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Kim Nasmyth - One of the best experts on this subject based on the ideXlab platform.
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sister dna entrapment between juxtaposed smc heads and kleisin of the cohesin complex
Molecular Cell, 2019Co-Authors: Christophe Chapard, Johanna C Scheinost, Robert Jones, Till Van Oepen, Kim NasmythAbstract:Cohesin entraps sister DNAs within tripartite rings created by pairwise interactions between Smc1, SMC3, and Scc1. Because Smc1/3 ATPase heads can also interact with each other, cohesin rings have the potential to form a variety of sub-compartments. Using in vivo cysteine cross-linking, we show that when Smc1 and SMC3 ATPases are engaged in the presence of ATP (E heads), cohesin rings generate a “SMC (S) compartment” between hinge and E heads and a “kleisin (K) compartment” between E heads and their associated kleisin subunit. Upon ATP hydrolysis, cohesin’s heads associate in a different mode, in which their signature motifs and their coiled coils are closely juxtaposed (J heads), creating alternative S and K compartments. We show that K compartments of either E or J type can entrap single DNAs, that acetylation of SMC3 during S phase is associated with J heads, and that sister DNAs are entrapped in J-K compartments.
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the topology of dna entrapment by cohesin rings
bioRxiv, 2018Co-Authors: Christophe Chapard, Johanna C Scheinost, Robert Jones, Till Van Oepen, Kim NasmythAbstract:Summary Cohesin entraps sister DNAs within tripartite rings created by pairwise interactions between Smc1,SMC3, and Scc1. Because the ATPase heads of Smc1 and SMC3 can interact with each other, cohesin rings in fact have the potential to form a variety of sub-compartments. Using in vivo cysteine crosslinking,we show that when Smc1 and SMC3 ATPases are engaged in the presence of ATP (E heads)cohesin rings generate a “SMC (S) compartment” between hinge and E heads and a “kleisin (K)compartment” between E heads and their associated kleisin subunit. Upon ATP hydrolysis, cohesin’s heads associate with each other in a very different mode, in which their signature motifs and their coiled coils are closely juxtaposed (J heads), creating alternative S and K compartments. We show that all four sub-compartments exist in vivo, that acetylation of SMC3 during S phase is accompanied by an increase in the ratio of J to E heads, and that sister DNAs are entrapped in J-K but not E-K compartments or in either type of S compartment.
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S1Supplemental Data ATP Hydrolysis Is Required for Cohesin’s Association with Chromosomes
2015Co-Authors: Prakash Arumugam, Stephan Gruber, Christian H. Haering, Koichi Tanaka, Karl Mechtler, Kim NasmythAbstract:The Smc1 ATP Hydrolysis Mutant Forms Rings mutation of Scc2 and ATP hydrolysis mutants appear therefore to be similar if not identical; namely, a failure not to form tripartite ringsWe tested the effect of an smc1 mutation predicted to abolish ATP hydrolysis (E1158Q) on the formation of tripartite cohesin rings. To but to load them onto chromosomes. do this, we prepared soluble extracts from cycling cells expressing either wild-type or ATP hydrolysis mutant E1158Q myc-tagged Supplemental Experimental Procedures Smc1 and a functional TEV cleavable Scc1 that has six and three HA epitopes fused at its N and C termini (HA6-Scc1TEV-HA3), respec- Yeast Strains tively, and immunoprecipitated Smc1 by using an antibody against All strains are derivatives of W303. Genotypes used in the individual its myc9 epitope. Aliquots of the immunoprecipitation beads were experiments are given in the figure legends. All genes/markers are incubated in the presence or absence of TEV protease, and proteins as in W303 unless otherwise stated. released into the supernatant (S) were separated from those bound to the beads (B). Copurification of Scc1 with Smc1 was completely Molecular Biology dependent on the tag on Smc1 (Figure S1). N- and C-terminal Scc1 The Smc1 and SMC3 genes were cloned into yeast integrative plas-cleavage fragments remained bound to the beads after TEV cleav- mids YIplac211 and YIplac128, respectively [S3]. Mutations were age in the case of both wild-type Smc1 and its E1158Q hydrolysis introduced by overlap extension PCR. The sequences of the primer
