Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Transport of DNA within cohesin involves clamping on top of engaged heads by Scc2 and entrapment within the ring by Scc3

ABSTRACT: 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.

ORGANISM(S): Saccharomyces cerevisiae Nakaseomyces glabratus

PROVIDER: GSE156616 | GEO | 2020/09/03

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Crosslinking/mass spectrometry (CLMS) analysis of Cohesin complex

2020-08-04 | PXD018608 | Pride

Releasing activity disengages cohesinâs Smc3/Scc1 interface in a process blocked by acetylation

Project description:Sister chromatid cohesion conferred by entrapment of sister DNAs within a tripartite ring formed between cohesinâs Scc1, Smc1, and Smc3 subunits is generated during S and eventually destroyed at anaphase through cleavage of Scc1 by separase. Throughout the cell cycle, cohesinâs association with chromosomes is controlled by opposing activities: loading by the Scc2/4 complex and release by a separase independent releasing activity. Co-entrapment of sister DNAs during replication is accompanied by acetylation of Smc3 by Eco1, which blocks releasing activity and ensures that sisters remain stably connected. Because fusion of Smc3 to Scc1 prevents release and bypasses the requirement for Eco1, we suggested that release is mediated by disengagement of the Smc3/Scc1 interface. We now show that all mutations capable of bypassing Eco1, be they in cohesinâs Smc1, Smc3, Scc1,Wapl, Pds5, or Scc3 subunits, greatly reduce dissociation of N-terminal cleavage fragments of Scc1 (NScc1) from Smc3. We show that this process involves interaction between Smc ATPase heads and is inhibited by Smc3 acetylation Effect of mutations QQ and EQ in Smc3 on cohesin loading onto chromosomes

2016-02-18 | E-GEOD-76890 | biostudies-arrayexpress

A Structure-Based Mechanism for DNA Entry into the Cohesin Ring

Project description:The ring-shaped cohesin complex is thought to fulfil its roles in sister chromatid cohesion, genome stability and gene regulation by topologically encircling DNAs. The ring is formed by two Structural Maintenance of Chromosome (SMC) subunits, whose ATPase heads are linked by a kleisin subunit. Additional components, including the Mis4Scc2/NIPL cohesin loader, engage the kleisin. Here, we visualize a DNA gripping intermediate during cohesin loading onto DNA by cryo-electron microscopy. ATP-dependent head engagement creates an interaction surface onto which Mis4Scc2/NIPL clamps the DNA. We use biophysical tools to establish the order of events during cohesin loading. DNA first traverses an N-terminal kleisin gate that was opened by ATP binding and closed again as the loader locks the DNA. Ensuing ATP hydrolysis and head disengagement, assisted by Mis4Scc2/NIPL, will complete DNA entry. A conserved kleisin N-terminal tail guides the DNA on its trajectory to successful topological DNA entry into the cohesin ring.

2020-08-05 | PXD018600 | Pride

Releasing activity disengages cohesin’s Smc3/Scc1 interface in a process blocked by acetylation

Project description:Sister chromatid cohesion conferred by entrapment of sister DNAs within a tripartite ring formed between cohesin’s Scc1, Smc1, and Smc3 subunits is generated during S and eventually destroyed at anaphase through cleavage of Scc1 by separase. Throughout the cell cycle, cohesin’s association with chromosomes is controlled by opposing activities: loading by the Scc2/4 complex and release by a separase independent releasing activity. Co-entrapment of sister DNAs during replication is accompanied by acetylation of Smc3 by Eco1, which blocks releasing activity and ensures that sisters remain stably connected. Because fusion of Smc3 to Scc1 prevents release and bypasses the requirement for Eco1, we suggested that release is mediated by disengagement of the Smc3/Scc1 interface. We now show that all mutations capable of bypassing Eco1, be they in cohesin’s Smc1, Smc3, Scc1,Wapl, Pds5, or Scc3 subunits, greatly reduce dissociation of N-terminal cleavage fragments of Scc1 (NScc1) from Smc3. We show that this process involves interaction between Smc ATPase heads and is inhibited by Smc3 acetylation

