Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Original Article
  • Published:

A novel CYP2A6 allele (CYP2A6*35) resulting in an amino-acid substitution (Asn438Tyr) is associated with lower CYP2A6 activity in vivo

Abstract

Cytochrome P450 2A6 (CYP2A6) is the primary human enzyme involved in nicotine metabolism. The objective of this study was to characterize two nonsynonymous single nucleotide polymorphisms in CYP2A6*24, 594G>C (Val110Leu) and 6458A>T (Asn438Tyr). We determined their haplotype, allele frequencies, effect on CYP2A6 activity in vivo, as well as their stability and ability to metabolize nicotine in vitro. CYP2A6*35 (6458A>T) occurred at a frequency of 2.5–2.9% among individuals of black African descent, 0.5–0.8% among Asians and was not found in Caucasians. In addition, we identified two novel alleles, CYP2A6*36 (6458A>T and 6558T>C (Ile471Thr)) and CYP2A6*37 (6458A>T, 6558T>C and 6600G>T (Arg485Leu)). In vivo, CYP2A6*35 was associated with lower CYP2A6 activity as measured by the 3HC/COT ratio. In vitro, CYP2A6.35 had decreased nicotine C-oxidation activity and thermal stability. In conclusion, we identified three novel CYP2A6 alleles (CYP2A6*35, *36 and *37); the higher allele frequency variant CYP2A6*35 was associated with lower CYP2A6 activity.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1

Similar content being viewed by others

References

  1. Benowitz NL . Clinical pharmacology of nicotine: implications for understanding, preventing, and treating tobacco addiction. Clin Pharmacol Ther 2008; 83: 531–541.

    Article  CAS  PubMed  Google Scholar 

  2. Benowitz NL, Jacob III P . Metabolism of nicotine to cotinine studied by a dual stable isotope method. Clin Pharmacol Ther 1994; 56: 483–493.

    Article  CAS  PubMed  Google Scholar 

  3. Minematsu N, Nakamura H, Furuuchi M, Nakajima T, Takahashi S, Tateno H et al. Limitation of cigarette consumption by CYP2A6*4, *7 and *9 polymorphisms. Eur Respir J 2006; 27: 289–292.

    Article  CAS  PubMed  Google Scholar 

  4. Lerman C, Tyndale R, Patterson F, Wileyto EP, Shields PG, Pinto A et al. Nicotine metabolite ratio predicts efficacy of transdermal nicotine for smoking cessation. Clin Pharmacol Ther 2006; 79: 600–608.

    Article  CAS  PubMed  Google Scholar 

  5. Schoedel KA, Hoffmann EB, Rao Y, Sellers EM, Tyndale RF . Ethnic variation in CYP2A6 and association of genetically slow nicotine metabolism and smoking in adult Caucasians. Pharmacogenetics 2004; 14: 615–626.

    Article  CAS  PubMed  Google Scholar 

  6. Patterson F, Schnoll RA, Wileyto EP, Pinto A, Epstein LH, Shields PG et al. Toward personalized therapy for smoking cessation: a randomized placebo-controlled trial of bupropion. Clin Pharmacol Ther 2008; 84: 320–325.

    Article  CAS  PubMed  Google Scholar 

  7. Nakajima M, Yamamoto T, Nunoya K, Yokoi T, Nagashima K, Inoue K et al. Role of human cytochrome P4502A6 in C-oxidation of nicotine. Drug Metab Dispos 1996; 24: 1212–1217.

    CAS  PubMed  Google Scholar 

  8. Messina ES, Tyndale RF, Sellers EM . A major role for CYP2A6 in nicotine C-oxidation by human liver microsomes. J Pharmacol Exp Ther 1997; 282: 1608–1614.

    CAS  PubMed  Google Scholar 

  9. Nakajima M, Yamamoto T, Nunoya K, Yokoi T, Nagashima K, Inoue K et al. Characterization of CYP2A6 involved in 3′-hydroxylation of cotinine in human liver microsomes. J Pharmacol Exp Ther 1996; 277: 1010–1015.

    CAS  PubMed  Google Scholar 

  10. Dempsey D, Tutka P, Jacob III P, Allen F, Schoedel K, Tyndale RF et al. Nicotine metabolite ratio as an index of cytochrome P450 2A6 metabolic activity. Clin Pharmacol Ther 2004; 76: 64–72.

    Article  CAS  PubMed  Google Scholar 

  11. Yamanaka H, Nakajima M, Nishimura K, Yoshida R, Fukami T, Katoh M et al. Metabolic profile of nicotine in subjects whose CYP2A6 gene is deleted. Eur J Pharm Sci 2004; 22: 419–425.

