HSA21 Single-Minded 2 (Sim2) Binding Sites Co-Localize with Super-Enhancers and Pioneer Transcription Factors in Pluripotent Mouse ES Cells

PLoS One. 2015 May 8;10(5):e0126475. doi: 10.1371/journal.pone.0126475. eCollection 2015.

Abstract

The HSA21 encoded Single-minded 2 (SIM2) transcription factor has key neurological functions and is a good candidate to be involved in the cognitive impairment of Down syndrome. We aimed to explore the functional capacity of SIM2 by mapping its DNA binding sites in mouse embryonic stem cells. ChIP-sequencing revealed 1229 high-confidence SIM2-binding sites. Analysis of the SIM2 target genes confirmed the importance of SIM2 in developmental and neuronal processes and indicated that SIM2 may be a master transcription regulator. Indeed, SIM2 DNA binding sites share sequence specificity and overlapping domains of occupancy with master transcription factors such as SOX2, OCT4 (Pou5f1), NANOG or KLF4. The association between SIM2 and these pioneer factors is supported by co-immunoprecipitation of SIM2 with SOX2, OCT4, NANOG or KLF4. Furthermore, the binding of SIM2 marks a particular sub-category of enhancers known as super-enhancers. These regions are characterized by typical DNA modifications and Mediator co-occupancy (MED1 and MED12). Altogether, we provide evidence that SIM2 binds a specific set of enhancer elements thus explaining how SIM2 can regulate its gene network in neuronal features.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Basic Helix-Loop-Helix Transcription Factors / metabolism*
  • Binding Sites
  • Cells, Cultured
  • Chromatin Immunoprecipitation / methods
  • DNA / genetics
  • DNA / metabolism*
  • Enhancer Elements, Genetic*
  • Kruppel-Like Factor 4
  • Mice
  • Mouse Embryonic Stem Cells / metabolism*
  • Sequence Analysis, RNA
  • Transcription Factors / genetics*
  • Transcription Factors / metabolism

Substances

  • Basic Helix-Loop-Helix Transcription Factors
  • Klf4 protein, mouse
  • Kruppel-Like Factor 4
  • Sim2 protein, mouse
  • Transcription Factors
  • DNA

Associated data

  • GEO/GSE59379

Grants and funding

This work was supported by grants from the Swiss National Science Foundation, and the European ERC to SEA, and the Lejeune Foundation to CB. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.