Germline expression of mammalian CTF18, an evolutionarily conserved protein required for germ cell proliferation in the fly and sister chromatid cohesion in yeast

AbstractCohesin acetyltransferases Esco1 and Esco2 play a vital role in establishing sister chromatid cohesion. How Esco1 and Esco2 are controlled to achieve this in a DNA replication-coupled manner remains unclear in higher eukaryotes. Here we show that Cul4-RING ligases (CRL4s) play a critical role in sister chromatid cohesion in human cells. Depletion of Cul4A, Cul4B or Ddb1 subunits substantially reduces normal cohesion efficiency. We also show that Mms22L, a vertebrate ortholog of yeast Mms22, is one of Ddb1 and Cul4-associated factors (DCAFs) involved in cohesion. Several lines of evidence suggest a selective interaction of CRL4s with Esco2, but not Esco1. Depletion of either CRL4s or Esco2 causes a defect in Smc3 acetylation which can be rescued by HDAC8 inhibition. More importantly, both CRL4s and PCNA act as mediators for efficiently stabilizing Esco2 on chromatin and catalyzing Smc3 acetylation. Taken together, we propose an evolutionarily conserved mechanism in which CRL4s and PCNA regulate Esco2-dependent establishment of sister chromatid cohesion.Author summaryWe identified human Mms22L as a substrate specific adaptor of Cul4-Ddb1 E3 ubiquitin ligase. Downregulation of Cul4A, Cul4B or Ddb1 subunit causes reduction of acetylated Smc3, via interaction with Esco2 acetyltransferase, and then impairs sister chromatid cohesion in 293T cells. We found functional complementation between Cul4-Ddb1-Mms22L E3 ligase and Esco2 in Smc3 acetylation and sister chromatid cohesion. Interestingly, both Cul4-Ddb1 E3 ubiquitin ligase and PCNA contribute to Esco2 mediated Smc3 acetylation. To summarise, we demonstrated an evolutionarily conserved mechanism in which Cul4-Ddb1 E3 ubiquitin ligases and PCNA regulate Esco2-dependent establishment of sister chromatid cohesion.

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Functional Coupling between DNA Replication and Sister Chromatid Cohesion Establishment

International Journal of Molecular Sciences ◽

10.3390/ijms22062810 ◽

2021 ◽

Vol 22 (6) ◽

pp. 2810

Author(s):

Ana Boavida ◽

Diana Santos ◽

Mohammad Mahtab ◽

Francesca M. Pisani

Keyword(s):

Dna Replication ◽

Sister Chromatid ◽

Molecular Mechanisms ◽

Sister Chromatid Cohesion ◽

Functional Coupling ◽

Functional Link ◽

Chromatid Cohesion ◽

Evolutionarily Conserved ◽

Eukaryotic Organisms ◽

Replication Factors

Several lines of evidence suggest the existence in the eukaryotic cells of a tight, yet largely unexplored, connection between DNA replication and sister chromatid cohesion. Tethering of newly duplicated chromatids is mediated by cohesin, an evolutionarily conserved hetero-tetrameric protein complex that has a ring-like structure and is believed to encircle DNA. Cohesin is loaded onto chromatin in telophase/G1 and converted into a cohesive state during the subsequent S phase, a process known as cohesion establishment. Many studies have revealed that down-regulation of a number of DNA replication factors gives rise to chromosomal cohesion defects, suggesting that they play critical roles in cohesion establishment. Conversely, loss of cohesin subunits (and/or regulators) has been found to alter DNA replication fork dynamics. A critical step of the cohesion establishment process consists in cohesin acetylation, a modification accomplished by dedicated acetyltransferases that operate at the replication forks. Defects in cohesion establishment give rise to chromosome mis-segregation and aneuploidy, phenotypes frequently observed in pre-cancerous and cancerous cells. Herein, we will review our present knowledge of the molecular mechanisms underlying the functional link between DNA replication and cohesion establishment, a phenomenon that is unique to the eukaryotic organisms.

