151
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Moshkin YM, Doyen CM, Kan TW, Chalkley GE, Sap K, Bezstarosti K, Demmers JA, Ozgur Z, van Ijcken WFJ, Verrijzer CP. Histone chaperone NAP1 mediates sister chromatid resolution by counteracting protein phosphatase 2A. PLoS Genet 2013; 9:e1003719. [PMID: 24086141 PMCID: PMC3784504 DOI: 10.1371/journal.pgen.1003719] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Accepted: 06/26/2013] [Indexed: 12/27/2022] Open
Abstract
Chromosome duplication and transmission into daughter cells requires the precisely orchestrated binding and release of cohesin. We found that the Drosophila histone chaperone NAP1 is required for cohesin release and sister chromatid resolution during mitosis. Genome-wide surveys revealed that NAP1 and cohesin co-localize at multiple genomic loci. Proteomic and biochemical analysis established that NAP1 associates with the full cohesin complex, but it also forms a separate complex with the cohesin subunit stromalin (SA). NAP1 binding to cohesin is cell-cycle regulated and increases during G2/M phase. This causes the dissociation of protein phosphatase 2A (PP2A) from cohesin, increased phosphorylation of SA and cohesin removal in early mitosis. PP2A depletion led to a loss of centromeric cohesion. The distinct mitotic phenotypes caused by the loss of either PP2A or NAP1, were both rescued by their concomitant depletion. We conclude that the balanced antagonism between NAP1 and PP2A controls cohesin dissociation during mitosis.
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Affiliation(s)
- Yuri M. Moshkin
- Department of Biochemistry and Centre for Biomedical Genetics, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Cecile M. Doyen
- Department of Biochemistry and Centre for Biomedical Genetics, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Tsung-Wai Kan
- Department of Biochemistry and Centre for Biomedical Genetics, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Gillian E. Chalkley
- Department of Biochemistry and Centre for Biomedical Genetics, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Karen Sap
- Proteomics Center, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Karel Bezstarosti
- Proteomics Center, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Jeroen A. Demmers
- Proteomics Center, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Zeliha Ozgur
- Genomics Centre, Erasmus University Medical Center, Rotterdam, The Netherlands
| | | | - C. Peter Verrijzer
- Department of Biochemistry and Centre for Biomedical Genetics, Erasmus University Medical Center, Rotterdam, The Netherlands
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152
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Rudra S, Skibbens RV. Chl1 DNA helicase regulates Scc2 deposition specifically during DNA-replication in Saccharomyces cerevisiae. PLoS One 2013; 8:e75435. [PMID: 24086532 PMCID: PMC3784445 DOI: 10.1371/journal.pone.0075435] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Accepted: 08/13/2013] [Indexed: 11/19/2022] Open
Abstract
The conserved family of cohesin proteins that mediate sister chromatid cohesion requires Scc2, Scc4 for chromatin-association and Eco1/Ctf7 for conversion to a tethering competent state. A popular model, based on the notion that cohesins form huge ring-like structures, is that Scc2, Scc4 function is essential only during G1 such that sister chromatid cohesion results simply from DNA replisome passage through pre-loaded cohesin rings. In such a scenario, cohesin deposition during G1 is temporally uncoupled from Eco1-dependent establishment reactions that occur during S-phase. Chl1 DNA helicase (homolog of human ChlR1/DDX11 and BACH1/BRIP1/FANCJ helicases implicated in Fanconi anemia, breast and ovarian cancer and Warsaw Breakage Syndrome) plays a critical role in sister chromatid cohesion, however, the mechanism through which Chl1 promotes cohesion remains poorly understood. Here, we report that Chl1 promotes Scc2 loading unto DNA such that both Scc2 and cohesin enrichment to chromatin are defective in chl1 mutant cells. The results further show that both Chl1 expression and chromatin-recruitment are tightly regulated through the cell cycle, peaking during S-phase. Importantly, kinetic ChIP studies reveals that Chl1 is required for Scc2 chromatin-association specifically during S-phase, but not during G1. Despite normal chromatin enrichment of both Scc2 and cohesin during G1, chl1 mutant cells exhibit severe chromosome segregation and cohesion defects--revealing that G1-loaded cohesins is insufficient to promote cohesion. Based on these findings, we propose a new model wherein S-phase cohesin loading occurs during DNA replication and in concert with both cohesion establishment and chromatin assembly reactions--challenging the notion that DNA replication fork navigates through or around pre-loaded cohesin rings.