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closing the cohesin ring structure and function of its SMC3 kleisin interface
Science, 2014Co-Authors: Thomas G Gligoris, Kim Nasmyth, Johanna C Scheinost, Frank Burmann, Naomi J Petela, Koklung Chan, Pelin Uluocak, Frederic Beckouet, Stephan Gruber, Jan LoweAbstract:Through their association with a kleisin subunit (Scc1), cohesin’s Smc1 and SMC3 subunits are thought to form tripartite rings that mediate sister chromatid cohesion. Unlike the structure of Smc1/SMC3 and Smc1/Scc1 interfaces, that of SMC3/Scc1 is not known. Disconnection of this interface is thought to release cohesin from chromosomes in a process regulated by acetylation. We show here that the N-terminal domain of yeast Scc1 contains two α helices, forming a four-helix bundle with the coiled coil emerging from SMC3’s adenosine triphosphatase head. Mutations affecting this interaction compromise cohesin’s association with chromosomes. The interface is far from SMC3 residues, whose acetylation prevents cohesin’s dissociation from chromosomes. Cohesin complexes holding chromatids together in vivo do indeed have the configuration of hetero-trimeric rings, and sister DNAs are entrapped within these.
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disengaging the SMC3 kleisin interface releases cohesin from drosophila chromosomes during interphase and mitosis
The EMBO Journal, 2013Co-Authors: Christian S Eichinger, Alexander Kurze, Raquel A Oliveira, Kim NasmythAbstract:Cohesin's Smc1, SMC3, and kleisin subunits create a tripartite ring within which sister DNAs are entrapped. Evidence suggests that DNA enters through a gate created by transient dissociation of the Smc1/3 interface. Release at the onset of anaphase is triggered by proteolytic cleavage of kleisin. Less well understood is the mechanism of release at other stages of the cell cycle, in particular during prophase when most cohesin dissociates from chromosome arms in a process dependent on the regulatory subunit Wapl. We show here that Wapl-dependent release from salivary gland polytene chromosomes during interphase and from neuroblast chromosome arms during prophase is blocked by translational fusion of SMC3's C-terminus to kleisin's N-terminus. Our findings imply that proteolysis-independent release of cohesin from chromatin is mediated by Wapl-dependent escape of DNAs through a gate created by transient dissociation of the SMC3/kleisin interface. Thus, cohesin's DNA entry and exit gates are distinct.
Frederic Beckouet - One of the best experts on this subject based on the ideXlab platform.
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releasing activity disengages cohesin s SMC3 scc1 interface in a process blocked by acetylation
Molecular Cell, 2016Co-Authors: Thomas G Gligoris, Johanna C Scheinost, Naomi J Petela, Koklung Chan, Frederic Beckouet, Maurici B Roig, Madhusudhan Srinivasan, Paul Batty, Alexandra C SmithAbstract:Sister chromatid cohesion conferred by entrapment of sister DNAs within a tripartite ring formed between cohesin’s Scc1, Smc1, and SMC3 subunits is created during S and destroyed at anaphase through Scc1 cleavage by separase. Cohesin’s association with chromosomes is controlled by opposing activities: loading by Scc2/4 complex and release by a separase-independent releasing activity as well as by cleavage. Coentrapment of sister DNAs at replication is accompanied by acetylation of SMC3 by Eco1, which blocks releasing activity and ensures that sisters remain 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 show that mutations capable of bypassing Eco1 in Smc1, SMC3, Scc1, Wapl, Pds5, and Scc3 subunits reduce dissociation of N-terminal cleavage fragments of Scc1 (NScc1) from SMC3. This process involves interaction between Smc ATPase heads and is inhibited by SMC3 acetylation.
