CYP2A6

CYP2A6
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 4RUI, 1Z10, 1Z11, 2FDU, 2FDV, 2FDW, 2FDY, 3EBS, 3T3Q, 3T3R, 4EJJ
Identifiers
Aliases	CYP2A6, CPA6, CYP2A, CYP2A3, CYPIIA6, P450C2A, P450PB, cytochrome P450 family 2 subfamily A member 6
External IDs	OMIM: 122720; MGI: 88597; HomoloGene: 85917; GeneCards: CYP2A6; OMA:CYP2A6 - orthologs
Gene location (Human) Chr. Chromosome 19 (human) Band 19q13.2 Start 40,843,541 bp End 40,850,447 bp
Gene location (Mouse) Chr. Chromosome 7 (mouse) Band 7 A3|7 15.54 cM Start 26,534,730 bp End 26,542,973 bp
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in right lobe of liver paraflocculus of cerebellum middle frontal gyrus frontal pole Brodmann area 10 nasal epithelium cerebellar vermis male germ cell sperm thalamus Top expressed in proximal tubule human kidney right kidney hepatobiliary system liver esophagus respiratory epithelium thymus nasal epithelium olfactory epithelium More reference expression data BioGPS n/a
Gene ontology Molecular function iron ion binding arachidonic acid epoxygenase activity oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen, reduced flavin or flavoprotein as one donor, and incorporation of one atom of oxygen metal ion binding monooxygenase activity heme binding oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen enzyme binding oxidoreductase activity coumarin 7-hydroxylase activity steroid hydroxylase activity Cellular component organelle membrane endoplasmic reticulum membrane membrane intracellular membrane-bounded organelle endoplasmic reticulum cytoplasmic microtubule cytoplasm Biological process steroid metabolic process epoxygenase P450 pathway coumarin catabolic process coumarin metabolic process organic acid metabolic process xenobiotic metabolic process Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 1548 13087 Ensembl ENSG00000255974 ENSMUSG00000005547 UniProt P11509 P20852 RefSeq (mRNA) NM_000762 NM_007812 RefSeq (protein) NP_000753 n/a Location (UCSC) Chr 19: 40.84 – 40.85 Mb Chr 7: 26.53 – 26.54 Mb PubMed search
Wikidata
View/Edit Human View/Edit Mouse

Cytochrome P450 2A6 (abbreviated CYP2A6) is a member of the cytochrome P450 mixed-function oxidase system, which is involved in the metabolism of xenobiotics in the body. CYP2A6 is the primary enzyme responsible for the oxidation of nicotine and cotinine. It is also involved in the metabolism of several pharmaceuticals, carcinogens, and a number of coumarin-type alkaloids. CYP2A6 is the only enzyme in the human body that appreciably catalyzes the 7-hydroxylation of coumarin, such that the formation of the product of this reaction, 7-hydroxycoumarin, is used as a probe for CYP2A6 activity.

The CYP2A6 gene is part of a large cluster of cytochrome P450 genes from the CYP2A, CYP2B and CYP2F subfamilies on chromosome 19q. The gene was formerly referred to as CYP2A3; however, it has been renamed CYP2A6.

Interactive pathway map

Click on genes, proteins and metabolites below to link to respective articles.

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|alt=Fluorouracil (5-FU) Activity edit]]

Fluorouracil (5-FU) Activity edit

Distribution

CYP2A6 localizes to the endoplasmic reticulum and is found predominantly in the liver.

Variability

Significant interindividual variability in CYP2A6 apoprotein and mRNA levels has been observed.

Induction

CYP2A6 is known to be inducible by phenobarbital and rifampicin, and it is suspected that other antiepileptic drugs may also have this effect.

