Cohesin without cohesion: a novel role for Pds5 in Saccharomyces cerevisiae.

High fidelity chromosome segregation during mitosis requires that cells identify the products of DNA replication during S-phase and then maintain that identity until anaphase onset. Sister chromatid identity is achieved through cohesin complexes (Smc1, Smc3, and Mcd1 and Irr1/Scc3), but the structur...

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Main Authors: Kevin Tong, Robert V Skibbens
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2014-01-01
Series:PLoS ONE
Online Access:https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/24963665/pdf/?tool=EBI
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author Kevin Tong
Robert V Skibbens
author_facet Kevin Tong
Robert V Skibbens
author_sort Kevin Tong
collection DOAJ
description High fidelity chromosome segregation during mitosis requires that cells identify the products of DNA replication during S-phase and then maintain that identity until anaphase onset. Sister chromatid identity is achieved through cohesin complexes (Smc1, Smc3, and Mcd1 and Irr1/Scc3), but the structure through which cohesins perform this task remains enigmatic. In the absence of unambiguous data, a popular model is that a subset of cohesin subunits form a huge ring-like structure that embraces both sister chromatids. This 'one-ring two-sister chromatid embrace' model makes clear predictions--including that premature cohesion loss in mitotic cells must occur through a substantial reduction in cohesin-DNA associations. We used chromatin immunoprecipitation to directly test for cohesin dissociation from well-established cohesin binding sites in mitotic cells inactivated for Pds5--a key cohesin regulatory protein. The results reveal little if any chromatin dissociation from cohesins, despite a regimen that produces both massive loss of sister chromatid tethering and cell inviability. We further excluded models that cohesion loss in mitotic cells inactivated for Pds5 arises through either cohesin subunit degradation, premature Hos1-dependent Smc3 de-acetylation or Rad61/WAPL-dependent regulation of cohesin dynamics. In combination, our findings support a model that cohesin complexes associate with each sister and that sister chromatid cohesion likely results from cohesin-cohesin interactions. We further assessed the role that Pds5 plays in cohesion establishment during S-phase. The results show that Pds5 inactivation can result in establishment defects despite normal cohesion loading and Smc3 acetylation, revealing a novel establishment role for Pds5 that is independent of these processes. The combination of findings provides important new insights that significantly impact current models of both cohesion establishment reactions and maintenance.
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spelling doaj.art-4b2552c4fc24474ba2126773bcaf66b72022-12-21T16:58:42ZengPublic Library of Science (PLoS)PLoS ONE1932-62032014-01-0196e10047010.1371/journal.pone.0100470Cohesin without cohesion: a novel role for Pds5 in Saccharomyces cerevisiae.Kevin TongRobert V SkibbensHigh fidelity chromosome segregation during mitosis requires that cells identify the products of DNA replication during S-phase and then maintain that identity until anaphase onset. Sister chromatid identity is achieved through cohesin complexes (Smc1, Smc3, and Mcd1 and Irr1/Scc3), but the structure through which cohesins perform this task remains enigmatic. In the absence of unambiguous data, a popular model is that a subset of cohesin subunits form a huge ring-like structure that embraces both sister chromatids. This 'one-ring two-sister chromatid embrace' model makes clear predictions--including that premature cohesion loss in mitotic cells must occur through a substantial reduction in cohesin-DNA associations. We used chromatin immunoprecipitation to directly test for cohesin dissociation from well-established cohesin binding sites in mitotic cells inactivated for Pds5--a key cohesin regulatory protein. The results reveal little if any chromatin dissociation from cohesins, despite a regimen that produces both massive loss of sister chromatid tethering and cell inviability. We further excluded models that cohesion loss in mitotic cells inactivated for Pds5 arises through either cohesin subunit degradation, premature Hos1-dependent Smc3 de-acetylation or Rad61/WAPL-dependent regulation of cohesin dynamics. In combination, our findings support a model that cohesin complexes associate with each sister and that sister chromatid cohesion likely results from cohesin-cohesin interactions. We further assessed the role that Pds5 plays in cohesion establishment during S-phase. The results show that Pds5 inactivation can result in establishment defects despite normal cohesion loading and Smc3 acetylation, revealing a novel establishment role for Pds5 that is independent of these processes. The combination of findings provides important new insights that significantly impact current models of both cohesion establishment reactions and maintenance.https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/24963665/pdf/?tool=EBI
spellingShingle Kevin Tong
Robert V Skibbens
Cohesin without cohesion: a novel role for Pds5 in Saccharomyces cerevisiae.
PLoS ONE
title Cohesin without cohesion: a novel role for Pds5 in Saccharomyces cerevisiae.
title_full Cohesin without cohesion: a novel role for Pds5 in Saccharomyces cerevisiae.
title_fullStr Cohesin without cohesion: a novel role for Pds5 in Saccharomyces cerevisiae.
title_full_unstemmed Cohesin without cohesion: a novel role for Pds5 in Saccharomyces cerevisiae.
title_short Cohesin without cohesion: a novel role for Pds5 in Saccharomyces cerevisiae.
title_sort cohesin without cohesion a novel role for pds5 in saccharomyces cerevisiae
url https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/24963665/pdf/?tool=EBI
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AT robertvskibbens cohesinwithoutcohesionanovelroleforpds5insaccharomycescerevisiae