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closing the cohesin ring structure and function of its SMC3 kleisin interface
Science, 2014Co-Authors: Thomas G Gligoris, Kim Nasmyth, Johanna C Scheinost, Frank Burmann, Naomi J Petela, Koklung Chan, Pelin Uluocak, Frederic Beckouet, Stephan Gruber, Jan LoweAbstract:Through their association with a kleisin subunit (Scc1), cohesin’s Smc1 and SMC3 subunits are thought to form tripartite rings that mediate sister chromatid cohesion. Unlike the structure of Smc1/SMC3 and Smc1/Scc1 interfaces, that of SMC3/Scc1 is not known. Disconnection of this interface is thought to release cohesin from chromosomes in a process regulated by acetylation. We show here that the N-terminal domain of yeast Scc1 contains two α helices, forming a four-helix bundle with the coiled coil emerging from SMC3’s adenosine triphosphatase head. Mutations affecting this interaction compromise cohesin’s association with chromosomes. The interface is far from SMC3 residues, whose acetylation prevents cohesin’s dissociation from chromosomes. Cohesin complexes holding chromatids together in vivo do indeed have the configuration of hetero-trimeric rings, and sister DNAs are entrapped within these.
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cohesin s dna exit gate is distinct from its entrance gate and is regulated by acetylation
Cell, 2012Co-Authors: Koklung Chan, Frederic Beckouet, Maurici B Roig, Jean Metson, Kim NasmythAbstract:Sister chromatid cohesion is mediated by entrapment of sister DNAs by a tripartite ring composed of cohesin’s Smc1, SMC3, and α-kleisin subunits. Cohesion requires acetylation of SMC3 by Eco1, whose role is to counteract an inhibitory (antiestablishment) activity associated with cohesin’s Wapl subunit. We show that mutations abrogating antiestablishment activity also reduce turnover of cohesin on pericentric chromatin. Our results reveal a “releasing” activity inherent to cohesin complexes transiently associated with Wapl that catalyzes their dissociation from chromosomes. Fusion of SMC3’s nucleotide binding domain to α-kleisin’s N-terminal domain also reduces cohesin turnover within pericentric chromatin and permits establishment of Wapl-resistant cohesion in the absence of Eco1. We suggest that releasing activity opens the SMC3/α-kleisin interface, creating a DNA exit gate distinct from its proposed entry gate at the Smc1/3 interface. According to this notion, the function of SMC3 acetylation is to block its dissociation from α-kleisin. The functional implications of regulated ring opening are discussed.
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an SMC3 acetylation cycle is essential for establishment of sister chromatid cohesion
Molecular Cell, 2010Co-Authors: Frederic Beckouet, Makiko Komata, Katsuhiko Shirahige, Pelin Uluocak, Bin Hu, Maurici B Roig, Takashi Sutani, Vittorio L Katis, Kim NasmythAbstract:Sister chromatid cohesion is thought to involve entrapment of sister DNAs by a tripartite ring composed of the cohesin subunits Smc1, SMC3, and Scc1. Establishment of cohesion during S phase depends on acetylation of SMC3's nucleotide-binding domain (NBD) by the Eco1 acetyl transferase. It is destroyed at the onset of anaphase due to Scc1 cleavage by separase. In yeast, SMC3 acetylation is reversed at anaphase by the Hos1 deacetylase as a consequence of Scc1 cleavage. SMC3 molecules that remain acetylated after mitosis due to Hos1 inactivation cannot generate cohesion during the subsequent S phase, implying that cohesion establishment depends on de novo acetylation during DNA replication. By inducing SMC3 deacetylation in postreplicative cells due to Hos1 overexpression, we provide evidence that SMC3 acetylation contributes to the maintenance of sister chromatid cohesion. A cycle of SMC3 NBD acetylation is therefore an essential aspect of the chromosome cycle in eukaryotic cells.
