Pds5 promotes and protects cohesin acetylation

The cohesin complex links DNA molecules and plays key roles in the organization, expression, repair, and segregation of eukaryotic genomes. In vertebrates the Esco1 and Esco2 acetyltransferases both modify cohesin's Smc3 subunit to establish sister chromatid cohesion during S phase, but differ in their N-terminal domains and expression during development and across the cell cycle. Here we show that Esco1 and Esco2 also differ dramatically in their interaction with chromatin, as Esco1 is recruited by cohesin to over 11,000 sites, whereas Esco2 is infrequently enriched at REST/NRSF target genes. Esco1's colocalization with cohesin occurs throughout the cell cycle and depends on two short motifs (the A-box and B-box) present in and unique to all Esco1 orthologs. Deleting either motif led to the derepression of Esco1-proximal genes and functional uncoupling of cohesion from Smc3 acetylation. In contrast, other mutations that preserved Esco1's recruitment separated its roles in cohesion establishment and gene silencing. We conclude that Esco1 uses cohesin as both a substrate and a scaffold for coordinating multiple chromatinbased transactions in somatic cells. mitosis | gene expression | sister chromatids | chromosomes | acetylation

Section: Discussionmentioning

confidence: 85%

Cohesin recruits the Esco1 acetyltransferase genome wide to repress transcription and promote cohesion in somatic cells

Rahman

Jallepalli

2015

“…Both Scc3 and Pds5 are Scc1-binding proteins, and they bind to different regions of Scc1 (8,9,27,(35)(36)(37). Scc3 binds to the middle region of Scc1, whereas Pds5 binds to a region immediately adjacent to the NHD.…”

Section: Resultsmentioning

confidence: 99%

“…Although binding of Pds5 to cohesin does not require Smc3 acetylation in human cells, the Pds5-dependent binding of sororin to cohesin requires Smc3 acetylation (27). In the budding yeast, Pds5 protects cohesin from deacetylation and turns over more rapidly on pericentric chromatin in cells lacking Eco1 (37,42), suggesting that Pds5 might interact with acetylated Smc3 in that organism. Thus, Smc3 acetylation and subsequent binding of Pds5 (Pds5-sororin interaction in vertebrates) might actively promote the release of Scc2 from loaded cohesin, freeing it to perform additional rounds of cohesin loading (Fig.…”

Section: Discussionmentioning

confidence: 99%

Crystal structure of the cohesin loader Scc2 and insight into cohesinopathy

Kikuchi

Borek

Otwinowski

et al. 2016

113

125

The ring-shaped cohesin complex topologically entraps chromosomes and regulates chromosome segregation, transcription, and DNA repair. The cohesin core consists of the structural maintenance of chromosomes 1 and 3 (Smc1-Smc3) heterodimeric ATPase, the kleisin subunit sister chromatid cohesion 1 (Scc1) that links the two ATPase heads, and the Scc1-bound adaptor protein Scc3. The sister chromatid cohesion 2 and 4 (Scc2-Scc4) complex loads cohesin onto chromosomes. Mutations of cohesin and its regulators, including Scc2, cause human developmental diseases termed cohesinopathy. Here, we report the crystal structure of Chaetomium thermophilum (Ct) Scc2 and examine its interaction with cohesin. Similar to Scc3 and another Scc1-interacting cohesin regulator, precocious dissociation of sisters 5 (Pds5), Scc2 consists mostly of helical repeats that fold into a hook-shaped structure. Scc2 binds to Scc1 through an N-terminal region of Scc1 that overlaps with its Pds5-binding region. Many cohesinopathy mutations target conserved residues in Scc2 and diminish Ct Scc2 binding to Ct Scc1. Pds5 binding to Scc1 weakens the Scc2-Scc1 interaction. Our study defines a functionally important interaction between the kleisin subunit of cohesin and the hook of Scc2. Through competing with Scc2 for Scc1 binding, Pds5 might contribute to the release of Scc2 from loaded cohesin, freeing Scc2 for additional rounds of loading.transcription | cohesinopathy | X-ray crystallography | cohesin loading | HEAT repeat C ohesin consists of four core subunits: structural maintenance of chromosomes 1 and 3 (Smc1 and Smc3), and sister chromatid cohesion 1 and 3 (Scc1 and Scc3). (1-5). Smc1 and Smc3 are related ATPases that heterodimerize through their hinge domains. The C-terminal winged helix domain and the N-terminal helical domain (NHD) of Scc1 bind to the Smc1 ATPase head and a coiled-coil segment adjacent to the Smc3 ATPase head, respectively, forming a tripartite ring (6, 7). Scc3 contains Huntingtin-elongation factor 3-protein phosphatase 2A-TOR1 (HEAT) repeats, binds to the middle region of Scc1, and provides a landing pad for several cohesin regulators (8, 9). Cohesin can topologically trap DNA inside its ring (10), thereby regulating many facets of chromosome biology. During interphase, cohesin mediates the formation of chromosome loops that impact transcription (11). During S phase, cohesin physically links replicated chromosomes to establish sister-chromatid cohesion (12, 13), which is a prerequisite for faithful chromosome segregation during mitosis. Finally, cohesin contributes to homologydirected repair of DNA breaks, in part, through holding the sister chromatid in proximity of the breaks and presenting it as the repair template (14).For cohesin to accomplish these diverse tasks, its association with chromosomes has to be tightly controlled both spatially and temporally. Cohesin dynamics on chromosomes are regulated by a set of accessory proteins, including the Scc2-Scc4 loading complex and the releasing complex comprising Pds5 and wing...

“…The mechanisms, however, through which either rescues ctf7/eco1 mutant cell conditional growth remains elusive. pds5 alleles have proved tremendously informative given their differential impact on cohesin deposition, cohesion establishment and maintenance, and also transcription, placing Pds5 at a convergence of cohesin-related developmental defects and cancers (9,11,(23)(24)(25)(26)(27)(28)(29)(30)(31). Our laboratory previously reported that ELG1 deletion suppresses pds5-1 mutant cell conditional growth, providing an important platform from which to initiate an effort to dissect and isolate various roles for Pds5 in cohesin pathways (32).…”

mentioning

confidence: 99%

Pds5 regulators segregate cohesion and condensation pathways in Saccharomyces cerevisiae

Tong

Skibbens

2015

Cohesins are required both for the tethering together of sister chromatids (termed cohesion) and subsequent condensation into discrete structures-processes fundamental for faithful chromosome segregation into daughter cells. Differentiating between cohesin roles in cohesion and condensation would provide an important advance in studying chromatin metabolism. Pds5 is a cohesin-associated factor that is essential for both cohesion maintenance and condensation. Recent studies revealed that ELG1 deletion suppresses the temperature sensitivity of pds5 mutant cells. However, the mechanisms through which Elg1 may regulate cohesion and condensation remain unknown. Here, we report that ELG1 deletion from pds5-1 mutant cells results in a significant rescue of cohesion, but not condensation, defects. Based on evidence that Elg1 unloads the DNA replication clamp PCNA from DNA, we tested whether PCNA overexpression would similarly rescue pds5-1 mutant cell cohesion defects. The results indeed reveal that elevated levels of PCNA rescue pds5-1 temperature sensitivity and cohesion defects, but do not rescue pds5-1 mutant cell condensation defects. In contrast, RAD61 deletion rescues the condensation defect, but importantly, neither the temperature sensitivity nor cohesion defects exhibited by pds5-1 mutant cells. In combination, these findings reveal that cohesion and condensation are separable pathways and regulated in nonredundant mechanisms. These results are discussed in terms of a new model through which cohesion and condensation are spatially regulated.