CYP2A6 Ligands

Selected inducers, inhibitors and substrates of CYP2A6

Substrates	Inhibitors	Inducers
Many Carcinogens MNAN NNK NDEA MTBE Other toxins aflatoxin B1 (mycotoxin) 1,3-butadiene (in synthetic rubber) coumarin (anticoagulant, found in cinnamon) DCBN (herbicide) 7-ethoxycoumarin (test substrate) skatole quinoline MOCA (in polyurethane production) halothane (anaesthetic) losigamone (anticonvulsant) methoxyflurane (anaesthetic) cotinine (metabolite of nicotine) nicotine (stimulant) SM-12502 (PAF antagonist) valproic acid (anticonvulsant, mood-stabilizing) dexmedetomidine (sedative)	amiodarone (antiarrhythmic agent) amlodipine (calcium channel blocker) buprenorphine (semisynthetic opioid) clofibrate (fibrate) clotrimazole (antifungal) desipramine (tricyclic antidepressant) disulfiram (acetaldehyde dehydrogenase inhibitor) entacapone (COMT inhibitor, used in Parkinson's disease) fenofibrate (fibrate) gabapentin (anticonvulsant) grapefruit juice flavonoids isoniazid (antibacterial) ketoconazole (antifungal) letrozole (aromatase inhibitor, used in breast cancer) methimazole (antithyroid agent) methoxsalen (furanocoumarin, used in psoriasis) metyrapone (used to diagnose adrenal insufficiency) miconazole (antifungal) modafinil (wakefulness-promoting agent) nicotine (stimulant) orphenadrine (antihistamine) pilocarpine (muscarinic receptor agonist) pregabalin (anticonvulsant) selegiline (monoamine oxidase inhibitor) sulconazole (antifungal) tioconazole (antifungal) tranylcypromine (monoamine oxidase inhibitor)	Barbiturates amobarbital pentobarbital phenobarbital secobarbital rifampicin (antibacterial)