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building sister chromatid cohesion SMC3 acetylation counteracts an antiestablishment activity
Molecular Cell, 2009Co-Authors: Benjamin D Rowland, Pelin Uluocak, Frederic Beckouet, Maurici B Roig, Alexander Kurze, A K Mishra, Tatsuya Nishino, Philippa Underwood, Jean Metson, Richard ImreAbstract:Summary Cohesin's Smc1, SMC3, and Scc1 subunits form a tripartite ring that entraps sister DNAs. Scc3, Pds5, and Rad61 (Wapl) are regulatory subunits that control this process. We describe here SMC3 , scc3 , pds5 , and rad61 mutations that permit yeast cell proliferation and entrapment of sister DNAs by cohesin rings in the absence of Eco1, an acetyl transferase normally essential for establishing sister chromatid cohesion. The SMC3 mutations cluster around and include a highly conserved lysine (K113) close to SMC3's ATP-binding pocket, which, together with K112, is acetylated by Eco1. Lethality caused by mutating both residues to arginine is suppressed by the scc3 , pds5 , and rad61 mutants. Scc3, Pds5, and Rad61 form a complex and inhibit entrapment of sister DNAs by a process involving the "K112/K113" surface on SMC3's ATPase. According to this model, Eco1 promotes sister DNA entrapment partly by relieving an antiestablishment activity associated with Scc3, Pds5, and Rad61.
Matthew A Deardorff - One of the best experts on this subject based on the ideXlab platform.
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de novo heterozygous mutations in SMC3 cause a range of cornelia de lange syndrome overlapping phenotypes
Human Mutation, 2015Co-Authors: Maria Concepcion Gilrodriguez, Morad Ansari, Carolina Baqueromontoya, Lilian Bomme Ousager, Maria Hernandezmarcos, Ilaria Parenti, Beatriz Puisac, Matthew A Deardorff, Maria Esperanza TeresarodrigoAbstract:Cornelia de Lange syndrome (CdLS) is characterized by facial dysmorphism, growth failure, intellectual disability, limb malformations, and multiple organ involvement. Mutations in five genes, encoding subunits of the cohesin complex (SMC1A, SMC3, RAD21) and its regulators (NIPBL, HDAC8), account for at least 70% of patients with CdLS or CdLS-like phenotypes. To date, only the clinical features from a single CdLS patient with SMC3 mutation has been published. Here, we report the efforts of an international research and clinical collaboration to provide clinical comparison of 16 patients with CdLS-like features caused by mutations in SMC3. Modeling of the mutation effects on protein structure suggests a dominant-negative effect on the multimeric cohesin complex. When compared with typical CdLS, many SMC3-associated phenotypes are also characterized by postnatal microcephaly but with a less distinctive craniofacial appearance, a milder prenatal growth retardation that worsens in childhood, few congenital heart defects, and an absence of limb deficiencies. While most mutations are unique, two unrelated affected individuals shared the same mutation but presented with different phenotypes. This work confirms that de novo SMC3 mutations account for approximate to 1%-2% of CdLS-like phenotypes.
