Biochemistry and biology of mammalian DNA methyltransferases

Cell Mol Life Sci. 2004 Oct;61(19-20):2571-87. doi: 10.1007/s00018-004-4201-1.


DNA methylation is a stable but not irreversible epigenetic signal that silences gene expression. It has a variety of important functions in mammals, including control of gene expression, cellular differentiation and development, preservation of chromosomal integrity, parental imprinting and X-chromosome inactivation. In addition, it has been implicated in brain function and the development of the immune system. Somatic alterations in genomic methylation patterns contribute to the etiology of human cancers and ageing. It is tightly interwoven with the modification of histone tails and other epigenetic signals. Here we review our current understanding of the molecular enzymology of the mammalian DNA methyltransferases Dnmt1, Dnmt3a, Dnmt3b and Dnmt2 and the roles of the enzymes in the above-mentioned biological processes.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • DNA (Cytosine-5-)-Methyltransferase 1
  • DNA (Cytosine-5-)-Methyltransferases / chemistry*
  • DNA (Cytosine-5-)-Methyltransferases / metabolism
  • DNA (Cytosine-5-)-Methyltransferases / physiology*
  • DNA Methylation
  • DNA Methyltransferase 3A
  • Gene Expression Regulation, Enzymologic*
  • Humans
  • Models, Genetic
  • Signal Transduction


  • DNMT3A protein, human
  • DNA (Cytosine-5-)-Methyltransferase 1
  • DNA (Cytosine-5-)-Methyltransferases
  • DNA Methyltransferase 3A
  • DNA methyltransferase 3B
  • DNMT1 protein, human