scholarly journals Multiple Determinants and Consequences of Cohesion Fatigue in Mammalian Cells

2017 ◽  
Author(s):  
Hem Sapkota ◽  
Emilia Wasiak ◽  
Gary J. Gorbsky

AbstractCells delayed in metaphase with intact mitotic spindles undergo cohesion fatigue, where sister chromatids separate asynchronously, while cells remain in M phase. Cohesion fatigue requires release of sister chromatid cohesion. However, the pathways necessary to breach sister chromatid cohesion during cohesion fatigue remain unknown. Using a regulated protein heterodimerization system to lock different cohesin interfaces at specific times in mitosis, we show that the prophase pathway of Cohesin release is not required for cohesion fatigue. By manipulating microtubule stability and Cohesin complex integrity in cell lines with varying sensitivity to cohesion fatigue, we show that rates of cohesion fatigue reflect a dynamic balance between spindle pulling forces and resistance to separation by interchromatid cohesion. Cohesion fatigue that results in complete chromatid separation may be an unrecognized but common source of chromosome instability. Here, we extend the significance of cohesion fatigue by showing that even limited delays at metaphase lead to partial centromere separation and predispose cells to chromosome missegregation.

2018 ◽  
Vol 29 (15) ◽  
pp. 1811-1824 ◽  
Author(s):  
Hem Sapkota ◽  
Emilia Wasiak ◽  
John R. Daum ◽  
Gary J. Gorbsky

Cells delayed in metaphase with intact mitotic spindles undergo cohesion fatigue, where sister chromatids separate asynchronously, while cells remain in mitosis. Cohesion fatigue requires release of sister chromatid cohesion. However, the pathways that breach sister chromatid cohesion during cohesion fatigue remain unknown. Using moderate-salt buffers to remove loosely bound chromatin cohesin, we show that “cohesive” cohesin is not released during chromatid separation during cohesion fatigue. Using a regulated protein heterodimerization system to lock different cohesin ring interfaces at specific times in mitosis, we show that the Wapl-mediated pathway of cohesin release is not required for cohesion fatigue. By manipulating microtubule stability and cohesin complex integrity in cell lines with varying sensitivity to cohesion fatigue, we show that rates of cohesion fatigue reflect a dynamic balance between spindle pulling forces and resistance to separation by interchromatid cohesion. Finally, while massive separation of chromatids in cohesion fatigue likely produces inviable cell progeny, we find that short metaphase delays, leading to partial chromatid separation, predispose cells to chromosome missegregation. Thus, complete separation of one or a few chromosomes and/or partial separation of sister chromatids may be an unrecognized but common source of chromosome instability that perpetuates the evolution of malignant cells in cancer.


2018 ◽  
Author(s):  
Yuehong Yang ◽  
Wei Wang ◽  
Min Li ◽  
Wen Zhang ◽  
Yuliang Huang ◽  
...  

AbstractSister chromatid cohesion plays a key role in ensuring precise chromosome segregation during mitosis, which is mediated by the multisubunit complex cohesin. However, the molecular regulation of cohesin subunits stability remains unclear. Here, we show that NudCL2 (NudC-like protein 2) is essential for the stability of cohesin subunits by regulating Hsp90 ATPase activity in mammalian cells. Depletion of NudCL2 induces mitotic defects and premature sister chromatid separation and destabilizes cohesin subunits that interact with NudCL2. Similar defects are also observed upon inhibition of Hsp90 ATPase activity. Interestingly, ectopic expression of Hsp90 efficiently rescues the protein instability and functional deficiency of cohesin induced by NudCL2 depletion, but not vice versa. Moreover, NudCL2 not only binds to Hsp90, but also significantly modulates Hsp90 ATPase activity and promotes the chaperone function of Hsp90. Taken together, these data suggest that NudCL2 is a previously undescribed Hsp90 cochaperone to modulate sister chromatid cohesion by stabilizing cohesin subunits, providing a hitherto unrecognized mechanism that is crucial for faithful chromosome segregation during mitosis.


2021 ◽  
Vol 22 (17) ◽  
pp. 9515
Author(s):  
Mirna R. Tenan ◽  
Adeline Nicolle ◽  
Daniela Moralli ◽  
Emeline Verbouwe ◽  
Julia D. Jankowska ◽  
...  

Chromosome instability (CIN) consists of high rates of structural and numerical chromosome abnormalities and is a well-known hallmark of cancer. Aluminum is added to many industrial products of frequent use. Yet, it has no known physiological role and is a suspected human carcinogen. Here, we show that V79 cells, a well-established model for the evaluation of candidate chemical carcinogens in regulatory toxicology, when cultured in presence of aluminum—in the form of aluminum chloride (AlCl3) and at concentrations in the range of those measured in human tissues—incorporate the metal in a dose-dependent manner, predominantly accumulating it in the perinuclear region. Intracellular aluminum accumulation rapidly leads to a dose-dependent increase in DNA double strand breaks (DSB), in chromosome numerical abnormalities (aneuploidy) and to proliferation arrest in the G2/M phase of the cell cycle. During mitosis, V79 cells exposed to aluminum assemble abnormal multipolar mitotic spindles and appear to cluster supernumerary centrosomes, possibly explaining why they accumulate chromosome segregation errors and damage. We postulate that chronic aluminum absorption favors CIN in mammalian cells, thus promoting carcinogenesis.


2006 ◽  
Vol 119 (23) ◽  
pp. 4857-4865 ◽  
Author(s):  
J. L. Parish ◽  
J. Rosa ◽  
X. Wang ◽  
J. M. Lahti ◽  
S. J. Doxsey ◽  
...  

2005 ◽  
Vol 360 (1455) ◽  
pp. 483-496 ◽  
Author(s):  
Kim Nasmyth

The sister chromatid cohesion essential for the bi-orientation of chromosomes on mitotic spindles depends on a multi-subunit complex called cohesin. This paper reviews the evidence that cohesin is directly responsible for holding sister DNAs together and considers how it might perform this function in the light of recent data on its structure.


eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Wei Zhang ◽  
Clarence Hue Lok Yeung ◽  
Liwen Wu ◽  
Karen Wing Yee Yuen

Bre1, a conserved E3 ubiquitin ligase in Saccharomyces cerevisiae, together with its interacting partner Lge1, are responsible for histone H2B monoubiquitination, which regulates transcription, DNA replication, and DNA damage response and repair, ensuring the structural integrity of the genome. Deletion of BRE1 or LGE1 also results in whole chromosome instability. We discovered a novel role for Bre1, Lge1 and H2Bub1 in chromosome segregation and sister chromatid cohesion. Bre1’s function in G1 and S phases contributes to cohesion establishment, but it is not required for cohesion maintenance in G2 phase. Bre1 is dispensable for the loading of cohesin complex to chromatin in G1, but regulates the localization of replication factor Mcm10 and cohesion establishment factors Ctf4, Ctf18 and Eco1 to early replication origins in G1 and S phases, and promotes cohesin subunit Smc3 acetylation for cohesion stabilization. H2Bub1 epigenetically marks the origins, potentially signaling the coupling of DNA replication and cohesion establishment.


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