The contribution of cohesin-SA1 to gene expression and chromatin architecture in two murine tissues

Nucleic Acids Res. 2015 Mar 31;43(6):3056-67. doi: 10.1093/nar/gkv144. Epub 2015 Mar 3.

Abstract

Cohesin, which in somatic vertebrate cells consists of SMC1, SMC3, RAD21 and either SA1 or SA2, mediates higher-order chromatin organization. To determine how cohesin contributes to the establishment of tissue-specific transcriptional programs, we compared genome-wide cohesin distribution, gene expression and chromatin architecture in cerebral cortex and pancreas from adult mice. More than one third of cohesin binding sites differ between the two tissues and these show reduced overlap with CCCTC-binding factor (CTCF) and are enriched at the regulatory regions of tissue-specific genes. Cohesin/CTCF sites at active enhancers and promoters contain, at least, cohesin-SA1. Analyses of chromatin contacts at the Protocadherin (Pcdh) and Regenerating islet-derived (Reg) gene clusters, mostly expressed in brain and pancreas, respectively, revealed remarkable differences that correlate with the presence of cohesin. We could not detect significant changes in the chromatin contacts at the Pcdh locus when comparing brains from wild-type and SA1 null embryos. In contrast, reduced dosage of SA1 altered the architecture of the Reg locus and decreased the expression of Reg genes in the pancreas of SA1 heterozygous mice. Given the role of Reg proteins in inflammation, such reduction may contribute to the increased incidence of pancreatic cancer observed in these animals.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Binding Sites
  • CCCTC-Binding Factor
  • Cadherins / genetics
  • Cell Cycle Proteins / deficiency
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism*
  • Cerebral Cortex / metabolism
  • Chromatin / chemistry
  • Chromatin / genetics
  • Chromatin / metabolism*
  • Chromosomal Proteins, Non-Histone / deficiency
  • Chromosomal Proteins, Non-Histone / genetics
  • Chromosomal Proteins, Non-Histone / metabolism*
  • Gene Expression
  • Heterozygote
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Multigene Family
  • Pancreas / metabolism
  • Protein Subunits / deficiency
  • Protein Subunits / genetics
  • Protein Subunits / metabolism
  • RNA / genetics
  • RNA / metabolism
  • Repressor Proteins / metabolism
  • Tissue Distribution

Substances

  • CCCTC-Binding Factor
  • Cadherins
  • Cell Cycle Proteins
  • Chromatin
  • Chromosomal Proteins, Non-Histone
  • Ctcf protein, mouse
  • Protein Subunits
  • Repressor Proteins
  • cohesins
  • RNA