NR1I3 (nuclear receptor subfamily 1 group I member 3)

Gene

• Entrez ID: 9970
• Gene name: Nuclear receptor subfamily 1 group I member 3
• Gene symbol: NR1I3
• Synonyms: CAR, CAR1, MB67
• Chromosome: 1
• Chromosome location: 1q23.3
• Summary: This gene encodes a member of the nuclear receptor superfamily, and is a key regulator of xenobiotic and endobiotic metabolism. The protein binds to DNA as a monomer or a heterodimer with the retinoid X receptor and regulates the transcription of target genes involved in drug metabolism and bilirubin clearance, such as cytochrome P450 family members. Unlike most nuclear receptors, this transcriptional regulator is constitutively active in the absence of ligand but is regulated by both agonists and inverse agonists. Ligand binding results in translocation of this protein to the nucleus, where it activates or represses target gene transcription. These ligands include bilirubin, a variety of foreign compounds, steroid hormones, and prescription drugs. In addition to drug metabolism, the CAR protein is also reported to regulate genes involved in glucose metabolism, lipid metabolism, cell proliferation, and circadian clock regulation. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2020]

Transcription factors

Transcription factor	Regulation	Reference
RARA	Activation	20211151

Gene ontology (GO)

GO ID	Ontology	Definition	Evidence	Reference
GO:0000122	Process	Negative regulation of transcription by RNA polymerase II	IBA	21873635
GO:0000785	Component	Chromatin	ISA
GO:0000977	Function	RNA polymerase II transcription regulatory region sequence-specific DNA binding	IDA	11114890
GO:0000978	Function	RNA polymerase II cis-regulatory region sequence-specific DNA binding	IBA	21873635
GO:0000978	Function	RNA polymerase II cis-regulatory region sequence-specific DNA binding	TAS	9783588
GO:0000981	Function	DNA-binding transcription factor activity, RNA polymerase II-specific	ISA
GO:0001228	Function	DNA-binding transcription activator activity, RNA polymerase II-specific	IDA	11114890
GO:0003700	Function	DNA-binding transcription factor activity	TAS	8114692
GO:0004879	Function	Nuclear receptor activity	IBA	21873635
GO:0004879	Function	Nuclear receptor activity	IDA	9783588
GO:0005515	Function	Protein binding	IPI	32814053
GO:0005634	Component	Nucleus	ISS
GO:0005654	Component	Nucleoplasm	IDA
GO:0005654	Component	Nucleoplasm	TAS
GO:0005737	Component	Cytoplasm	ISS
GO:0005829	Component	Cytosol	IEA
GO:0005856	Component	Cytoskeleton	IEA
GO:0006367	Process	Transcription initiation from RNA polymerase II promoter	TAS
GO:0007165	Process	Signal transduction	TAS
GO:0008270	Function	Zinc ion binding	IEA
GO:0030154	Process	Cell differentiation	IBA	21873635
GO:0030522	Process	Intracellular receptor signaling pathway	IEA
GO:0045944	Process	Positive regulation of transcription by RNA polymerase II	IBA	21873635
GO:0045944	Process	Positive regulation of transcription by RNA polymerase II	IDA	11114890
GO:1990837	Function	Sequence-specific double-stranded DNA binding	IDA	28473536

Other IDs

• MIM: 603881
• HGNC: 7969
• e!Ensembl: ENSG00000143257

Protein

• UniProt ID: Q14994
• Protein name: Nuclear receptor subfamily 1 group I member 3 (Constitutive activator of retinoid response) (Constitutive active response) (Constitutive androstane receptor) (CAR) (Orphan nuclear receptor MB67)
• Protein function: Binds and transactivates the retinoic acid response elements that control expression of the retinoic acid receptor beta 2 and alcohol dehydrogenase 3 genes. Transactivates both the phenobarbital responsive element module of the human CYP2B6 gene and the CYP3A4 xenobiotic response element.
• PDB: 1XV9, 1XVP
• Family and domains:

  Pfam

  Accession	ID	Position in sequence	Description	Type
  PF00105	zf-C4	9 → 78	Zinc finger, C4 type (two domains)	Domain
  PF00104	Hormone_recep	157 → 338	Ligand-binding domain of nuclear hormone receptor	Domain

• Sequence:

  MASREDELRNCVVCGDQATGYHFNALTCEGCKGFFRRTVSKSIGPTCPFAGSCEVSKTQR
  RHCPACRLQKCLDAGMRKDMILSAEALALRRAKQAQRRAQQTPVQLSKEQEELIRTLLGA
  HTRHMGTMFEQFVQFRPPAHLFIHHQPLPTLAPVLPLVTHFADINTFMVLQVIKFTKDLP
  VFRSLPIEDQISLLKGAAVEICHIVLNTTFCLQTQNFLCGPLRYTIEDGARVSPTVGFQV
  EFLELLFHFHGTLRKLQLQEPEYVLLAAMALFSPDRPGVTQRDEIDQLQEEMALTLQSYI
  KGQQRRPRDRFLYAKLLGLLAELRSINEAYGYQIQHIQGLSAMMPLLQEICS

• Sequence length: 352

Pathways

Reactome:

Nuclear Receptor transcription pathway

Associated diseases

Disease name	Disease term	References
	Diabetes Mellitus	20869355
	Hepatocellular Adenoma	25656644
	Liver neoplasms	28218408, 19233941, 22293087, 24449422, 19482888
	Malignant neoplasm of liver	24449422, 22293087, 19482888, 28218408, 19233941
	Metabolic Syndrome X	20869355
	Obesity	20869355