Biochemically distinct cohesin complexes mediate positioned loops between CTCF sites and dynamic loops within chromatin domains [preprint]
UMass Chan Affiliations
Department of Biochemistry and Molecular PharmacologyProgram in Systems Biology
Document Type
PreprintPublication Date
2021-08-26Keywords
Genomicschromatin
cohesin complex
Amino Acids, Peptides, and Proteins
Genetics and Genomics
Molecular Biology
Structural Biology
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Show full item recordAbstract
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. In contrast, cohesin-dependent loops within chromatin domains and that are not anchored at CTCF sites are more resistant to RAD21 cleavage. The results show that the cohesin complex mediates loops in different ways depending on genomic context and suggests that it undergoes structural changes as it dynamically extrudes and encounters CTCF sites.Source
bioRxiv 2021.08.24.457555; doi: https://doi.org/10.1101/2021.08.24.457555. Link to preprint on bioRxiv.
DOI
10.1101/2021.08.24.457555Permanent Link to this Item
http://hdl.handle.net/20.500.14038/29900Notes
This article is a preprint. Preprints are preliminary reports of work that have not been certified by peer review.
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The copyright holder for this preprint is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY-NC-ND 4.0 International license.Distribution License
http://creativecommons.org/licenses/by-nc-nd/4.0/ae974a485f413a2113503eed53cd6c53
10.1101/2021.08.24.457555
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Except where otherwise noted, this item's license is described as The copyright holder for this preprint is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY-NC-ND 4.0 International license.