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hdac8 mutations in cornelia de lange syndrome affect the cohesin acetylation cycle
Nature, 2012Co-Authors: Erwan Watrin, Matthew A Deardorff, Masashige Bando, Ryuichiro Nakato, Takehiko Itoh, Masashi Minamino, Katsuya Saitoh, Makiko Komata, Yuki KatouAbstract:The deacetylase enzyme HDAC8 is identified as a crucial regulator of cohesin in humans, and loss-of-function mutations in the HDAC8 gene are found in patients with Cornelia de Lange syndrome. The cohesin complex is important for sister-chromatid cohesion and chromosome segregation, as well as for other chromosomal processes such as gene expression and DNA repair. Cornelia de Lange syndrome (CdLS) is a human developmental disorder associated with significant cognitive deficits and structural birth defects. It is caused by mutations in genes that encode subunits of the cohesin complex or the cohesin regulator NIPL. Here, a deacetylase enzyme, HDAC8, is shown to be a critical regulator of cohesin in human cells, and loss-of-function HDAC8 mutations are found in six patients with CdLS from different families. Cornelia de Lange syndrome (CdLS) is a dominantly inherited congenital malformation disorder, caused by mutations in the cohesin-loading protein NIPBL1,2 for nearly 60% of individuals with classical CdLS3,4,5, and by mutations in the core cohesin components SMC1A (∼5%) and SMC3 (<1%) for a smaller fraction of probands6,7. In humans, the multisubunit complex cohesin is made up of SMC1, SMC3, RAD21 and a STAG protein. These form a ring structure that is proposed to encircle sister chromatids to mediate sister chromatid cohesion8 and also has key roles in gene regulation9. SMC3 is acetylated during S-phase to establish cohesiveness of chromatin-loaded cohesin10,11,12,13, and in yeast, the class I histone deacetylase Hos1 deacetylates SMC3 during anaphase14,15,16. Here we identify HDAC8 as the vertebrate SMC3 deacetylase, as well as loss-of-function HDAC8 mutations in six CdLS probands. Loss of HDAC8 activity results in increased SMC3 acetylation and inefficient dissolution of the ‘used’ cohesin complex released from chromatin in both prophase and anaphase. SMC3 with retained acetylation is loaded onto chromatin, and chromatin immunoprecipitation sequencing analysis demonstrates decreased occupancy of cohesin localization sites that results in a consistent pattern of altered transcription seen in CdLS cell lines with either NIPBL or HDAC8 mutations.
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hdac8 mutations in cornelia de lange syndrome affect the cohesin acetylation cycle
Nature, 2012Co-Authors: Matthew A Deardorff, Ryuichiro Nakato, Takehiko Itoh, Masashi Minamino, Katsuya Saitoh, Makiko Komata, Masashige Ando, Erwa Watri, Yuki KatouAbstract:Cornelia de Lange syndrome (CdLS) is a dominantly inherited congenital malformation disorder, caused by mutations in the cohesin-loading protein NIPBL for nearly 60% of individuals with classical CdLS, and by mutations in the core cohesin components SMC1A (~5%) and SMC3 (<1%) for a smaller fraction of probands. In humans, the multisubunit complex cohesin is made up of SMC1, SMC3, RAD21 and a STAG protein. These form a ring structure that is proposed to encircle sister chromatids to mediate sister chromatid cohesion and also has key roles in gene regulation. SMC3 is acetylated during S-phase to establish cohesiveness of chromatin-loaded cohesin, and in yeast, the class I histone deacetylase Hos1 deacetylates SMC3 during anaphase. Here we identify HDAC8 as the vertebrate SMC3 deacetylase, as well as loss-of-function HDAC8 mutations in six CdLS probands. Loss of HDAC8 activity results in increased SMC3 acetylation and inefficient dissolution of the ‘used’ cohesin complex released from chromatin in both prophase and anaphase. SMC3 with retained acetylation is loaded onto chromatin, and chromatin immunoprecipitation sequencing analysis demonstrates decreased occupancy of cohesin localization sites that results in a consistent pattern of altered transcription seen in CdLS cell lines with either NIPBL or HDAC8 mutations.
Maurici B Roig - One of the best experts on this subject based on the ideXlab platform.
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releasing activity disengages cohesin s SMC3 scc1 interface in a process blocked by acetylation
Molecular Cell, 2016Co-Authors: Thomas G Gligoris, Johanna C Scheinost, Naomi J Petela, Koklung Chan, Frederic Beckouet, Maurici B Roig, Madhusudhan Srinivasan, Paul Batty, Alexandra C SmithAbstract:Sister chromatid cohesion conferred by entrapment of sister DNAs within a tripartite ring formed between cohesin’s Scc1, Smc1, and SMC3 subunits is created during S and destroyed at anaphase through Scc1 cleavage by separase. Cohesin’s association with chromosomes is controlled by opposing activities: loading by Scc2/4 complex and release by a separase-independent releasing activity as well as by cleavage. Coentrapment of sister DNAs at replication is accompanied by acetylation of SMC3 by Eco1, which blocks releasing activity and ensures that sisters remain 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 show that mutations capable of bypassing Eco1 in Smc1, SMC3, Scc1, Wapl, Pds5, and Scc3 subunits reduce dissociation of N-terminal cleavage fragments of Scc1 (NScc1) from SMC3. This process involves interaction between Smc ATPase heads and is inhibited by SMC3 acetylation.
