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.

  • Article
  • Published:

AID/APOBEC deaminases disfavor modified cytosines implicated in DNA demethylation

Abstract

Activation-induced deaminase (AID)/APOBEC–family cytosine deaminases, known to function in diverse cellular processes from antibody diversification to mRNA editing, have also been implicated in DNA demethylation, a major process for transcriptional activation. Although oxidation-dependent pathways for demethylation have been described, pathways involving deamination of either 5-methylcytosine (5mC) or 5-hydroxymethylcytosine (5hmC) have emerged as alternatives. Here we address the biochemical plausibility of deamination-coupled demethylation. We found that purified AID/APOBECs have substantially reduced activity on 5mC relative to cytosine, their canonical substrate, and no detectable deamination of 5hmC. This finding was explained by the reactivity of a series of modified substrates, where steric bulk was increasingly detrimental to deamination. Further, upon AID/APOBEC overexpression, the deamination product of 5hmC was undetectable in genomic DNA, whereas oxidation intermediates remained detectable. Our results indicate that the steric requirements for cytosine deamination are one intrinsic barrier to the proposed function of deaminases in DNA demethylation.

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: Proposed noncanonical role for AID/APOBEC enzymes acting on modified cytosine substrates in DNA.
Figure 2: AID/APOBEC enzymes preferentially deaminate unmodified cytosine.
Figure 3: DNA deamination decreases as a function of increasing steric bulk at the 5 position of cytosine.
Figure 4: AID/APOBEC enzymes do not perturb levels of 5mC oxidation intermediates in genomic DNA.

Similar content being viewed by others

References

  1. Nabel, C.S., Manning, S.A. & Kohli, R.M. The curious chemical biology of cytosine: deamination, methylation, and oxidation as modulators of genomic potential. 7, 20–30 ACS Chem. Biol. (2012).

    Article  CAS  Google Scholar 

  2. Rosenberg, B.R. & Papavasiliou, F.N. Beyond SHM and CSR: AID and related cytidine deaminases in the host response to viral infection. Adv. Immunol. 94, 215–244 (2007).

    Article  CAS  Google Scholar 

  3. Teperek-Tkacz, M., Pasque, V., Gentsch, G. & Ferguson-Smith, A.C. Epigenetic reprogramming: is deamination key to active DNA demethylation? Reproduction 142, 621–632 (2011).

    Article  CAS  Google Scholar 

  4. Fritz, E.L. & Papavasiliou, F.N. Cytidine deaminases: AIDing DNA demethylation? Genes Dev. 24, 2107–2114 (2010).

    Article  CAS  Google Scholar 

  5. Bird, A. DNA methylation patterns and epigenetic memory. Genes Dev. 16, 6–21 (2002).

    Article  CAS  Google Scholar 

  6. Tahiliani, M. et al. Conversion of 5-methylcytosine to 5-hydroxymethylcytosine in mammalian DNA by MLL partner TET1. Science 324, 930–935 (2009).

    Article  CAS  Google Scholar 

  7. Ito, S. et al. Role of Tet proteins in 5mC to 5hmC conversion, ES-cell self-renewal and inner cell mass specification. Nature 466, 1129–1133 (2010).

    Article  CAS  Google Scholar 

  8. Münzel, M., Globisch, D. & Carell, T. 5-Hydroxymethylcytosine, the sixth base of the genome. Angew. Chem. Int. Edn Engl. 50, 6460–6468 (2011).

    Article  Google Scholar 

  9. Wu, H. & Zhang, Y. Mechanisms and functions of Tet protein-mediated 5-methylcytosine oxidation. Genes Dev. 25, 2436–2452 (2011).

    Article  CAS  Google Scholar 

  10. Pastor, W.A. et al. Genome-wide mapping of 5-hydroxymethylcytosine in embryonic stem cells. Nature 473, 394–397 (2011).

    Article  CAS  Google Scholar 

  11. Hajkova, P. Epigenetic reprogramming in the germline: towards the ground state of the epigenome. Phil. Trans. R. Soc. Lond. B 366, 2266–2273 (2011).

    Article  CAS  Google Scholar 

  12. Wu, S.C. & Zhang, Y. Active DNA demethylation: many roads lead to Rome. Nat. Rev. Mol. Cell Biol. 11, 607–620 (2010).

    Article  CAS  Google Scholar 

  13. Morgan, H.D., Dean, W., Coker, H.A., Reik, W. & Petersen-Mahrt, S.K. Activation-induced cytidine deaminase deaminates 5-methylcytosine in DNA and is expressed in pluripotent tissues: implications for epigenetic reprogramming. J. Biol. Chem. 279, 52353–52360 (2004).