    Article  CAS  PubMed  Google Scholar 

  12. Lea RA, Dickson S, Benowitz NL . Within-subject variation of the salivary 3HC/COT ratio in regular daily smokers: prospects for estimating CYP2A6 enzyme activity in large-scale surveys of nicotine metabolic rate. J Anal Toxicol 2006; 30: 386–389.

    Article  CAS  PubMed  Google Scholar 

  13. Benowitz NL, Jacob III P, Jones RT, Rosenberg J . Interindividual variability in the metabolism and cardiovascular effects of nicotine in man. J Pharmacol Exp Ther 1982; 221: 368–372.

    CAS  PubMed  Google Scholar 

  14. Benowitz NL, Swan GE, Jacob III P, Lessov-Schlaggar CN, Tyndale RF . CYP2A6 genotype and the metabolism and disposition kinetics of nicotine. Clin Pharmacol Ther 2006; 80: 457–467.

    Article  CAS  PubMed  Google Scholar 

  15. Mwenifumbo JC, Al Koudsi N, Ho MK, Zhou Q, Hoffmann EB, Sellers EM et al. Novel and established CYP2A6 alleles impair in vivo nicotine metabolism in a population of Black African descent. Hum Mutat 2008; 29: 679–688.

    Article  CAS  PubMed  Google Scholar 

  16. Mwenifumbo JC, Tyndale RF . Genetic variability in CYP2A6 and the pharmacokinetics of nicotine. Pharmacogenomics 2007; 8: 1385–1402.

    Article  CAS  PubMed  Google Scholar 

  17. Ariyoshi N, Sawamura Y, Kamataki T . A novel single nucleotide polymorphism altering stability and activity of CYP2a6. Biochem Biophys Res Commun 2001; 281: 810–814.

    Article  CAS  PubMed  Google Scholar 

  18. Nakajima M, Fukami T, Yamanaka H, Higashi E, Sakai H, Yoshida R et al. Comprehensive evaluation of variability in nicotine metabolism and CYP2A6 polymorphic alleles in four ethnic populations. Clin Pharmacol Ther 2006; 80: 282–297.

    Article  CAS  PubMed  Google Scholar 

  19. Peamkrasatam S, Sriwatanakul K, Kiyotani K, Fujieda M, Yamazaki H, Kamataki T et al. In vivo evaluation of coumarin and nicotine as probe drugs to predict the metabolic capacity of CYP2A6 due to genetic polymorphism in Thais. Drug Metab Pharmacokinet 2006; 21: 475–484.

    Article  CAS  PubMed  Google Scholar 

  20. Xu C, Rao YS, Xu B, Hoffmann E, Jones J, Sellers EM et al. An in vivo pilot study characterizing the new CYP2A6*7, *8, and *10 alleles. Biochem Biophys Res Commun 2002; 290: 318–324.

    Article  CAS  PubMed  Google Scholar 

  21. Yoshida R, Nakajima M, Watanabe Y, Kwon JT, Yokoi T . Genetic polymorphisms in human CYP2A6 gene causing impaired nicotine metabolism. Br J Clin Pharmacol 2002; 54: 511–517.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  22. Ho MK, Mwenifumbo JC, Al Koudsi N, Okuyemi KS, Ahluwalia JS, Benowitz NL et al. Association of CYP2A6 genotype and phenotype with smoking behaviors and treatment outcomes in African-American light smokers. Clin Pharmacol Ther 2009, advance online publication, 11 March 2009.

  23. Iwahashi K, Waga C, Takimoto T . Whole deletion of CYP2A6 gene (CYP2A6AST;4C) and smoking behavior. Neuropsychobiology 2004; 49: 101–104.

    Article  CAS  PubMed  Google Scholar 

  24. Zhang X, Amemo K, Ameno S, Iwahashi K, Kinoshita H, Kubota T et al. Lack of association between smoking and CYP2A6 gene polymorphisms in A Japanese population. Nihon Arukoru Yakubutsu Igakkai Zasshi 2001; 36: 486–490.

    CAS  PubMed  Google Scholar 

  25. Tan W, Chen GF, Xing DY, Song CY, Kadlubar FF, Lin DX . Frequency of CYP2A6 gene deletion and its relation to risk of lung and esophageal cancer in the Chinese population. Int J Cancer 2001; 95: 96–101.

    Article  CAS  PubMed  Google Scholar 

  26. Lewis DF, Dickins M, Lake BG, Eddershaw PJ, Tarbit MH, Goldfarb PS . Molecular modelling of the human cytochrome P450 isoform CYP2A6 and investigations of CYP2A substrate selectivity. Toxicology 1999; 133: 1–33.