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From a single double helix to paired double helices and back

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2003.1417 ◽

2004 ◽

Vol 359 (1441) ◽

pp. 99-108 ◽

Cited By ~ 30

Author(s):

Kim Nasmyth ◽

Alexander Schleiffer

Keyword(s):

Cell Proliferation ◽

Sister Chromatid ◽

Double Helix ◽

Ring Structure ◽

Sister Chromatid Cohesion ◽

Eukaryotic Cells ◽

Sister Chromatids ◽

Double Helices ◽

Chromatid Cohesion ◽

Error Correction Mechanism

The propagation of our genomes during cell proliferation depends on the movement of sister DNA molecules produced by DNA replication to opposite sides of the cell before it divides. This feat is achieved by microtubules in eukaryotic cells but it has long remained a mystery how cells ensure that sister DNAs attach to microtubules with opposite orientations, known as amphitelic attachment. It is currently thought that sister chromatid cohesion has a crucial role. By resisting the forces exerted by microtubules, sister chromatid cohesion gives rise to tension that is thought essential for stabilizing kinetochore–microtubule attachments. Efficient amphitelic attachment is therefore achieved by an error correction mechanism that selectively eliminates connections that do not give rise to tension. Cohesion between sister chromatids is mediated by a multisubunit complex called cohesin which forms a gigantic ring structure. It has been proposed that sister DNAs are held together owing to their becoming entrapped within a single cohesin ring. Cohesion between sister chromatids is destroyed at the metaphase to anaphase transition by proteolytic cleavage of cohesin's Scc1 subunit by a thiol protease called separase, which severs the ring and thereby releases sister DNAs.

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Splicing factors control triple-negative breast cancer cell mitosis through SUN2 interaction and sororin intron retention

Journal of Experimental & Clinical Cancer Research ◽

10.1186/s13046-021-01863-4 ◽

2021 ◽

Vol 40 (1) ◽

Author(s):

Esmee Koedoot ◽

Eline van Steijn ◽

Marjolein Vermeer ◽

Román González-Prieto ◽

Alfred C. O. Vertegaal ◽

...

Keyword(s):

Breast Cancer ◽

Cell Proliferation ◽

Triple Negative Breast Cancer ◽

Sister Chromatid ◽

Triple Negative ◽

Sister Chromatid Cohesion ◽

Splicing Factors ◽

Proliferation Markers ◽

Tnbc Cell ◽

Chromatid Cohesion

Abstract Background Triple negative breast cancer (TNBC) is an aggressive subtype of breast cancer with limited therapeutic opportunities. Recently, splicing factors have gained attention as potential targets for cancer treatment. Here we systematically evaluated the role of RNA splicing factors in TNBC cell proliferation. Methods In this study, we performed an RNAi screen targeting 244 individual splicing factors to systematically evaluate their role in TNBC cell proliferation. For top candidates, mechanistic insight was gained using amongst others western blot, PCR, FACS, molecular imaging and cloning. Pulldown followed by mass spectrometry were used to determine protein-protein interactions and patient-derived RNA sequencing data was used relate splicing factor expression levels to proliferation markers. Results We identified nine splicing factors, including SNRPD2, SNRPD3 and NHP2L1, of which depletion inhibited proliferation in two TNBC cell lines by deregulation of sister chromatid cohesion (SCC) via increased sororin intron 1 retention and down-regulation of SMC1, MAU2 and ESPL1. Protein-protein interaction analysis of SNRPD2, SNRPD3 and NHP2L1 identified that seven out of the nine identified splicing factors belong to the same spliceosome complex including novel component SUN2 that was also critical for efficient sororin splicing. Finally, sororin transcript levels are highly correlated to various proliferation markers in BC patients. Conclusion We systematically determined splicing factors that control proliferation of breast cancer cells through a mechanism that involves effective sororin splicing and thereby appropriate sister chromatid cohesion. Moreover, we identified SUN2 as an important new spliceosome complex interacting protein that is critical in this process. We anticipate that deregulating sororin levels through targeting of the relevant splicing factors might be a potential strategy to treat TNBC.

