The R882H DNMT3A mutation associated with AML dominantly inhibits wild-type DNMT3A by blocking its ability to form active tetramers

Cancer Cell. 2014 Apr 14;25(4):442-54. doi: 10.1016/j.ccr.2014.02.010. Epub 2014 Mar 20.

Abstract

Somatic mutations in DNMT3A, which encodes a de novo DNA methyltransferase, are found in ∼30% of normal karyotype acute myeloid leukemia (AML) cases. Most mutations are heterozygous and alter R882 within the catalytic domain (most commonly R882H), suggesting the possibility of dominant-negative consequences. The methyltransferase activity of R882H DNMT3A is reduced by ∼80% compared with the WT enzyme. In vitro mixing of WT and R882H DNMT3A does not affect the WT activity, but coexpression of the two proteins in cells profoundly inhibits the WT enzyme by disrupting its ability to homotetramerize. AML cells with the R882H mutation have severely reduced de novo methyltransferase activity and focal hypomethylation at specific CpGs throughout AML cell genomes.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Amino Acid Sequence
  • DNA (Cytosine-5-)-Methyltransferases / chemistry
  • DNA (Cytosine-5-)-Methyltransferases / genetics*
  • DNA Methylation
  • Humans
  • Leukemia, Myeloid, Acute / enzymology*
  • Leukemia, Myeloid, Acute / genetics*
  • Models, Molecular
  • Molecular Sequence Data
  • Mutation*
  • Prognosis
  • Protein Conformation

Substances

  • DNA (Cytosine-5-)-Methyltransferases
  • DNA methyltransferase 3A