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cohesin s dna exit gate is distinct from its entrance gate and is regulated by acetylation
Cell, 2012Co-Authors: Koklung Chan, Frederic Beckouet, Maurici B Roig, Jean Metson, Kim NasmythAbstract:Sister chromatid cohesion is mediated by entrapment of sister DNAs by a tripartite ring composed of cohesin’s Smc1, SMC3, and α-kleisin subunits. Cohesion requires acetylation of SMC3 by Eco1, whose role is to counteract an inhibitory (antiestablishment) activity associated with cohesin’s Wapl subunit. We show that mutations abrogating antiestablishment activity also reduce turnover of cohesin on pericentric chromatin. Our results reveal a “releasing” activity inherent to cohesin complexes transiently associated with Wapl that catalyzes their dissociation from chromosomes. Fusion of SMC3’s nucleotide binding domain to α-kleisin’s N-terminal domain also reduces cohesin turnover within pericentric chromatin and permits establishment of Wapl-resistant cohesion in the absence of Eco1. We suggest that releasing activity opens the SMC3/α-kleisin interface, creating a DNA exit gate distinct from its proposed entry gate at the Smc1/3 interface. According to this notion, the function of SMC3 acetylation is to block its dissociation from α-kleisin. The functional implications of regulated ring opening are discussed.
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atp hydrolysis is required for relocating cohesin from sites occupied by its scc2 4 loading complex
Current Biology, 2011Co-Authors: Takehiko Itoh, Katsuhiko Shirahige, Koklung Chan, Maurici B Roig, A K Mishra, Yuki Katoh, William Upcher, Camilla Godlee, Kim NasmythAbstract:Summary Background The Cohesin complex that holds sister chromatins together until anaphase is comprised of three core subunits: Smc1 and SMC3, two long-rod-shaped proteins with an ABC-like ATPase head (nucleotide-binding domain [NBD]) and a dimerization domain linked by a 50 nm long intramolecular antiparallel coiled-coil, and Scc1, an α-kleisin subunit interconnecting the NBD domains of Smc1 and SMC3. Cohesin's stable association with chromosomes is thought to involve entrapment of chromatin fibers by its tripartite Smc1-SMC3-Scc1 ring via a poorly understood mechanism dependent on a separate Scc2/4 loading complex. A key issue concerns where entrapment initially takes place: at sites where cohesin is found stably associated or at distinct "loading" sites from which it translocates. Results In this study, we find transition state mutant versions (Smc1E1158Q and SmcE1155Q) defective in disengagement of their nucleotide binding domains (NBDs), unlike functional cohesin, colocalize with Scc2/4 at core centromeres, sites that catalyze wild-type cohesin's recruitment to sequences 20 kb or more away. In addition to Scc2/4, the unstable association of transition state complexes with core centromeres requires Scc1's association with Smc1 and SMC3 NBDs, ATP-driven NBD engagement, cohesin's Scc3 subunit, and its hinge domain. Conclusion We propose that cohesin's association with chromosomes is driven by two key events. NBD engagement driven by ATP binding produces an unstable association with specific loading sites like core centromeres, whereas subsequent ATP hydrolysis triggers DNA entrapment, which permits translocation along chromatin fibers.
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an SMC3 acetylation cycle is essential for establishment of sister chromatid cohesion
Molecular Cell, 2010Co-Authors: Frederic Beckouet, Makiko Komata, Katsuhiko Shirahige, Pelin Uluocak, Bin Hu, Maurici B Roig, Takashi Sutani, Vittorio L Katis, Kim NasmythAbstract:Sister chromatid cohesion is thought to involve entrapment of sister DNAs by a tripartite ring composed of the cohesin subunits Smc1, SMC3, and Scc1. Establishment of cohesion during S phase depends on acetylation of SMC3's nucleotide-binding domain (NBD) by the Eco1 acetyl transferase. It is destroyed at the onset of anaphase due to Scc1 cleavage by separase. In yeast, SMC3 acetylation is reversed at anaphase by the Hos1 deacetylase as a consequence of Scc1 cleavage. SMC3 molecules that remain acetylated after mitosis due to Hos1 inactivation cannot generate cohesion during the subsequent S phase, implying that cohesion establishment depends on de novo acetylation during DNA replication. By inducing SMC3 deacetylation in postreplicative cells due to Hos1 overexpression, we provide evidence that SMC3 acetylation contributes to the maintenance of sister chromatid cohesion. A cycle of SMC3 NBD acetylation is therefore an essential aspect of the chromosome cycle in eukaryotic cells.
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building sister chromatid cohesion SMC3 acetylation counteracts an antiestablishment activity
Molecular Cell, 2009Co-Authors: Benjamin D Rowland, Pelin Uluocak, Frederic Beckouet, Maurici B Roig, Alexander Kurze, A K Mishra, Tatsuya Nishino, Philippa Underwood, Jean Metson, Richard ImreAbstract:Summary Cohesin's Smc1, SMC3, and Scc1 subunits form a tripartite ring that entraps sister DNAs. Scc3, Pds5, and Rad61 (Wapl) are regulatory subunits that control this process. We describe here SMC3 , scc3 , pds5 , and rad61 mutations that permit yeast cell proliferation and entrapment of sister DNAs by cohesin rings in the absence of Eco1, an acetyl transferase normally essential for establishing sister chromatid cohesion. The SMC3 mutations cluster around and include a highly conserved lysine (K113) close to SMC3's ATP-binding pocket, which, together with K112, is acetylated by Eco1. Lethality caused by mutating both residues to arginine is suppressed by the scc3 , pds5 , and rad61 mutants. Scc3, Pds5, and Rad61 form a complex and inhibit entrapment of sister DNAs by a process involving the "K112/K113" surface on SMC3's ATPase. According to this model, Eco1 promotes sister DNA entrapment partly by relieving an antiestablishment activity associated with Scc3, Pds5, and Rad61.
Alexander Kurze - One of the best experts on this subject based on the ideXlab platform.
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disengaging the SMC3 kleisin interface releases cohesin from drosophila chromosomes during interphase and mitosis
The EMBO Journal, 2013Co-Authors: Christian S Eichinger, Alexander Kurze, Raquel A Oliveira, Kim NasmythAbstract:Cohesin's Smc1, SMC3, and kleisin subunits create a tripartite ring within which sister DNAs are entrapped. Evidence suggests that DNA enters through a gate created by transient dissociation of the Smc1/3 interface. Release at the onset of anaphase is triggered by proteolytic cleavage of kleisin. Less well understood is the mechanism of release at other stages of the cell cycle, in particular during prophase when most cohesin dissociates from chromosome arms in a process dependent on the regulatory subunit Wapl. We show here that Wapl-dependent release from salivary gland polytene chromosomes during interphase and from neuroblast chromosome arms during prophase is blocked by translational fusion of SMC3's C-terminus to kleisin's N-terminus. Our findings imply that proteolysis-independent release of cohesin from chromatin is mediated by Wapl-dependent escape of DNAs through a gate created by transient dissociation of the SMC3/kleisin interface. Thus, cohesin's DNA entry and exit gates are distinct.
