The contribution of cohesin-SA1 to gene expression and chromatin architecture in two murine tissues.
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.
Chromosome Dynamics Group, Molecular Oncology Programme, Spanish National Cancer Research Centre (CNIO), Melchor Fernández Almagro 3, 28029 Madrid, Spain.
Ana
A
Cuadrado
Chromosome Dynamics Group, Molecular Oncology Programme, Spanish National Cancer Research Centre (CNIO), Melchor Fernández Almagro 3, 28029 Madrid, Spain.
Silvia
S
Remeseiro
Bioinformatics Unit, Structural Biology and Biocomputing Programme, Spanish National Cancer Research Centre (CNIO), Melchor Fernández Almagro 3, 28029 Madrid, Spain.
Osvaldo
O
Graña
Bioinformatics Unit, Structural Biology and Biocomputing Programme, Spanish National Cancer Research Centre (CNIO), Melchor Fernández Almagro 3, 28029 Madrid, Spain.
David G
DG
Pisano
Chromosome Dynamics Group, Molecular Oncology Programme, Spanish National Cancer Research Centre (CNIO), Melchor Fernández Almagro 3, 28029 Madrid, Spain alosada@cnio.es.
Ana
http://orcid.org/0000-0001-5251-3383
A
Losada
D000818:Animals; D001665:Binding Sites; D000076246:CCCTC-Binding Factor; D015820:Cadherins / Q000235:genetics; D018797:Cell Cycle Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D002540:Cerebral Cortex / Q000378:metabolism; D002843:Chromatin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002868:Chromosomal Proteins, Non-Histone / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D006579:Heterozygote; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D005810:Multigene Family; D010179:Pancreas / Q000378:metabolism; D021122:Protein Subunits / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D012313:RNA / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism; D014018:Tissue Distribution; D000097722:Cohesins
D000076246:CCCTC-Binding Factor; D015820:Cadherins; D018797:Cell Cycle Proteins; D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D021122:Protein Subunits; D012313:RNA; D012097:Repressor Proteins; D000097722:Cohesins; C000619698:Ctcf protein, mouse