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Drosophila Nipped-B Protein Supports Sister Chromatid Cohesion and Opposes the Stromalin/Scc3 Cohesion Factor To Facilitate Long-Range Activation of the cut Gene

Molecular and Cellular Biology ◽

10.1128/mcb.24.8.3100-3111.2004 ◽

2004 ◽

Vol 24 (8) ◽

pp. 3100-3111 ◽

Cited By ~ 155

Author(s):

Robert A. Rollins ◽

Maria Korom ◽

Nathalie Aulner ◽

Andrew Martens ◽

Dale Dorsett

Keyword(s):

Saccharomyces Cerevisiae ◽

Drosophila Melanogaster ◽

Long Range ◽

Sister Chromatid ◽

Transcriptional Activation ◽

Domain Boundary ◽

Sister Chromatid Cohesion ◽

Chromatin Domain ◽

Chromatid Cohesion ◽

Evolutionarily Conserved

ABSTRACT The Drosophila melanogaster Nipped-B protein facilitates transcriptional activation of the cut and Ultrabithorax genes by remote enhancers. Sequence homologues of Nipped-B, Scc2 of Saccharomyces cerevisiae, and Mis4 of Schizosaccharomyces pombe are required for sister chromatid cohesion during mitosis. The evolutionarily conserved Cohesin protein complex mediates sister chromatid cohesion, and Scc2 and Mis4 are needed for Cohesin to associate with chromosomes. Here, we show that Nipped-B is also required for sister chromatid cohesion but that, opposite to the effect of Nipped-B, the stromalin/Scc3 component of Cohesin inhibits long-range activation of cut. To explain these findings, we propose a model based on the chromatin domain boundary activities of Cohesin in which Nipped-B facilitates cut activation by alleviating Cohesin-mediated blocking of enhancer-promoter communication.

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Polo kinase Cdc5 associates with centromeres to facilitate the removal of centromeric cohesin during mitosis

Molecular Biology of the Cell ◽

10.1091/mbc.e16-01-0004 ◽

2016 ◽

Vol 27 (14) ◽

pp. 2286-2300 ◽

Cited By ~ 16

Author(s):

Prashant K. Mishra ◽

Sultan Ciftci-Yilmaz ◽

David Reynolds ◽

Wei-Chun Au ◽

Lars Boeckmann ◽

...

Keyword(s):

Chromosome Segregation ◽

Sister Chromatid ◽

Sister Chromatid Cohesion ◽

Centromeric Chromatin ◽

Polo Kinase ◽

Chromatid Cohesion ◽

Evolutionarily Conserved ◽

Sister Chromatid Separation

Sister chromatid cohesion is essential for tension-sensing mechanisms that monitor bipolar attachment of replicated chromatids in metaphase. Cohesion is mediated by the association of cohesins along the length of sister chromatid arms. In contrast, centromeric cohesin generates intrastrand cohesion and sister centromeres, while highly cohesin enriched, are separated by >800 nm at metaphase in yeast. Removal of cohesin is necessary for sister chromatid separation during anaphase, and this is regulated by evolutionarily conserved polo-like kinase (Cdc5 in yeast, Plk1 in humans). Here we address how high levels of cohesins at centromeric chromatin are removed. Cdc5 associates with centromeric chromatin and cohesin-associated regions. Maximum enrichment of Cdc5 in centromeric chromatin occurs during the metaphase-to-anaphase transition and coincides with the removal of chromosome-associated cohesin. Cdc5 interacts with cohesin in vivo, and cohesin is required for association of Cdc5 at centromeric chromatin. Cohesin removal from centromeric chromatin requires Cdc5 but removal at distal chromosomal arm sites does not. Our results define a novel role for Cdc5 in regulating removal of centromeric cohesins and faithful chromosome segregation.

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