CTCF-CTCF loops and intra-TAD interactions show differential dependence on cohesin ring integrity.

ABSTRACT: The ring-like cohesin complex mediates sister-chromatid cohesion by encircling pairs of sister chromatids. Cohesin also extrudes loops along chromatids. Whether the two activities involve similar mechanisms of DNA engagement is not known. We implemented an experimental approach based on isolated nuclei carrying engineered cleavable RAD21 proteins to precisely control cohesin ring integrity so that its role in chromatin looping could be studied under defined experimental conditions. This approach allowed us to identify cohesin complexes with distinct biochemical, and possibly structural, properties that mediate different sets of chromatin loops. When RAD21 is cleaved and the cohesin ring is opened, cohesin complexes at CTCF sites are released from DNA and loops at these elements are lost. I

SUBMITTER: Liu Y 

PROVIDER: S-EPMC10174090 | biostudies-literature | 2022 Oct

REPOSITORIES: biostudies-literature