptic integration of these neurons. Therapeutically, [BAAT](/details-gene/570) is primarily relevant in the context of monogenic loss-of-function disorders. Therefore, the therapeutic strategy would focus on **activation** or **restoration** of function. For patients with inactivating mutations, liver-directed gene therapy to re-introduce a functional copy of the [BAAT](/details-gene/570) gene represents a promising long-term corrective strategy. Given that its inhibition would mimic a known disease state, developing inhibitors for [BAAT](/details-gene/570) is not a viable therapeutic avenue.

Genular Protein ID: 2155909131

Symbol: BAAT_HUMAN

Name: Choloyl-CoA hydrolase

UniProtKB Accession Codes:

Q14032 Q3B7W9 Q96L31

Database IDs:

AGR 1 AlphaFoldDB 1 Antibodypedia 1 BRENDA 1 Bgee 1 BioGRID 1 BioGRID-ORCS 1 BioMuta 1 CCDS 1 CTD 1 CarbonylDB 1 ChEBI 85 DMDM 1 DNASU 1 DisGeNET 1 DrugBank 2 EC 4 EMBL 6 ESTHER 1 Ensembl 4 ExpressionAtlas 1 GO 22 Gene3D 2 GeneCards 1 GeneTree 1 GeneWiki 1 GenomeRNAi 1 HGNC 1 HOGENOM 1 HPA 1 InParanoid 1 IntAct 1 InterPro 5 KEGG 1 MANE-Select 1 MEROPS 1 MIM 3 MINT 1 MalaCards 1 MassIVE 1 NCBI Taxonomy 1 OMA 1 OpenTargets 1 Orphanet 1 OrthoDB 1 PANTHER 2 PIR 1 PIRSF 1 PRO 1 PathwayCommons 1 PaxDb 1 PeptideAtlas 1 Pfam 2 PharmGKB 1 Pharos 1 PhosphoSitePlus 1 PhylomeDB 1 Proteomes 1 ProteomicsDB 1 RNAct 1 Reactome 3 RefSeq 2 Rhea 34 SABIO-RK 1 SMR 1 STRING 1 SUPFAM 1 SignaLink 1 SwissLipids 1 TreeFam 1 UCSC 1 VEuPathDB 1 eggNOG 1 iPTMnet 1 neXtProt 1

Citations:

PubMed ID: 8034703

Title: Glycine and taurine conjugation of bile acids by a single enzyme. Molecular cloning and expression of human liver bile acid CoA:amino acid N-acyltransferase.

PubMed ID: 8034703

DOI: 10.1016/s0021-9258(17)32178-6

PubMed ID: 15164053

Title: DNA sequence and analysis of human chromosome 9.

PubMed ID: 15164053

DOI: 10.1038/nature02465

PubMed ID: 15489334

Title: The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC).

PubMed ID: 15489334

DOI: 10.1101/gr.2596504

PubMed ID: 2037576

Title: Purification and characterization of bile acid-CoA:amino acid N-acyltransferase from human liver.

PubMed ID: 2037576

DOI: 10.1016/s0021-9258(18)99213-6

PubMed ID: 12239217

Title: Conserved residues in the putative catalytic triad of human bile acid Coenzyme A:amino acid N-acyltransferase.

PubMed ID: 12239217

DOI: 10.1074/jbc.m207463200

PubMed ID: 12810727

Title: The human bile acid-CoA:amino acid N-acyltransferase functions in the conjugation of fatty acids to glycine.

PubMed ID: 12810727

DOI: 10.1074/jbc.m300987200

PubMed ID: 23415802

Title: Genetic defects in bile acid conjugation cause fat-soluble vitamin deficiency.

PubMed ID: 23415802

DOI: 10.1053/j.gastro.2013.02.004

PubMed ID: 24275569

Title: An enzyme assisted RP-RPLC approach for in-depth analysis of human liver phosphoproteome.

PubMed ID: 24275569

DOI: 10.1016/j.jprot.2013.11.014

PubMed ID: 12704386

Title: Complex inheritance of familial hypercholanemia with associated mutations in TJP2 and BAAT.

PubMed ID: 12704386

DOI: 10.1038/ng1147

Sequence Information:

  • Length: 418
  • Mass: 46299
  • Checksum: 4B290BAEE97F23B3
  • Sequence:
    • MIQLTATPVS ALVDEPVHIR ATGLIPFQMV SFQASLEDEN GDMFYSQAHY RANEFGEVDL 
NHASSLGGDY MGVHPMGLFW SLKPEKLLTR LLKRDVMNRP FQVQVKLYDL ELIVNNKVAS 
APKASLTLER WYVAPGVTRI KVREGRLRGA LFLPPGEGLF PGVIDLFGGL GGLLEFRASL 
LASRGFASLA LAYHNYEDLP RKPEVTDLEY FEEAANFLLR HPKVFGSGVG VVSVCQGVQI 
GLSMAIYLKQ VTATVLINGT NFPFGIPQVY HGQIHQPLPH SAQLISTNAL GLLELYRTFE 
TTQVGASQYL FPIEEAQGQF LFIVGEGDKT INSKAHAEQA IGQLKRHGKN NWTLLSYPGA 
GHLIEPPYSP LCCASTTHDL RLHWGGEVIP HAAAQEHAWK EIQRFLRKHL IPDVTSQL