    Article  CAS  Google Scholar 

  14. Guo, J.U., Su, Y., Zhong, C., Ming, G.L. & Song, H. Hydroxylation of 5-methylcytosine by TET1 promotes active DNA demethylation in the adult brain. Cell 145, 423–434 (2011).

    Article  CAS  Google Scholar 

  15. Ito, S. et al. Tet proteins can convert 5-methylcytosine to 5-formylcytosine and 5-carboxylcytosine. Science 333, 1300–1303 (2011).

    Article  CAS  Google Scholar 

  16. He, Y.F. et al. Tet-mediated formation of 5-carboxylcytosine and its excision by TDG in mammalian DNA. Science 333, 1303–1307 (2011).

    Article  CAS  Google Scholar 

  17. Maiti, A. & Drohat, A.C. Thymine DNA glycosylase can rapidly excise 5-formylcytosine and 5-carboxylcytosine: potential implications for active demethylation of CpG sites. J. Biol. Chem. 286, 35334–35338 (2011).

    Article  CAS  Google Scholar 

  18. Pfaffeneder, T. et al. The discovery of 5-formylcytosine in embryonic stem cell DNA. Angew. Chem. Int. Edn Engl. 50, 7008–7012 (2011).

    Article  CAS  Google Scholar 

  19. Zhang, L. et al. Thymine DNA glycosylase specifically recognizes 5-carboxylcytosine-modified DNA. Nat. Chem. Biol. 8, 328–330 (2012).

    Article  CAS  Google Scholar 

  20. Cortázar, D. et al. Embryonic lethal phenotype reveals a function of TDG in maintaining epigenetic stability. Nature 470, 419–423 (2011).

    Article  Google Scholar 

  21. Cortellino, S. et al. Thymine DNA glycosylase is essential for active DNA demethylation by linked deamination-base excision repair. Cell 146, 67–79 (2011).

    Article  CAS  Google Scholar 

  22. Conticello, S.G., Langlois, M.A., Yang, Z. & Neuberger, M.S. DNA deamination in immunity: AID in the context of its APOBEC relatives. Adv. Immunol. 94, 37–73 (2007).

    Article  CAS  Google Scholar 

  23. Bransteitter, R., Pham, P., Scharff, M.D. & Goodman, M.F. Activation-induced cytidine deaminase deaminates deoxycytidine on single-stranded DNA but requires the action of RNase. Proc. Natl. Acad. Sci. USA 100, 4102–4107 (2003).

    Article  CAS  Google Scholar 

  24. Larijani, M. et al. Methylation protects cytidines from AID-mediated deamination. Mol. Immunol. 42, 599–604 (2005).

    Article  CAS  Google Scholar 

  25. Bhutani, N. et al. Reprogramming towards pluripotency requires AID-dependent DNA demethylation. Nature 463, 1042–1047 (2010).

    Article  CAS  Google Scholar 

  26. Popp, C. et al. Genome-wide erasure of DNA methylation in mouse primordial germ cells is affected by AID deficiency. Nature 463, 1101–1105 (2010).

    Article  CAS  Google Scholar 

  27. Muramatsu, M. et al. Class switch recombination and hypermutation require activation-induced cytidine deaminase (AID), a potential RNA editing enzyme. Cell 102, 553–563 (2000).

    Article  CAS  Google Scholar 

  28. Rai, K. et al. DNA demethylation in zebrafish involves the coupling of a deaminase, a glycosylase, and gadd45. Cell 135, 1201–1212 (2008).

    Article  CAS  Google Scholar 

  29. Kohli, R.M. et al. A portable hotspot recognition loop transfers sequence preferences from APOBEC family members to activation-induced cytidine deaminase. J. Biol. Chem. 284, 22898–22904 (2009).

    Article  CAS  Google Scholar 

  30. Larijani, M., Frieder, D., Basit, W. & Martin, A. The mutation spectrum of purified AID is similar to the mutability index in Ramos cells and in ung(−/−) msh2(−/−) mice. Immunogenetics 56, 840–845 (2005).

    Article  CAS  Google Scholar 

  31. Beale, R.C. et al. Comparison of the differential context-dependence of DNA deamination by APOBEC enzymes: correlation with mutation spectra in vivo. J. Mol. Biol. 337, 585–596 (2004).

    Article  CAS  Google Scholar 

  32. Prochnow, C., Bransteitter, R., Klein, M.G., Goodman, M.F. & Chen, X.S. The APOBEC-2 crystal structure and functional implications for the deaminase AID. Nature 445, 447–451 (2007).

    Article  CAS  Google Scholar 

  33. Hansch, C. et al. “Aromatic” substituent constants for structure-activity correlations. J. Med. Chem. 16, 1207–1216 (1973).