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Affiliation(s)
- Soumya Rudra
- Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania, United States of America
| | - Robert V. Skibbens
- Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania, United States of America
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153
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Kinetochore function and chromosome segregation rely on critical residues in histones H3 and H4 in budding yeast. Genetics 2013; 195:795-807. [PMID: 24037263 DOI: 10.1534/genetics.113.152082] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Accurate chromosome segregation requires that sister kinetochores biorient and attach to microtubules from opposite poles. Kinetochore biorientation relies on the underlying centromeric chromatin, which provides a platform to assemble the kinetochore and to recruit the regulatory factors that ensure the high fidelity of this process. To identify the centromeric chromatin determinants that contribute to chromosome segregation, we performed two complementary unbiased genetic screens using a library of budding yeast mutants in every residue of histone H3 and H4. In one screen, we identified mutants that lead to increased loss of a nonessential chromosome. In the second screen, we isolated mutants whose viability depends on a key regulator of biorientation, the Aurora B protein kinase. Nine mutants were common to both screens and exhibited kinetochore biorientation defects. Four of the mutants map near the unstructured nucleosome entry site, and their genetic interaction with reduced IPL1 can be suppressed by increasing the dosage of SGO1, a key regulator of biorientation. In addition, the composition of purified kinetochores was altered in six of the mutants. Together, this work identifies previously unknown histone residues involved in chromosome segregation and lays the foundation for future studies on the role of the underlying chromatin structure in chromosome segregation.
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154
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Abstract
Cohesin is a ring-shaped complex, conserved from yeast to human, that was named for its ability to mediate sister chromatid cohesion. This function is essential for chromosome segregation in both mitosis and meiosis, and also for DNA repair. In addition, more recent studies have shown that cohesin influences gene expression during development through mechanisms that likely involve DNA looping and interactions with several transcriptional regulators. Here, we provide an overview of how cohesin functions, highlighting its role both in development and in disease.
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Affiliation(s)
- Silvia Remeseiro
- Chromosome Dynamics Group, Molecular Oncology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
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155
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Kuleszewicz K, Fu X, Kudo NR. Cohesin loading factor Nipbl localizes to chromosome axes during mammalian meiotic prophase. Cell Div 2013; 8:12. [PMID: 23967866 PMCID: PMC3765518 DOI: 10.1186/1747-1028-8-12] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Accepted: 08/12/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Sister chromatid cohesion mediated by the cohesin complex is essential for accurate chromosome segregation during mitosis and meiosis. Loading of cohesin onto chromosomes is dependent on another protein complex called kollerin, containing Nipbl/Scc2 and Mau2/Scc4. Nipbl is an evolutionarily conserved large protein whose haploinsufficiency in humans causes a developmental disorder called Cornelia de Lange syndrome. Although the function of Nipbl homologues for chromosome cohesion in meiotic cells of non-vertebrate models has been elucidated, Nipbl has not been characterized so far in mammalian spermatocytes or oocytes. FINDINGS Here we describe our analyses on the expression and localization of Nipbl in nuclei of mouse spermatocytes and oocytes at different stages of meiotic prophase. In both spermatocytes and oocytes we found that Nipbl is associated with the axial/lateral element of the synaptonemal complex (AE/LE) to which cohesin also localizes. Interestingly, Nipbl in spermatocytes, but not in oocytes, dissociates from the AE/LE at mid-pachytene stage coincident with completion of DNA double-strand break repair. CONCLUSIONS Our data propose that cohesin loading activity is maintained during early stages of meiotic prophase in mammalian spermatocytes and oocytes.