    Article  CAS  PubMed  Google Scholar 

  27. Yano JK, Hsu MH, Griffin KJ, Stout CD, Johnson EF . Structures of human microsomal cytochrome P450 2A6 complexed with coumarin and methoxsalen. Nat Struct Mol Biol 2005; 12: 822–823.

    Article  CAS  PubMed  Google Scholar 

  28. Johnson EF, Stout CD . Structural diversity of human xenobiotic-metabolizing cytochrome P450 monooxygenases. Biochem Biophys Res Commun 2005; 338: 331–336.

    Article  CAS  PubMed  Google Scholar 

  29. Juvonen RO, Iwasaki M, Negishi M . Structural function of residue-209 in coumarin 7-hydroxylase (P450coh). Enzyme-kinetic studies and site-directed mutagenesis. J Biol Chem 1991; 266: 16431–16435.

    CAS  PubMed  Google Scholar 

  30. Pitarque M, von Richter O, Rodriguez-Antona C, Wang J, Oscarson M, Ingelman-Sundberg M . A nicotine C-oxidase gene (CYP2A6) polymorphism important for promoter activity. Hum Mutat 2004; 23: 258–266.

    Article  CAS  PubMed  Google Scholar 

  31. von Richter O, Pitarque M, Rodriguez-Antona C, Testa A, Mantovani R, Oscarson M et al. Polymorphic NF-Y dependent regulation of human nicotine C-oxidase (CYP2A6). Pharmacogenetics 2004; 14: 369–379.

    Article  CAS  PubMed  Google Scholar 

  32. Salavaggione OE, Wang L, Wiepert M, Yee VC, Weinshilboum RM . Thiopurine S-methyltransferase pharmacogenetics: variant allele functional and comparative genomics. Pharmacogenet Genomics 2005; 15: 801–815.

    Article  CAS  PubMed  Google Scholar 

  33. Wang L, Sullivan W, Toft D, Weinshilboum R . Thiopurine S-methyltransferase pharmacogenetics: chaperone protein association and allozyme degradation. Pharmacogenetics 2003; 13: 555–564.

    Article  CAS  PubMed  Google Scholar 

  34. Weinshilboum R, Wang L . Pharmacogenetics: inherited variation in amino acid sequence and altered protein quantity. Clin Pharmacol Ther 2004; 75: 253–258.

    Article  CAS  PubMed  Google Scholar 

  35. Bandiera S, Weidlich S, Harth V, Broede P, Ko Y, Friedberg T . Proteasomal degradation of human CYP1B1: effect of the Asn453Ser polymorphism on the post-translational regulation of CYP1B1 expression. Mol Pharmacol 2005; 67: 435–443.

    Article  CAS  PubMed  Google Scholar 

  36. Malaiyandi V, Lerman C, Benowitz NL, Jepson C, Patterson F, Tyndale RF . Impact of CYP2A6 genotype on pretreatment smoking behaviour and nicotine levels from and usage of nicotine replacement therapy. Mol Psychiatry 2006; 11: 400–409.

    Article  CAS  PubMed  Google Scholar 

  37. Fujieda M, Yamazaki H, Saito T, Kiyotani K, Gyamfi MA, Sakurai M et al. Evaluation of CYP2A6 genetic polymorphisms as determinants of smoking behavior and tobacco-related lung cancer risk in male Japanese smokers. Carcinogenesis 2004; 25: 2451–2458.

    Article  CAS  PubMed  Google Scholar 

  38. Mwenifumbo JC, Lessov-Schlaggar CN, Zhou Q, Krasnow RE, Swan GE, Benowitz NL et al. Identification of novel CYP2A6*1B variants: the CYP2A6*1B allele is associated with faster in vivo nicotine metabolism. Clin Pharmacol Ther 2008; 83: 115–121.

    Article  CAS  PubMed  Google Scholar 

  39. Hoffman SM, Fernandez-Salguero P, Gonzalez FJ, Mohrenweiser HW . Organization and evolution of the cytochrome P450 CYP2A-2B-2F subfamily gene cluster on human chromosome 19. J Mol Evol 1995; 41: 894–900.

    CAS  PubMed  Google Scholar 

  40. Ahluwalia JS, Okuyemi K, Nollen N, Choi WS, Kaur H, Pulvers K et al. The effects of nicotine gum and counseling among African American light smokers: a 2 × 2 factorial design. Addiction 2006; 101: 883–891.

