Degree of recruitment of DOT1L to MLL-AF9 defines level of H3K79 Di- and tri-methylation on target genes and transformation potential

Cell Rep. 2015 May 5;11(5):808-20. doi: 10.1016/j.celrep.2015.04.004. Epub 2015 Apr 23.

Abstract

The MLL gene is a common target of chromosomal translocations found in human leukemia. MLL-fusion leukemia has a consistently poor outcome. One of the most common translocation partners is AF9 (MLLT3). MLL-AF9 recruits DOT1L, a histone 3 lysine 79 methyltransferase (H3K79me1/me2/me3), leading to aberrant gene transcription. We show that DOT1L has three AF9 binding sites and present the nuclear magnetic resonance (NMR) solution structure of a DOT1L-AF9 complex. We generate structure-guided point mutations and find that they have graded effects on recruitment of DOT1L to MLL-AF9. Chromatin immunoprecipitation sequencing (ChIP-seq) analyses of H3K79me2 and H3K79me3 show that graded reduction of the DOT1L interaction with MLL-AF9 results in differential loss of H3K79me2 and me3 at MLL-AF9 target genes. Furthermore, the degree of DOT1L recruitment is linked to the level of MLL-AF9 hematopoietic transformation.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Binding Sites
  • Chromatin Immunoprecipitation
  • Histone-Lysine N-Methyltransferase
  • Histones / metabolism*
  • Humans
  • Magnetic Resonance Spectroscopy
  • Methylation
  • Methyltransferases / chemistry
  • Methyltransferases / genetics
  • Methyltransferases / metabolism*
  • Molecular Sequence Data
  • Myeloid-Lymphoid Leukemia Protein / chemistry
  • Myeloid-Lymphoid Leukemia Protein / genetics
  • Myeloid-Lymphoid Leukemia Protein / metabolism*
  • Oncogene Proteins, Fusion / chemistry
  • Oncogene Proteins, Fusion / genetics
  • Oncogene Proteins, Fusion / metabolism*
  • Point Mutation
  • Protein Binding
  • Protein Structure, Tertiary
  • Recombinant Proteins / biosynthesis
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Sequence Analysis, DNA

Substances

  • Histones
  • MLL-AF9 fusion protein, human
  • Oncogene Proteins, Fusion
  • Recombinant Proteins
  • Myeloid-Lymphoid Leukemia Protein
  • DOT1L protein, human
  • Methyltransferases
  • Histone-Lysine N-Methyltransferase