    Article  CAS  Google Scholar 

  34. Pearl, L.H. Structure and function in the uracil-DNA glycosylase superfamily. Mutat. Res. 460, 165–181 (2000).

    Article  CAS  Google Scholar 

  35. Bennett, M.T. et al. Specificity of human thymine DNA glycosylase depends on N-glycosidic bond stability. J. Am. Chem. Soc. 128, 12510–12519 (2006).

    Article  CAS  Google Scholar 

  36. Kavli, B. et al. Excision of cytosine and thymine from DNA by mutants of human uracil-DNA glycosylase. EMBO J. 15, 3442–3447 (1996).

    Article  CAS  Google Scholar 

  37. Guo, J.U., Su, Y., Zhong, C., Ming, G.L. & Song, H. Emerging roles of TET proteins and 5-hydroxymethylcytosines in active DNA demethylation and beyond. Cell Cycle 10, 2662–2668 (2011).

    Article  CAS  Google Scholar 

  38. Globisch, D. et al. Tissue distribution of 5-hydroxymethylcytosine and search for active demethylation intermediates. PLoS ONE 5, e15367 (2010).

    Article  CAS  Google Scholar 

  39. Kohli, R.M. et al. Local sequence targeting in the AID/APOBEC family differentially impacts retroviral restriction and antibody diversification. J. Biol. Chem. 285, 40956–40964 (2010).

    Article  CAS  Google Scholar 

  40. Pham, P., Bransteitter, R., Petruska, J. & Goodman, M.F. Processive AID-catalysed cytosine deamination on single-stranded DNA simulates somatic hypermutation. Nature 424, 103–107 (2003).

    Article  CAS  Google Scholar 

  41. Bruniquel, D. & Schwartz, R.H. Selective, stable demethylation of the interleukin-2 gene enhances transcription by an active process. Nat. Immunol. 4, 235–240 (2003).

    Article  CAS  Google Scholar 

  42. Martinowich, K. et al. DNA methylation-related chromatin remodeling in activity-dependent BDNF gene regulation. Science 302, 890–893 (2003).

    Article  CAS  Google Scholar 

  43. Liu, M. et al. Two levels of protection for the B cell genome during somatic hypermutation. Nature 451, 841–845 (2008).

    Article  CAS  Google Scholar 

  44. Landry, S., Narvaiza, I., Linfesty, D.C. & Weitzman, M.D. APOBEC3A can activate the DNA damage response and cause cell-cycle arrest. EMBO Rep. 12, 444–450 (2011).

    Article  CAS  Google Scholar 

  45. Grogan, B.C., Parker, J.B., Guminski, A.F. & Stivers, J.T. Effect of the thymidylate synthase inhibitors on dUTP and TTP pool levels and the activities of DNA repair glycosylases on uracil and 5-fluorouracil in DNA. Biochemistry 50, 618–627 (2011).

    Article  CAS  Google Scholar 

Download references

Acknowledgements

We are grateful to M. Bartolomei, M. Weitzman and M. Lazar for helpful discussions, K. Gajula and S. Manning for technical assistance and the University of North Carolina Biomarker Mass Spectrometry Facility for guidance. We are also grateful for A. Drohat (University of Maryland), A. Guminski (Johns Hopkins University) and J. Guo and H. Song (Johns Hopkins University) for providing reagents. This work was supported in part by the Rita Allen Foundation (to R.M.K.), the W. W. Smith Charitable Trust (to R.M.K.) and US National Institutes of Health grants K08-AI089242 (to R.M.K.), GM056834 (to J.T.S.) and U01DK089565 (to Y.Z.). Y.Z. is an investigator of the Howard Hughes Medical Institute.

Author information

Authors and Affiliations

Authors

Contributions

R.M.K., J.T.S. and Y.Z. conceived the project. R.M.K., J.T.S., Y.Y., C.S.N. and Y.Z. designed the experiments. C.S.N., H.J., Y.Y., L.S. and H.L.G. performed the experiments. C.S.N., H.J. and L.S. analyzed the data. C.S.N., H.J., L.S., H.L.G., J.T.S., Y.Z. and R.M.K. interpreted the data. C.S.N., J.T.S. and R.M.K. wrote the manuscript, and all authors edited the manuscript.

Corresponding authors

Correspondence to Yi Zhang or Rahul M Kohli.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Text and Figures

Supplementary Methods and Supplementary Results (PDF 1000 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Nabel, C., Jia, H., Ye, Y. et al. AID/APOBEC deaminases disfavor modified cytosines implicated in DNA demethylation. Nat Chem Biol 8, 751–758 (2012). https://doi.org/10.1038/nchembio.1042

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nchembio.1042

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing