The Experts below are selected from a list of 270 Experts worldwide ranked by ideXlab platform
Jan-michael Peters - One of the best experts on this subject based on the ideXlab platform.
-
Sister Chromatid sensitive hi c reveals the conformation of replicated human chromosomes
bioRxiv, 2020Co-Authors: Michael Mitter, Catherina Gasser, Zsuzsanna Takacs, Christoph C H Langer, Wen Tang, Gregor Jessberger, Charlie T Beales, Eva Neuner, Stefan L Ameres, Jan-michael PetersAbstract:Abstract The three-dimensional organization of the genome supports regulated gene expression, recombination, DNA repair, and chromosome segregation during mitosis. Chromosome conformation capture (Hi-C)1–3 has revealed a complex genomic landscape of internal chromosome structures in vertebrate cells4–11 yet how Sister Chromatids topologically interact in replicated chromosomes has remained elusive due to their identical sequences. Here, we present Sister-Chromatid-sensitive Hi-C (scsHi-C) based on nascent DNA labeling with 4-thio-thymidine. Genome-wide conformation maps of human chromosomes revealed that Sister Chromatid pairs interact most frequently at the boundaries of topologically associating domains (TADs). Continuous loading of a dynamic cohesin pool separates Sister-Chromatid pairs inside TADs and is required to focus Sister Chromatid contacts at TAD boundaries. We identified a subset of TADs that are overall highly paired, characterized by facultative heterochromatin, as well as insulated topological domains that form separately within individual Sister Chromatids. The rich pattern of Sister Chromatid topologies and our scsHi-C technology will make it possible to dissect how physical interactions between identical DNA molecules contribute to DNA repair, gene expression, chromosome segregation, and potentially other biological processes.
-
dynamics of Sister Chromatid resolution during cell cycle progression
Journal of Cell Biology, 2018Co-Authors: Rugile Stanyte, Jan-michael Peters, Johannes Nuebler, Claudia Blaukopf, Rudolf Hoefler, Roman R Stocsits, Daniel W GerlichAbstract:Faithful genome transmission in dividing cells requires that the two copies of each chromosome’s DNA package into separate but physically linked Sister Chromatids. The linkage between Sister Chromatids is mediated by cohesin, yet where Sister Chromatids are linked and how they resolve during cell cycle progression has remained unclear. In this study, we investigated Sister Chromatid organization in live human cells using dCas9-mEGFP labeling of endogenous genomic loci. We detected substantial Sister locus separation during G2 phase irrespective of the proximity to cohesin enrichment sites. Almost all Sister loci separated within a few hours after their respective replication and then rapidly equilibrated their average distances within dynamic chromatin polymers. Our findings explain why the topology of Sister Chromatid resolution in G2 largely reflects the DNA replication program. Furthermore, these data suggest that cohesin enrichment sites are not persistent cohesive sites in human cells. Rather, cohesion might occur at variable genomic positions within the cell population.
-
dynamics of Sister Chromatid resolution during cell cycle progression
bioRxiv, 2018Co-Authors: Rugile Stanyte, Jan-michael Peters, Johannes Nuebler, Claudia Blaukopf, Rudolf Hoefler, Roman R Stocsits, Daniel W GerlichAbstract:Faithful genome transmission in dividing cells requires that the two copies of each chromosome's DNA package into separate, but physically linked, Sister Chromatids. The linkage between Sister Chromatids is mediated by cohesin, yet where Sister Chromatids are linked and how they resolve during cell cycle progression has remained unclear. Here, we investigated Sister Chromatid organization in live human cells using dCas9-mEGFP labelling of endogenous genomic loci. We detected substantial Sister locus separation during G2 phase, irrespective of the proximity to cohesin enrichment sites. Almost all Sister loci separated within a few hours after their respective replication, and then rapidly equilibrated their average distances within dynamic chromatin polymers. Our findings explain why the topology of Sister Chromatid resolution in G2 largely reflects the DNA replication program. Further, these data suggest that cohesin enrichment sites are not persistent cohesive sites in human cells. Rather, cohesion might occur at variable genomic positions within the cell population.
-
Sister Chromatid Cohesion
Cold Spring Harbor Perspectives in Biology, 2012Co-Authors: Jan-michael Peters, Tomoko NishiyamaAbstract:During S phase, not only does DNA have to be replicated, but also newly synthesized DNA molecules have to be connected with each other. This Sister Chromatid cohesion is essential for the biorientation of chromosomes on the mitotic or meiotic spindle, and is thus an essential prerequisite for chromosome segregation. Cohesion is mediated by cohesin complexes that are thought to embrace Sister Chromatids as large rings. Cohesin binds to DNA dynamically before DNA replication and is converted into a stably DNA-bound form during replication. This conversion requires acetylation of cohesin, which in vertebrates leads to recruitment of sororin. Sororin antagonizes Wapl, a protein that is able to release cohesin from DNA, presumably by opening the cohesin ring. Inhibition of Wapl by sororin therefore “locks” cohesin rings on DNA and allows them to maintain cohesion for long periods of time in mammalian oocytes, possibly for months or even years.
-
regulation of Sister Chromatid cohesion between chromosome arms
Current Biology, 2004Co-Authors: Jan Ellenberg, Toru Hirota, Daniel W Gerlich, Juan F Gimenezabian, Izabela Sumara, Silke Hauf, Consuelo De La Torre, Jan-michael PetersAbstract:Sister Chromatid separation in anaphase depends on the removal of cohesin complexes from chromosomes [1]. In vertebrates, the bulk of cohesin is already removed from chromosome arms during prophase and prometaphase [2, 3], whereas cohesin remains at centromeres until metaphase, when cohesin is cleaved by the protease separase [3, 4]. In unperturbed mitoses, arm cohesion nevertheless persists throughout metaphase and is principally sufficient to maintain Sister Chromatid cohesion [5]. How arm cohesion is maintained until metaphase is unknown. Here we show that small amounts of cohesin can be detected in the interChromatid region of metaphase chromosome arms. If prometaphase is prolonged by treatment of cells with microtubule poisons, these cohesin complexes dissociate from chromosome arms, and arm cohesion is dissolved. If cohesin dissociation in prometaphase-arrested cells is prevented by depletion of Plk1 or inhibition of Aurora B, arm cohesion is maintained. These observations imply that, in unperturbed mitoses, small amounts of cohesin maintain arm cohesion until metaphase. When cells lacking Plk1 and Aurora B activity enter anaphase, Chromatids lose cohesin. This loss is prevented by proteasome inhibitors, implying that it depends on separase activation. Separase may therefore be able to cleave cohesin at centromeres and on chromosome arms.
Toru Hirota - One of the best experts on this subject based on the ideXlab platform.
-
Sister Chromatid resolution is an intrinsic part of chromosome organization in prophase
Nature Cell Biology, 2016Co-Authors: Kota Nagasaka, M. Julius Hossain, M. Julia Roberti, Jan Ellenberg, Toru HirotaAbstract:The formation of mitotic chromosomes requires both compaction of chromatin and the resolution of replicated Sister Chromatids. Compaction occurs during mitotic prophase and prometaphase, and in prophase relies on the activity of condensin II complexes^ 1 , 2 . Exactly when and how Sister Chromatid resolution occurs has been largely unknown, as has its molecular requirements. Here, we established a method to visualize Sister resolution by sequential replication labelling with two distinct nucleotide derivatives. Quantitative three-dimensional imaging then allowed us to measure the resolution of Sister Chromatids throughout mitosis by calculating their non-overlapping volume within the whole chromosome. Unexpectedly, we found that Sister Chromatid resolution starts already at the beginning of prophase, proceeds concomitantly with chromatin compaction and is largely completed by the end of prophase. Sister Chromatid resolution was abolished by inhibition of topoisomerase IIα and by depleting or preventing mitotic activation of condensin II, whereas blocking cohesin dissociation from chromosomes had little effect. Mitotic Sister Chromatid resolution is thus an intrinsic part of mitotic chromosome formation in prophase that relies largely on DNA decatenation and shares the molecular requirement for condensin II with prophase compaction. The imaging of individually labelled Sister Chromatids allows Nagasaka et al. to conclude that mitotic Sister chromatin resolution begins in prophase and depends on the activity of topoisomerase II and condensin II, but not on cohesin dissociation.
-
regulation of Sister Chromatid cohesion between chromosome arms
Current Biology, 2004Co-Authors: Jan Ellenberg, Toru Hirota, Daniel W Gerlich, Juan F Gimenezabian, Izabela Sumara, Silke Hauf, Consuelo De La Torre, Jan-michael PetersAbstract:Sister Chromatid separation in anaphase depends on the removal of cohesin complexes from chromosomes [1]. In vertebrates, the bulk of cohesin is already removed from chromosome arms during prophase and prometaphase [2, 3], whereas cohesin remains at centromeres until metaphase, when cohesin is cleaved by the protease separase [3, 4]. In unperturbed mitoses, arm cohesion nevertheless persists throughout metaphase and is principally sufficient to maintain Sister Chromatid cohesion [5]. How arm cohesion is maintained until metaphase is unknown. Here we show that small amounts of cohesin can be detected in the interChromatid region of metaphase chromosome arms. If prometaphase is prolonged by treatment of cells with microtubule poisons, these cohesin complexes dissociate from chromosome arms, and arm cohesion is dissolved. If cohesin dissociation in prometaphase-arrested cells is prevented by depletion of Plk1 or inhibition of Aurora B, arm cohesion is maintained. These observations imply that, in unperturbed mitoses, small amounts of cohesin maintain arm cohesion until metaphase. When cells lacking Plk1 and Aurora B activity enter anaphase, Chromatids lose cohesin. This loss is prevented by proteasome inhibitors, implying that it depends on separase activation. Separase may therefore be able to cleave cohesin at centromeres and on chromosome arms.
Daniel W Gerlich - One of the best experts on this subject based on the ideXlab platform.
-
dynamics of Sister Chromatid resolution during cell cycle progression
Journal of Cell Biology, 2018Co-Authors: Rugile Stanyte, Jan-michael Peters, Johannes Nuebler, Claudia Blaukopf, Rudolf Hoefler, Roman R Stocsits, Daniel W GerlichAbstract:Faithful genome transmission in dividing cells requires that the two copies of each chromosome’s DNA package into separate but physically linked Sister Chromatids. The linkage between Sister Chromatids is mediated by cohesin, yet where Sister Chromatids are linked and how they resolve during cell cycle progression has remained unclear. In this study, we investigated Sister Chromatid organization in live human cells using dCas9-mEGFP labeling of endogenous genomic loci. We detected substantial Sister locus separation during G2 phase irrespective of the proximity to cohesin enrichment sites. Almost all Sister loci separated within a few hours after their respective replication and then rapidly equilibrated their average distances within dynamic chromatin polymers. Our findings explain why the topology of Sister Chromatid resolution in G2 largely reflects the DNA replication program. Furthermore, these data suggest that cohesin enrichment sites are not persistent cohesive sites in human cells. Rather, cohesion might occur at variable genomic positions within the cell population.
-
dynamics of Sister Chromatid resolution during cell cycle progression
bioRxiv, 2018Co-Authors: Rugile Stanyte, Jan-michael Peters, Johannes Nuebler, Claudia Blaukopf, Rudolf Hoefler, Roman R Stocsits, Daniel W GerlichAbstract:Faithful genome transmission in dividing cells requires that the two copies of each chromosome's DNA package into separate, but physically linked, Sister Chromatids. The linkage between Sister Chromatids is mediated by cohesin, yet where Sister Chromatids are linked and how they resolve during cell cycle progression has remained unclear. Here, we investigated Sister Chromatid organization in live human cells using dCas9-mEGFP labelling of endogenous genomic loci. We detected substantial Sister locus separation during G2 phase, irrespective of the proximity to cohesin enrichment sites. Almost all Sister loci separated within a few hours after their respective replication, and then rapidly equilibrated their average distances within dynamic chromatin polymers. Our findings explain why the topology of Sister Chromatid resolution in G2 largely reflects the DNA replication program. Further, these data suggest that cohesin enrichment sites are not persistent cohesive sites in human cells. Rather, cohesion might occur at variable genomic positions within the cell population.
-
regulation of Sister Chromatid cohesion between chromosome arms
Current Biology, 2004Co-Authors: Jan Ellenberg, Toru Hirota, Daniel W Gerlich, Juan F Gimenezabian, Izabela Sumara, Silke Hauf, Consuelo De La Torre, Jan-michael PetersAbstract:Sister Chromatid separation in anaphase depends on the removal of cohesin complexes from chromosomes [1]. In vertebrates, the bulk of cohesin is already removed from chromosome arms during prophase and prometaphase [2, 3], whereas cohesin remains at centromeres until metaphase, when cohesin is cleaved by the protease separase [3, 4]. In unperturbed mitoses, arm cohesion nevertheless persists throughout metaphase and is principally sufficient to maintain Sister Chromatid cohesion [5]. How arm cohesion is maintained until metaphase is unknown. Here we show that small amounts of cohesin can be detected in the interChromatid region of metaphase chromosome arms. If prometaphase is prolonged by treatment of cells with microtubule poisons, these cohesin complexes dissociate from chromosome arms, and arm cohesion is dissolved. If cohesin dissociation in prometaphase-arrested cells is prevented by depletion of Plk1 or inhibition of Aurora B, arm cohesion is maintained. These observations imply that, in unperturbed mitoses, small amounts of cohesin maintain arm cohesion until metaphase. When cells lacking Plk1 and Aurora B activity enter anaphase, Chromatids lose cohesin. This loss is prevented by proteasome inhibitors, implying that it depends on separase activation. Separase may therefore be able to cleave cohesin at centromeres and on chromosome arms.
Philip Hieter - One of the best experts on this subject based on the ideXlab platform.
-
identification of protein complexes required for efficient Sister Chromatid cohesion
Molecular Biology of the Cell, 2004Co-Authors: Melanie L Mayer, Hong Xu, Charles Boone, Grant W. Brown, Michael Chang, Victoria Aneliunas, Teresa Kwok, Rick Newitt, Ruedi Aebersold, Philip HieterAbstract:Ctf8p is a component of Ctf18-RFC, an alternative replication factor C-like complex required for efficient Sister Chromatid cohesion in Saccharomyces cerevisiae. We performed synthetic genetic array (SGA) analysis with a ctf8 deletion strain as a primary screen to identify other nonessential genes required for efficient Sister Chromatid cohesion. We then assessed proficiency of cohesion at three chromosomal loci in strains containing deletions of the genes identified in the ctf8 SGA screen. Deletion of seven genes (CHL1, CSM3, BIM1, KAR3, TOF1, CTF4, and VIK1) resulted in defective Sister Chromatid cohesion. Mass spectrometric analysis of immunoprecipitated complexes identified a physical association between Kar3p and Vik1p and an interaction between Csm3p and Tof1p that we confirmed by coimmunoprecipitation from cell extracts. These data indicate that synthetic genetic array analysis coupled with specific secondary screens can effectively identify protein complexes functionally related to a reference gene. Furthermore, we find that genes involved in mitotic spindle integrity and positioning have a previously unrecognized role in Sister Chromatid cohesion.
-
identification of rfc ctf18p ctf8p dcc1p an alternative rfc complex required for Sister Chromatid cohesion in s cerevisiae
Molecular Cell, 2001Co-Authors: Melanie L Mayer, Steven P Gygi, Ruedi Aebersold, Philip HieterAbstract:Abstract We have identified and characterized an alternative RFC complex RFC(Ctf18p, Ctf8p, Dcc1p) that is required for Sister Chromatid cohesion and faithful chromosome transmission. Ctf18p, Ctf8p, and Dcc1p interact physically in a complex with Rfc2p, Rfc3p, Rfc4p, and Rfc5p but not with Rfc1p or Rad24p. Deletion of CTF18 , CTF8 , or DCC1 singly or in combination ( ctf18Δctf8Δdcc1Δ ) leads to sensitivity to microtubule depolymerizing drugs and a severe Sister Chromatid cohesion defect. Furthermore, temperature-sensitive mutations in RFC4 result in precocious Sister Chromatid separation. Our results highlight a novel function of the RFC proteins and support a model in which Sister Chromatid cohesion is established at the replication fork via a polymerase switching mechanism and a replication-coupled remodeling of chromatin.
Pumin Zhang - One of the best experts on this subject based on the ideXlab platform.
-
acetylation of smc3 by eco1 is required for s phase Sister Chromatid cohesion in both human and yeast
Molecular Cell, 2008Co-Authors: Jinglan Zhang, Yehua Li, Zhiwei Huang, Tao Yang, Xiaoyong Fu, Sung Yun Jung, Yi Wang, Pumin ZhangAbstract:Sister Chromatid cohesion is normally established in S phase in a process that depends on the cohesion establishment factor Eco1, a conserved acetyltransferase. However, due to the lack of known in vivo substrates, how Eco1 regulates cohesion is not understood. Here we report that yeast Eco1 and its human ortholog, ESCO1, both acetylate Smc3, a component of the cohesin complex that physically holds the Sister Chromatid together, at two conserved lysine residues. Mutating these lysine residues to a nonacetylatable form leads to increased loss of Sister Chromatid cohesion and genome instability in both yeast and human. In addition, we clarified that the acetyltransferase activity of Eco1 is essential for its function. Our study thus identified a molecular target for the acetyltransferase Eco1 and revealed that Smc3 acetylation is a conserved mechanism in regulating Sister Chromatid cohesion.
-
securin and separase phosphorylation act redundantly to maintain Sister Chromatid cohesion in mammalian cells
Molecular Biology of the Cell, 2005Co-Authors: Xingxu Huang, Rashieda Jonine Hatcher, Philippe J York, Pumin ZhangAbstract:The spindle assembly checkpoint monitors the integrity of the spindle microtubules, which attach to Sister Chromatids at kinetochores and play a vital role in preserving genome stability by preventing missegregation. A key target of the spindle assembly checkpoint is securin, the separase inhibitor. In budding yeast, loss of securin results in precocious Sister Chromatid separation when the microtubule spindle is disrupted. However, in contrast to budding yeast, mammalian securin is not required for spindle checkpoint, suggesting that there are redundant mechanisms controlling the dissolution of Sister Chromatid cohesion in the absence of securin. One candidate mechanism is the inhibitory phosphorylation of separase. We generated a nonphosphorylable point mutant (S1121A) separase allele in securin - / - mouse embryonic stem cells. Securin - / - separase + / S 1 1 2 1 A cells are viable but fail to maintain Sister Chromatid cohesion in response to the disruption of spindle microtubules, show enhanced sensitivity to nocodazole, and cannot recover from prometaphase arrest.