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Affiliation(s)
- Katarzyna Kuleszewicz
- IRDB, Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital, London W12 0NN, UK.
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156
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Sajesh BV, Lichtensztejn Z, McManus KJ. Sister chromatid cohesion defects are associated with chromosome instability in Hodgkin lymphoma cells. BMC Cancer 2013; 13:391. [PMID: 23962039 PMCID: PMC3751861 DOI: 10.1186/1471-2407-13-391] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Accepted: 08/19/2013] [Indexed: 12/25/2022] Open
Abstract
Background Chromosome instability manifests as an abnormal chromosome complement and is a pathogenic event in cancer. Although a correlation between abnormal chromosome numbers and cancer exist, the underlying mechanisms that cause chromosome instability are poorly understood. Recent data suggests that aberrant sister chromatid cohesion causes chromosome instability and thus contributes to the development of cancer. Cohesion normally functions by tethering nascently synthesized chromatids together to prevent premature segregation and thus chromosome instability. Although the prevalence of aberrant cohesion has been reported for some solid tumors, its prevalence within liquid tumors is unknown. Consequently, the current study was undertaken to evaluate aberrant cohesion within Hodgkin lymphoma, a lymphoid malignancy that frequently exhibits chromosome instability. Methods Using established cytogenetic techniques, the prevalence of chromosome instability and aberrant cohesion was examined within mitotic spreads generated from five commonly employed Hodgkin lymphoma cell lines (L-1236, KM-H2, L-428, L-540 and HDLM-2) and a lymphocyte control. Indirect immunofluorescence and Western blot analyses were performed to evaluate the localization and expression of six critical proteins involved in the regulation of sister chromatid cohesion. Results We first confirmed that all five Hodgkin lymphoma cell lines exhibited chromosome instability relative to the lymphocyte control. We then determined that each Hodgkin lymphoma cell line exhibited cohesion defects that were subsequently classified into mild, moderate or severe categories. Surprisingly, ~50% of the mitotic spreads generated from L-540 and HDLM-2 harbored cohesion defects. To gain mechanistic insight into the underlying cause of the aberrant cohesion we examined the localization and expression of six critical proteins involved in cohesion. Although all proteins produced the expected nuclear localization pattern, striking differences in RAD21 expression was observed: RAD21 expression was lowest in L-540 and highest within HDLM-2. Conclusion We conclude that aberrant cohesion is a common feature of all five Hodgkin lymphoma cell lines evaluated. We further conclude that aberrant RAD21 expression is a strong candidate to underlie aberrant cohesion, chromosome instability and contribute to the development of the disease. Our findings support a growing body of evidence suggesting that cohesion defects and aberrant RAD21 expression are pathogenic events that contribute to tumor development.
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Affiliation(s)
- Babu V Sajesh
- Manitoba Institute of Cell Biology and the Department of Biochemistry & Medical Genetics, University of Manitoba, ON6010 - 675 McDermot Avenue, Winnipeg, Manitoba MB R3E 0V9, Canada
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157
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Yan J, Enge M, Whitington T, Dave K, Liu J, Sur I, Schmierer B, Jolma A, Kivioja T, Taipale M, Taipale J. Transcription factor binding in human cells occurs in dense clusters formed around cohesin anchor sites. Cell 2013; 154:801-13. [PMID: 23953112 DOI: 10.1016/j.cell.2013.07.034] [Citation(s) in RCA: 262] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Revised: 05/23/2013] [Accepted: 07/23/2013] [Indexed: 10/26/2022]
Abstract
During cell division, transcription factors (TFs) are removed from chromatin twice, during DNA synthesis and during condensation of chromosomes. How TFs can efficiently find their sites following these stages has been unclear. Here, we have analyzed the binding pattern of expressed TFs in human colorectal cancer cells. We find that binding of TFs is highly clustered and that the clusters are enriched in binding motifs for several major TF classes. Strikingly, almost all clusters are formed around cohesin, and loss of cohesin decreases both DNA accessibility and binding of TFs to clusters. We show that cohesin remains bound in S phase, holding the nascent sister chromatids together at the TF cluster sites. Furthermore, cohesin remains bound to the cluster sites when TFs are evicted in early M phase. These results suggest that cohesin-binding functions as a cellular memory that promotes re-establishment of TF clusters after DNA replication and chromatin condensation.
