EP400 Deposits H3.3 into Promoters and Enhancers during Gene Activation

Mol Cell. 2016 Jan 7;61(1):27-38. doi: 10.1016/j.molcel.2015.10.039. Epub 2015 Dec 6.


Gene activation in metazoans is accompanied by the presence of histone variants H2AZ and H3.3 within promoters and enhancers. It is not known, however, what protein deposits H3.3 into chromatin or whether variant chromatin plays a direct role in gene activation. Here we show that chromatin containing acetylated H2AZ and H3.3 stimulates transcription in vitro. Analysis of the Pol II pre-initiation complex on immobilized chromatin templates revealed that the E1A binding protein p400 (EP400) was bound preferentially to and required for transcription stimulation by acetylated double-variant chromatin. EP400 also stimulated H2AZ/H3.3 deposition into promoters and enhancers and influenced transcription in vivo at a step downstream of the Mediator complex. EP400 efficiently exchanged recombinant histones H2A and H3.1 with H2AZ and H3.3, respectively, in a chromatin- and ATP-stimulated manner in vitro. Our data reveal that EP400 deposits H3.3 into chromatin alongside H2AZ and contributes to gene regulation after PIC assembly.

Keywords: EP400; H2AZ; H3.3; RNA polymerase II; histone exchange; pre-initiation complex (PIC).

Publication types

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

MeSH terms

  • Acetylation
  • Adenosine Triphosphate / metabolism
  • Binding Sites
  • Cell Line, Tumor
  • Chromatin Assembly and Disassembly*
  • DNA Helicases / genetics
  • DNA Helicases / metabolism*
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Gene Expression Regulation*
  • Genes, Reporter
  • Histones / genetics
  • Histones / metabolism*
  • Humans
  • Promoter Regions, Genetic*
  • RNA Interference
  • RNA Polymerase II / metabolism
  • Time Factors
  • Transcriptional Activation*
  • Transfection


  • DNA-Binding Proteins
  • Histones
  • histone H2A.F-Z
  • Adenosine Triphosphate
  • RNA Polymerase II
  • DNA Helicases
  • EP400 protein, human