The C-terminal domain of Brd2 is important for chromatin interaction and regulation of transcription and alternative splicing

Mol Biol Cell. 2013 Nov;24(22):3557-68. doi: 10.1091/mbc.E13-06-0303. Epub 2013 Sep 18.

Abstract

Brd2 is a member of the bromodomain extra terminal (BET) protein family, which consists of four chromatin-interacting proteins that regulate gene expression. Each BET protein contains two N-terminal bromodomains, which recognize acetylated histones, and the C-terminal protein-protein interaction domain. Using a genome-wide screen, we identify 1450 genes whose transcription is regulated by Brd2. In addition, almost 290 genes change their alternative splicing pattern upon Brd2 depletion. Brd2 is specifically localized at promoters of target genes, and our data show that Brd2 interaction with chromatin cannot be explained solely by histone acetylation. Using coimmunoprecipitation and live-cell imaging, we show that the C-terminal part is crucial for Brd2 association with chromatin. Live-cell microscopy also allows us to map the average binding time of Brd2 to chromatin and quantify the contributions of individual Brd2 domains to the interaction with chromatin. Finally, we show that bromodomains and the C-terminal domain are equally important for transcription and splicing regulation, which correlates with the role of these domains in Brd2 binding to chromatin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alternative Splicing
  • Chromatin / metabolism*
  • Gene Expression Regulation*
  • Genome, Human*
  • HeLa Cells
  • Histones / genetics*
  • Histones / metabolism
  • Humans
  • Microscopy, Video
  • Promoter Regions, Genetic
  • Protein Binding
  • Protein Serine-Threonine Kinases / genetics*
  • Protein Serine-Threonine Kinases / metabolism
  • Protein Structure, Tertiary
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Signal Transduction
  • Transcription Factors
  • Transcription, Genetic

Substances

  • BRD2 protein, human
  • Chromatin
  • Histones
  • Recombinant Fusion Proteins
  • Transcription Factors
  • Protein Serine-Threonine Kinases