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Affiliation(s)
- Jian Yan
- Science for Life Laboratory, Department of Biosciences and Nutrition, Karolinska Institutet, Stockholm 14183, Sweden
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158
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Li Y, Huang W, Niu L, Umbach DM, Covo S, Li L. Characterization of constitutive CTCF/cohesin loci: a possible role in establishing topological domains in mammalian genomes. BMC Genomics 2013; 14:553. [PMID: 23945083 PMCID: PMC3765723 DOI: 10.1186/1471-2164-14-553] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Accepted: 07/26/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Recent studies suggested that human/mammalian genomes are divided into large, discrete domains that are units of chromosome organization. CTCF, a CCCTC binding factor, has a diverse role in genome regulation including transcriptional regulation, chromosome-boundary insulation, DNA replication, and chromatin packaging. It remains unclear whether a subset of CTCF binding sites plays a functional role in establishing/maintaining chromatin topological domains. RESULTS We systematically analysed the genomic, transcriptomic and epigenetic profiles of the CTCF binding sites in 56 human cell lines from ENCODE. We identified ~24,000 CTCF sites (referred to as constitutive sites) that were bound in more than 90% of the cell lines. Our analysis revealed: 1) constitutive CTCF loci were located in constitutive open chromatin and often co-localized with constitutive cohesin loci; 2) most constitutive CTCF loci were distant from transcription start sites and lacked CpG islands but were enriched with the full-spectrum CTCF motifs: a recently reported 33/34-mer and two other potentially novel (22/26-mer); 3) more importantly, most constitutive CTCF loci were present in CTCF-mediated chromatin interactions detected by ChIA-PET and these pair-wise interactions occurred predominantly within, but not between, topological domains identified by Hi-C. CONCLUSIONS Our results suggest that the constitutive CTCF sites may play a role in organizing/maintaining the recently identified topological domains that are common across most human cells.
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Affiliation(s)
- Yuanyuan Li
- Biostatistics Branch, National Institute of Environmental Health Sciences, Research Triangle Park, Durham, NC 27709, USA.
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159
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Singh DK, Andreuzza S, Panoli AP, Siddiqi I. AtCTF7 is required for establishment of sister chromatid cohesion and association of cohesin with chromatin during meiosis in Arabidopsis. BMC PLANT BIOLOGY 2013; 13:117. [PMID: 23941555 PMCID: PMC3751900 DOI: 10.1186/1471-2229-13-117] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 08/05/2013] [Indexed: 05/29/2023]
Abstract
BACKGROUND The establishment of sister chromatid cohesion followed by its controlled release at the metaphase to anaphase transition is necessary for faithful segregation of chromosomes in mitosis and meiosis. Cohesion is established by the action of Ctf7/Eco1 on the cohesin complex during DNA replication following loading of cohesin onto chromatin by the Scc2-Scc4 complex. Ctf7 is also required for sister chromatid cohesion during repair of DNA double strand breaks. Ctf7 contains an acetyltransferase domain and a zinc finger motif and acetylates conserved lysine residues in the Smc3 subunit of cohesin. In Arabidopsis CTF7 is encoded by a single gene and mutations in AtCTF7 cause embryo lethality indicating that the gene is essential. RESULTS To study the function of Ctf7 in plants and to determine its role in sister chromatid cohesion, we constructed a conditional allele of AtCTF7 in Arabidopsis using an inducible RNA interference (RNAi) strategy, so as to avoid the embryo lethality caused by mutations in AtCTF7. We found that induction of RNAi against AtCTF7 caused severe inhibition and defects in growth during vegetative and reproductive stages as well as sterility. AtCTF7-RNAi plants displayed chromosome fragmentation and loss of sister chromatid cohesion during meiosis. Immunostaining for the cohesion subunit AtSCC3 showed a marked reduction in association of cohesin with chromatin during meiosis in AtCTF7-RNAi plants. CONCLUSIONS We find that AtCTF7 is essential for sister chromatid cohesion during meiosis in Arabidopsis and is required for association of cohesin with chromatin in prophase of meiosis.
