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bioRxiv · 10.1101/166264

Distinct roles of cohesin-SA1 and cohesin-SA2 in 3D chromosome organization

Kojic, A.·Ana, C.·De Koninck, M.·Gomez-Lopez, G.·Rodriguez-Corsino, M.·Le Dily, F.·Marti-Renom, M.·Losada, A.
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Abstract

In addition to mediating sister chromatid cohesion, cohesin plays a central role in DNA looping and segmentation of the genome into contact domains (TADs). Two variant cohesin complexes that contain either STAG/SA1 or SA2 are present in all cell types. Here we addressed their specific contribution to genome architecture in non-transformed human cells. We found that cohesin-SA1 drives stacking of cohesin rings at CTCF-bound sites and thereby contributes to the stabilization and preservation of TAD boundaries. In contrast, a more dynamic cohesin-SA2 promotes cell type-specific contacts between enhancers and promoters within TADs independently of CTCF. SA2 loss, a condition frequently observed in cancer cells, results in increased intra-TAD interactions, likely altering the expression of key cell identity genes.

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Kojic, A., Ana, C., De Koninck, M., Gomez-Lopez, G., Rodriguez-Corsino, M., Le Dily, F., Marti-Renom, M., Losada, A.. 2017-07-20. Distinct roles of cohesin-SA1 and cohesin-SA2 in 3D chromosome organization. https://doi.org/10.1101/166264

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