2016-02-18 | GSE76890 | GEO

A folded conformation of MukBEF and Cohesin

Project description:Structural maintenance of chromosomes (SMC)-kleisin complexes organize chromosomal DNAs in all domains of life, where they have key roles in chromosome segregation, DNA repair and regulation of gene expression. They function through topological entrapment and active translocation of DNA, but the underlying conformational changes are largely unclear. Using structural biology, mass spectrometry and cross-linking, we investigated the architecture of two evolutionarily distant SMC-kleisin complexes: proteobacterial MukBEF and eukaryotic cohesin. We show that both contain a dynamic coiled-coil discontinuity, the elbow, near the middle of their arms that permits a folded conformation. Bending at the elbow brings into proximity the hinge dimerization domain and the head/kleisin module, situated at opposite ends of the arms. Our findings favor SMC activity models that include a large conformational change in the arms, such as a relative movement between DNA binding sites during DNA loading and translocation

2019-03-01 | PXD012377 | Pride

A folded conformation of MukBEF and Cohesin

Project description:PleasStructural maintenance of chromosomes (SMC)-kleisin complexes organize chromosomal DNAs in all domains of life, where they have key roles in chromosome segregation, DNA repair and regulation of gene expression. They function through topological entrapment and active translocation of DNA, but the underlying conformational changes are largely unclear. Using structural biology, mass spectrometry and cross-linking, we investigated the architecture of two evolutionarily distant SMC-kleisin complexes: proteobacterial MukBEF and eukaryotic cohesin. We show that both contain a dynamic coiled-coil discontinuity, the elbow, near the middle of their arms that permits a folded conformation. Bending at the elbow brings into proximity the hinge dimerization domain and the head/kleisin module, situated at opposite ends of the arms. Our findings favor SMC activity models that include a large conformational change in the arms, such as a relative movement between DNA binding sites during DNA loading and translocatione provide an overall description of your study, think something similar in scope to the manuscript abstract

2019-03-01 | PXD012370 | Pride

The cohesin ring uses its hinge to organize DNA using non-topological as well as topological mechanisms

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

Isw1 contributes to cohesin association with centromeres and pericentromeric regions

Project description:Cohesin is a highly conserved, multiprotein complex whose canonical function is to hold sister chromatids together to ensure accurate chromosome segregation. Cohesin association with chromatin relies on the separate Scc2-Scc4 complex that enables cohesin ring opening and topological entrapment of sister DNAs. Cohesin loading at centromeres also requires the CTF19 kinetochore subcomplex that recruits Scc2-Scc4, ensuring efficient and targeted cohesin binding. After loading at centromeres, cohesin rapidly translocates to neighboring pericentromeric regions. In an attempt to better understand how sister chromatid cohesion is regulated, we performed a proteomic screen in budding yeast that identified the Isw1 chromatin remodeler as a cohesin binding partner. We found that while cohesin can associate with both Isw1-containing complexes, ISW1a and ISW1b, however only ISW1a localizes to centromeres. There, ISW1a utilizes its chromatin remodeling activity to allow efficient translocation of cohesin loaded through CTF19 at centromeres to pericentromeres. Consistently, lack of Isw1 results in cohesin and cohesin loader retainment at CENs and periCENs. Interestingly, lack of Isw1 resulted in changes in the nucleosomal landscape at the CENs and pericentromeric regions, suggesting that chromatin organization may be a crucial determinant of cohesin loading. Finally, we provide evidence that the role of ISW1a at the CENs is to restrict the activity of the RSC complex. Taken together, our results support the notion of a key role of chromatin environment for cohesin functions.

2023-05-16 | GSE232315 | GEO

Conformational dynamics of cohesin/Scc2 loading complex are regulated by Smc3 acetylation and ATP association

Project description:The ring-shaped cohesin complex is the key player in sister chromatid cohesion, DNA repair, and gene transcription. The loading of cohesin to chromosomes requires the loader Scc2 and is regulated by ATP. This process is also hindered by Smc3 acetylation. However, the molecular mechanism behind this inhibition remains mysterious. Here we identify a novel configuration of Scc2 with pre-engaged cohesin and reveal dynamic conformations of the cohesin/Scc2 complex in the loading reaction. We demonstrate that Smc3 acetylation blocks the association of Scc2 with pre-engaged cohesin by impairing the interaction of Scc2 with Smc3’s head. Lastly, we show that ATP binding induces the cohesin/Scc2 complex to clamp DNA by promoting the interaction between Scc2 and Smc3 coiled-coil. Our results illuminate a dynamic reconfiguration of the cohesin/Scc2 complex during loading and indicate how Smc3 acetylation and ATP regulate this process.

2023-08-16 | GSE217833 | GEO

Transport of DNA within cohesin involves clamping on top of engaged heads by Scc2 and entrapment within the ring by Scc3

Project description:Transport of DNA within cohesin involves clamping on top of engaged heads by Scc2 and entrapment within the ring by Scc3

| PRJNA658519 | ENA