TRIM28 repression of retrotransposon-based enhancers is necessary to preserve transcriptional dynamics in embryonic stem cells

Genome Res. 2013 Mar;23(3):452-61. doi: 10.1101/gr.147678.112. Epub 2012 Dec 10.

Abstract

TRIM28 is critical for the silencing of endogenous retroviruses (ERVs) in embryonic stem (ES) cells. Here, we reveal that an essential impact of this process is the protection of cellular gene expression in early embryos from perturbation by cis-acting activators contained within these retroelements. In TRIM28-depleted ES cells, repressive chromatin marks at ERVs are replaced by histone modifications typical of active enhancers, stimulating transcription of nearby cellular genes, notably those harboring bivalent promoters. Correspondingly, ERV-derived sequences can repress or enhance expression from an adjacent promoter in transgenic embryos depending on their TRIM28 sensitivity in ES cells. TRIM28-mediated control of ERVs is therefore crucial not just to prevent retrotransposition, but more broadly to safeguard the transcriptional dynamics of early embryos.

Publication types

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

MeSH terms

  • Animals
  • Chromatin / genetics
  • Chromatin / metabolism
  • Chromosome Mapping
  • DNA Methylation
  • Embryonic Stem Cells / cytology
  • Embryonic Stem Cells / metabolism*
  • Embryonic Stem Cells / virology
  • Endogenous Retroviruses / genetics
  • Gene Deletion
  • Gene Expression Regulation, Developmental
  • Gene Silencing
  • Genetic Loci
  • Histones / genetics
  • Histones / metabolism
  • Mice
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Promoter Regions, Genetic
  • Repressor Proteins / genetics
  • Repressor Proteins / metabolism*
  • Retroelements*
  • Sequence Analysis, RNA
  • Transcription, Genetic*
  • Tripartite Motif-Containing Protein 28
  • Up-Regulation

Substances

  • Chromatin
  • Histones
  • Nuclear Proteins
  • Repressor Proteins
  • Retroelements
  • Trim28 protein, mouse
  • Tripartite Motif-Containing Protein 28