Cohesion is established during DNA replication utilising chromosome associated cohesin rings as well as those loaded de novo onto nascent DNAs
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ABSTRACT:
PROVIDER: PRJNA636349 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR11893055.fastq.gz | Fastqsanger.gz | |||
| SRR11893056.fastq.gz | Fastqsanger.gz | |||
| SRR11893057.fastq.gz | Fastqsanger.gz | |||
| SRR11893058.fastq.gz | Fastqsanger.gz | |||
| SRR11893059.fastq.gz | Fastqsanger.gz |
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Similar Datasets
Project description:Sister chromatid cohesion essential for mitotic chromosome segregation is thought to involve the co-entrapment of sister DNAs within cohesin rings. Although cohesin can load onto chromosomes throughout the cell cycle, it only builds cohesion during S phase. A key question is whether cohesion is generated by conversion of cohesin complexes associated with un-replicated DNAs ahead of replication forks into cohesive structures behind them, or from nucleoplasmic cohesin that is loaded de novo onto nascent DNAs associated with forks, a process that would be dependent on cohesin's Scc2 subunit. We show here that in S. cerevisiae, both mechanisms exist and that each requires a different set of replisome-associated proteins. Cohesion produced by cohesin conversion requires Tof1/Csm3, Ctf4 and Chl1 but not Scc2 while that created by Scc2-dependent de novo loading at replication forks requires the Ctf18-RFC complex. The association of specific replisome proteins with different types of cohesion establishment opens the way to a mechanistic understanding of an aspect of DNA replication unique to eukaryotic cells.
| S-EPMC7282809 | biostudies-literature
Project description:Cohesin is established by two parallel pathways during DNA replication. Chromosome associated cohesin is converted to cohesive structures and this depends on four protein associated with the replisome; Tof1/Csm3, Ctf4 and Chl1 (TCCC). In TCCC mutants, chromosome associated cohesin is evicted from the DNA during S phase.
2020-06-16 | GSE151551 | GEO
Project description:As predicted by the notion that sister chromatid cohesion is mediated by entrapment of sister DNAs inside cohesin rings, there is a perfect correlation between co-entrapment of circular minichromosomes and sister chromatid cohesion. In most cells where cohesin loads onto chromosomes but fails to form cohesion, loading is accompanied by entrapment of individual DNAs. However, cohesin with a hinge whose positively charged lumen has been neutralized not only loads onto and translocates along chromatin but also organizes it into chromatid-like threads, despite largely failing to entrap DNAs inside its ring. Thus, cohesin engages chromatin in both a non-topological and a topological manner. Further, mutation of three highly conserved lysines within the Smc1 hinge abolishes all loading without affecting cohesin’s initial recruitment to centromers or its ability to hydrolyze ATP. We suggest that loading and translocation are mediated by conformational changes in cohesin’s hinge driven by cycles of ATP hydrolysis.
2018-04-23 | GSE105005 | GEO
Project description:Cohesin stably holds together the sister chromatids from S phase until mitosis. To do so, cohesin must be protected against its cellular antagonist Wapl. Eco1 acetylates cohesinâs Smc3 subunit, which locks together the sister DNAs. We used yeast genetics to dissect how Wapl drives cohesin from chromatin and identified mutants of cohesin that are impaired in ATPase activity but remarkably confer robust cohesion that bypasses the need for the cohesin protectors Eco1 in yeast and Sororin in human cells. We uncover an unexpected functional asymmetry within the heart of cohesinâs highly conserved ABC-like ATPase machinery and show that an activity associated with one of cohesinâs two ATPase sites drives DNA release from cohesin rings. This key mechanism is conserved from yeast to humans. We propose that Eco1 locks cohesin rings around the sister chromatids by counteracting an asymmetric cohesin-associated ATPase activity. Effect of mutations in Smc1 and Smc3 on cohesin loading onto chromosomes
2016-02-18 | E-GEOD-76891 | biostudies-arrayexpress
Project description:In addition to extruding DNA loops, cohesin entraps within its SMC-kleisin ring (S-K) individual DNAs during G1 and sister DNAs during S-phase. All three activities require related hook-shaped proteins called Scc2 and Scc3. Using thiol-specific crosslinking we provide rigorous proof of entrapment activity in vitro. Scc2 alone promotes entrapment of DNAs in the E-S and E-K compartments, between ATP-bound engaged heads and the SMC hinge and associated kleisin, respectively. This does not require ATP hydrolysis nor is it accompanied by entrapment within S-K rings, which is a slower process requiring Scc3. Cryo-EM reveals that DNAs transported into E-S/E-K compartments are “clamped” in a sub-compartment created by Scc2’s association with engaged heads whose coiled coils are folded around their elbow. We suggest that clamping may be a recurrent feature of cohesin complexes active in loop extrusion and that this conformation precedes the S-K entrapment required for sister chromatid cohesion.