    Article  PubMed  Google Scholar 

  41. Mwenifumbo JC, Sellers EM, Tyndale RF . Nicotine metabolism and CYP2A6 activity in a population of black African descent: impact of gender and light smoking. Drug Alcohol Depend 2007; 89: 24–33.

    Article  CAS  PubMed  Google Scholar 

  42. Ho MK, Mwenifumbo JC, Zhou Q, Hoffmann EB, Okuyemi K, Ahluwalia JS et al. CYP2A6 activity and its association with baseline smoking behaviors and treatment outcomes in a clinical trial of African-American light smokers. POS3-7, pg 87. In: Society for Research on Nicotine and Tobacco (SRNT 14th Annual Meeting): Portland, Oregon 2008.

  43. Gillam EM, Aguinaldo AM, Notley LM, Kim D, Mundkowski RG, Volkov AA et al. Formation of indigo by recombinant mammalian cytochrome P450. Biochem Biophys Res Commun 1999; 265: 469–472.

    Article  CAS  PubMed  Google Scholar 

  44. Ho MK, Mwenifumbo JC, Zhao B, Gillam EM, Tyndale RF . A novel CYP2A6 allele, CYP2A6*23, impairs enzyme function in vitro and in vivo and decreases smoking in a population of Black-African descent. Pharmacogenet Genomics 2008; 18: 67–75.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  45. Siu EC, Wildenauer DB, Tyndale RF . Nicotine self-administration in mice is associated with rates of nicotine inactivation by CYP2A5. Psychopharmacology (Berl) 2006; 184: 401–408.

    Article  CAS  Google Scholar 

  46. Mwenifumbo JC, Sellers EM, Tyndale RF . The association of demographic characteristics with CYP2A6 mediated nicotine metabolism in a population of black African descent. Drug Alcohol Depend 2007; 89: 24–33.

    Article  CAS  PubMed  Google Scholar 

  47. Johnstone E, Benowitz N, Cargill A, Jacob R, Hinks L, Day I et al. Determinants of the rate of nicotine metabolism and effects on smoking behavior. Clin Pharmacol Ther 2006; 80: 319–330.

    Article  CAS  PubMed  Google Scholar 

  48. Nakajima M, Fukami T, Yamanaka H, Higashi E, Sakai H, Yoshida R et al. Comprehensive evaluation of variability in nicotine metabolism and CYP2A6 polymorphic alleles in four ethnic populations. Clin Pharmacol Ther 2006; 80: 282–297.

    Article  CAS  PubMed  Google Scholar 

  49. Benowitz NL, Lessov-Schlaggar CN, Swan GE, Jacob III P . Female sex and oral contraceptive use accelerate nicotine metabolism. Clin Pharmacol Ther 2006; 79: 480–488.

    Article  CAS  PubMed  Google Scholar 

  50. Nakamura K, Ariyoshi N, Yokoi T, Ohgiya S, Chida M, Nagashima K et al. CYP2D6.10 present in human liver microsomes shows low catalytic activity and thermal stability. Biochem Biophys Res Commun 2002; 293: 969–973.

    Article  CAS  PubMed  Google Scholar 

Download references

Acknowledgements

This study was supported by the Centre for Addiction and Mental Health, Canadian Institutes for Health Research (CIHR) MOP86471 and CA91912 (JSA). We thank Bin Zhao, Ewa B Hoffmann, Qian Zhou, Jill C Mwenifumbo, Man Ki Ho and Evan Dorey for technical assistance; Rabindra Shivnaraine for valuable input in data analyses and Sandy Faheim for careful review of the paper. We acknowledge the generous contribution of Dr Benowitz's Lab in measuring the 3HC and COT levels among the African–American population. We also thank Dr Elizabeth Gillam for generous gift of the CYP2A6 construct and Dr Linda Ashworth for generously providing us with cosmid DNA clones 19296, 19019 and 27292 that contain CYP2A6, CYP2A7 and CYP2A13. NK receives funding from CIHR-Strategic Training Program in Tobacco Use in Special Populations (TUSP) and Ontario Graduate Scholarship program (OGS). RFT holds a Canada Research Chair in Pharmacogenetics.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Rachel F Tyndale.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Al Koudsi, N., Ahluwalia, J., Lin, SK. et al. A novel CYP2A6 allele (CYP2A6*35) resulting in an amino-acid substitution (Asn438Tyr) is associated with lower CYP2A6 activity in vivo. Pharmacogenomics J 9, 274–282 (2009). https://doi.org/10.1038/tpj.2009.11

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/tpj.2009.11

Keywords

This article is cited by

Search

Quick links