See also

• List of cytochrome P450 modulators

Further reading

• Pelkonen O, Rautio A, Raunio H, Pasanen M (2000). "CYP2A6: a human coumarin 7-hydroxylase". Toxicology. 144 (1–3): 139–47. doi:10.1016/S0300-483X(99)00200-0. PMID 10781881.
• Fernandez-Salguero P, Gonzalez FJ (1995). "The CYP2A gene subfamily: species differences, regulation, catalytic activities and role in chemical carcinogenesis". Pharmacogenetics. 5 (Special Issue): S123–8. doi:10.1097/00008571-199512001-00013. PMID 7581481.
• Smith G, Stubbins MJ, Harries LW, Wolf CR (1999). "Molecular genetics of the human cytochrome P450 monooxygenase superfamily". Xenobiotica. 28 (12): 1129–65. doi:10.1080/004982598238868. PMID 9890157.
• Pelkonen O, Rautio A, Raunio H, Pasanen M (2000). "CYP2A6: a human coumarin 7-hydroxylase". Toxicology. 144 (1–3): 139–47. doi:10.1016/S0300-483X(99)00200-0. PMID 10781881.
• Tyndale RF, Sellers EM (2002). "Genetic variation in CYP2A6-mediated nicotine metabolism alters smoking behavior". Therapeutic Drug Monitoring. 24 (1): 163–71. doi:10.1097/00007691-200202000-00026. PMID 11805739. S2CID 12837210.
• Xu C, Goodz S, Sellers EM, Tyndale RF (2003). "CYP2A6 genetic variation and potential consequences". Adv. Drug Deliv. Rev. 54 (10): 1245–56. doi:10.1016/S0169-409X(02)00065-0. PMID 12406643.
• Kamataki T, Fujieda M, Kiyotani K, et al. (2005). "Genetic polymorphism of CYP2A6 as one of the potential determinants of tobacco-related cancer risk". Biochem. Biophys. Res. Commun. 338 (1): 306–10. doi:10.1016/j.bbrc.2005.08.268. PMID 16176798.
• Maurice M, Emiliani S, Dalet-Beluche I, et al. (1991). "Isolation and characterization of a cytochrome P450 of the IIA subfamily from human liver microsomes". Eur. J. Biochem. 200 (2): 511–7. doi:10.1111/j.1432-1033.1991.tb16212.x. PMID 1889415.
• Yun CH, Shimada T, Guengerich FP (1991). "Purification and characterization of human liver microsomal cytochrome P-450 2A6". Mol. Pharmacol. 40 (5): 679–85. PMID 1944238.
• Yamano S, Tatsuno J, Gonzalez FJ (1990). "The CYP2A3 gene product catalyzes coumarin 7-hydroxylation in human liver microsomes". Biochemistry. 29 (5): 1322–9. doi:10.1021/bi00457a031. PMID 2322567.
• Miles JS, Bickmore W, Brook JD, et al. (1989). "Close linkage of the human cytochrome P450IIA and P450IIB gene subfamilies: implications for the assignment of substrate specificity". Nucleic Acids Res. 17 (8): 2907–17. doi:10.1093/nar/17.8.2907. PMC 317701. PMID 2726448.
• Yamano S, Nagata K, Yamazoe Y, et al. (1989). "cDNA and deduced amino acid sequences of human P450 IIA3 (CYP2A3)". Nucleic Acids Res. 17 (12): 4888. doi:10.1093/nar/17.12.4888. PMC 318052. PMID 2748347.
• Phillips IR, Shephard EA, Ashworth A, Rabin BR (1985). "Isolation and sequence of a human cytochrome P-450 cDNA clone". Proc. Natl. Acad. Sci. U.S.A. 82 (4): 983–7. Bibcode:1985PNAS...82..983P. doi:10.1073/pnas.82.4.983. PMC 397177. PMID 3856261.
• Wainwright BJ, Watson EK, Shephard EA, Phillips IR (1985). "RFLP for a human cytochrome P-450 gene at 19q13.1-qter (HGM8 provisional designation CYPI)". Nucleic Acids Res. 13 (12): 4610. doi:10.1093/nar/13.12.4610. PMC 321810. PMID 4011450.
• Fernandez-Salguero P, Hoffman SM, Cholerton S, et al. (1995). "A genetic polymorphism in coumarin 7-hydroxylation: sequence of the human CYP2A genes and identification of variant CYP2A6 alleles". Am. J. Hum. Genet. 57 (3): 651–60. PMC 1801261. PMID 7668294.
• Ding S, Lake BG, Friedberg T, Wolf CR (1995). "Expression and alternative splicing of the cytochrome P-450 CYP2A7". Biochem. J. 306. ( Pt 1) (Pt 1): 161–6. doi:10.1042/bj3060161. PMC 1136496. PMID 7864805.
• Hoffman SM, Fernandez-Salguero P, Gonzalez FJ, Mohrenweiser HW (1996). "Organization and evolution of the cytochrome P450 CYP2A-2B-2F subfamily gene cluster on human chromosome 19". J. Mol. Evol. 41 (6): 894–900. doi:10.1007/bf00173169. PMID 8587134. S2CID 12153961.
• Hadidi H, Zahlsen K, Idle JR, Cholerton S (1998). "A single amino acid substitution (Leu160His) in cytochrome P450 CYP2A6 causes switching from 7-hydroxylation to 3-hydroxylation of coumarin". Food Chem. Toxicol. 35 (9): 903–7. doi:10.1016/S0278-6915(97)00066-5. PMID 9409631.
• Oscarson M, Gullstén H, Rautio A, et al. (1998). "Genotyping of human cytochrome P450 2A6 (CYP2A6), a nicotine C-oxidase". FEBS Lett. 438 (3): 201–5. Bibcode:1998FEBSL.438..201O. doi:10.1016/S0014-5793(98)01297-6. PMID 9827545. S2CID 1250823.

External links

• Human CPA6 genome location and CPA6 gene details page in the UCSC Genome Browser.
• Human CYP2A6 genome location and CYP2A6 gene details page in the UCSC Genome Browser.