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a positively charged channel within the smc1 SMC3 hinge required for sister chromatid cohesion
The EMBO Journal, 2011Co-Authors: Alexander Kurze, Takehiko Itoh, Katsuhiko Shirahige, Christian H. Haering, Katharine A Michie, Sarah E Dixon, A K Mishra, Syma Khalid, Lana Strmecki, Jan LoweAbstract:Cohesin's structural maintenance of chromosome 1 (Smc1) and SMC3 are rod-shaped proteins with 50-nm long intra-molecular coiled-coil arms with a heterodimerization domain at one end and an ABC-like nucleotide-binding domain (NBD) at the other. Heterodimerization creates V-shaped molecules with a hinge at their centre. Inter-connection of NBDs by Scc1 creates a tripartite ring within which, it is proposed, sister DNAs are entrapped. To investigate whether cohesin's hinge functions as a possible DNA entry gate, we solved the crystal structure of the hinge from Mus musculus, which like its bacterial counterpart is characterized by a pseudo symmetric heterodimeric torus containing a small channel that is positively charged. Mutations in yeast Smc1 and SMC3 that together neutralize the channel's charge have little effect on dimerization or association with chromosomes, but are nevertheless lethal. Our finding that neutralization reduces acetylation of SMC3, which normally occurs during replication and is essential for cohesion, suggests that the positively charged channel is involved in a major conformational change during S phase.
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building sister chromatid cohesion SMC3 acetylation counteracts an antiestablishment activity
Molecular Cell, 2009Co-Authors: Benjamin D Rowland, Pelin Uluocak, Frederic Beckouet, Maurici B Roig, Alexander Kurze, A K Mishra, Tatsuya Nishino, Philippa Underwood, Jean Metson, Richard ImreAbstract:Summary Cohesin's Smc1, SMC3, and Scc1 subunits form a tripartite ring that entraps sister DNAs. Scc3, Pds5, and Rad61 (Wapl) are regulatory subunits that control this process. We describe here SMC3 , scc3 , pds5 , and rad61 mutations that permit yeast cell proliferation and entrapment of sister DNAs by cohesin rings in the absence of Eco1, an acetyl transferase normally essential for establishing sister chromatid cohesion. The SMC3 mutations cluster around and include a highly conserved lysine (K113) close to SMC3's ATP-binding pocket, which, together with K112, is acetylated by Eco1. Lethality caused by mutating both residues to arginine is suppressed by the scc3 , pds5 , and rad61 mutants. Scc3, Pds5, and Rad61 form a complex and inhibit entrapment of sister DNAs by a process involving the "K112/K113" surface on SMC3's ATPase. According to this model, Eco1 promotes sister DNA entrapment partly by relieving an antiestablishment activity associated with Scc3, Pds5, and Rad61.
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building sister chromatid cohesion SMC3 acetylation counteracts an antiestablishment activity
Molecular Cell, 2009Co-Authors: Enjami D Rowland, Pelin Uluocak, Alexander Kurze, A K Mishra, Tatsuya Nishino, Philippa Underwood, Maurici Roig, Frederic Eckoue, Jea Metso, Richard ImreAbstract:Cohesin's Smc1, SMC3, and Scc1 subunits form a tripartite ring that entraps sister DNAs. Scc3, Pds5, and Rad61 (Wapl) are regulatory subunits that control this process. We describe here SMC3, scc3, pds5, and rad61 mutations that permit yeast cell proliferation and entrapment of sister DNAs by cohesin rings in the absence of Eco1, an acetyl transferase normally essential for establishing sister chromatid cohesion. The SMC3 mutations cluster around and include a highly conserved lysine (K113) close to SMC3's ATP-binding pocket, which, together with K112, is acetylated by Eco1. Lethality caused by mutating both residues to arginine is suppressed by the scc3, pds5, and rad61 mutants. Scc3, Pds5, and Rad61 form a complex and inhibit entrapment of sister DNAs by a process involving the "K112/K113" surface on SMC3's ATPase. According to this model, Eco1 promotes sister DNA entrapment partly by relieving an antiestablishment activity associated with Scc3, Pds5, and Rad61.