2020-09-03 | GSE156616 | GEO
Project description:Two identical sister copies of eukaryotic chromosomes are synthesised during S-phase. To facilitate their recognition as pairs for segregation in mitosis, sister chromatids are held together from their synthesis onwards by the chromosomal cohesin complex. It is thought that replication fork progression is coupled to establishment of sister chromatid cohesion, thus facilitating identification of replication products, but evidence for this has remained circumstantial. Here we show that three proteins required for sister chromatid cohesion, Eco1, Ctf4 and Ctf18 are found close to, and Ctf4 travels along chromosomes with replication forks. The ring-shaped cohesin complex is loaded onto chromosomes before S-phase in an ATP hydrolysis-dependent reaction. Cohesion establishment during DNA replication follows without further cohesin recruitment, and without need for cohesin to re-engage an ATP hydrolysis motif that is critical for its initial DNA binding. This provides evidence for cohesion establishment in the context of replication forks and imposes constraints on the mechanism involved. Keywords: ChIP on chip
2006-09-02 | GSE5719 | GEO
Project description:Cohesin stably holds together the sister chromatids from S phase until mitosis. To do so, cohesin must be protected against its cellular antagonist Wapl. Eco1 acetylates cohesin’s Smc3 subunit, which locks together the sister DNAs. We used yeast genetics to dissect how Wapl drives cohesin from chromatin and identified mutants of cohesin that are impaired in ATPase activity but remarkably confer robust cohesion that bypasses the need for the cohesin protectors Eco1 in yeast and Sororin in human cells. We uncover an unexpected functional asymmetry within the heart of cohesin’s highly conserved ABC-like ATPase machinery and show that an activity associated with one of cohesin’s two ATPase sites drives DNA release from cohesin rings. This key mechanism is conserved from yeast to humans. We propose that Eco1 locks cohesin rings around the sister chromatids by counteracting an asymmetric cohesin-associated ATPase activity.
2016-02-18 | GSE76891 | GEO
Project description:Although splicing is essential for the expression of most eukaryotic genes, inactivation of splicing factors causes specific defects in mitosis. The molecular cause of this defect is unknown. Here we show that the spliceosome subunits SNW1 and PRPF8 are essential for sister chromatid cohesion in human cells. A transcriptome-wide analysis revealed that SNW1 or PRPF8 depletion affects the splicing of specific introns in a subset of pre-mRNAs, including pre-mRNAs encoding the cohesion protein sororin and the APC/C subunit APC2. SNW1 depletion causes cohesion defects predominantly by reducing sororin levels, which causes destabilisation of cohesin on DNA. SNW1 depletion also reduces APC/C activity and contributes to cohesion defects indirectly by delaying mitosis and causing ‘cohesion fatigue’. Simultaneous expression of sororin and APC2 from intron-less cDNAs restores cohesion in SNW1 depleted cells. These results indicate that the spliceosome is required for mitosis because it enables expression of genes essential for cohesion. Our transcriptome-wide identification of retained introns in SNW1 and PRPF8 depleted cells may help to understand the aetiology of diseases associated with splicing defects, such as retinosa pigmentosum and cancer.
2016-06-29 | PXD001249 | Pride
Project description:Correct chromosome segregation requires that sister chromatids are held together by the protein complex cohesin, from S phase until anaphase. This S phase established cohesion is, together with DSB recruitment of cohesin and formation of damage induced (DI) cohesion, also important for repair of DSBs. Eco1 is a common essential factor for S phase and DI-cohesion. The fission yeast Eco1ortholog, Eso1, is important both for S phase cohesion and for bypass of UV induced lesions, and is expressed as a fusion protein with Polη. The cohesion function has been attributed solely to Eso1 and the lesion bypass function to the Polη part of the protein. As we found the interaction between the two proteins intriguing we decided to look for a functional connection also in budding yeast. Indeed, despite being dispensable for S phase cohesion, budding yeast Polη is required for formation of DI genome-wide cohesion. However, Polη deficient cells are DSB repair competent, revealing differential regulation of DI-cohesion at the break and genome-wide. This finding challenges the importance of DI genome-wide cohesion for DSB repair, and based on our findings we suggest that S phase cohesion is not sufficient for correct chromosome segregation in the presence of DNA damage.
2013-01-15 | GSE42655 | GEO