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Affiliation(s)
- Dipesh K Singh
- Centre for Cellular & Molecular Biology (CSIR), Uppal Road, Hyderabad 500007, India
| | - Sebastien Andreuzza
- Centre for Cellular & Molecular Biology (CSIR), Uppal Road, Hyderabad 500007, India
| | - Aneesh P Panoli
- Centre for Cellular & Molecular Biology (CSIR), Uppal Road, Hyderabad 500007, India
| | - Imran Siddiqi
- Centre for Cellular & Molecular Biology (CSIR), Uppal Road, Hyderabad 500007, India
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160
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Chan KL, Gligoris T, Upcher W, Kato Y, Shirahige K, Nasmyth K, Beckouët F. Pds5 promotes and protects cohesin acetylation. Proc Natl Acad Sci U S A 2013; 110:13020-5. [PMID: 23878248 PMCID: PMC3740900 DOI: 10.1073/pnas.1306900110] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Cohesin's Smc1 and Smc3 subunits form V-shaped heterodimers, the nucleotide binding domains (NBDs) of which bind the C- and N-terminal domains, respectively, of the α-kleisin subunit, forming a large tripartite ring within in which sister DNAs are entrapped, and thereby held together (sister chromatid cohesion). During replication, establishment of stable cohesion is dependent on Eco1-mediated acetylation of Smc3's NBD, which is thought to prevent dissociation of α-kleisin from Smc3, thereby locking shut a "DNA exit gate." How Scc3 and Pds5, regulatory subunits bound to α-kleisin, regulate cohesion establishment and maintenance is poorly understood. We show here that by binding to α-kleisin adjacent to its Smc3 nucleotide binding N-terminal domain, Pds5 not only promotes cohesin's release from chromatin but also mediates de novo acetylation of Smc3 by Eco1 during S phase and subsequently prevents de-acetylation by the deacetylase Hos1/HDAC8. By first promoting cohesin's release from chromosomes and subsequently creating and guarding the chemical modification responsible for blocking release, Pds5 enables chromosomal cohesin to switch during S phase from a state of high turnover to one capable of tenaciously holding sister chromatids together for extended periods of time, a duality that has hitherto complicated analysis of this versatile cohesin subunit.
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Affiliation(s)
- Kok-Lung Chan
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom; and
| | - Thomas Gligoris
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom; and
| | - William Upcher
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom; and
| | - Yuki Kato
- Department for Epigenetic Disease, University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Katsuhiko Shirahige
- Department for Epigenetic Disease, University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Kim Nasmyth
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom; and
| | - Frédéric Beckouët
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom; and
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161
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Ouyang Z, Zheng G, Song J, Borek DM, Otwinowski Z, Brautigam CA, Tomchick DR, Rankin S, Yu H. Structure of the human cohesin inhibitor Wapl. Proc Natl Acad Sci U S A 2013; 110:11355-60. [PMID: 23776203 PMCID: PMC3710786 DOI: 10.1073/pnas.1304594110] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Cohesin, along with positive regulators, establishes sister-chromatid cohesion by forming a ring to circle chromatin. The wings apart-like protein (Wapl) is a key negative regulator of cohesin and forms a complex with precocious dissociation of sisters protein 5 (Pds5) to promote cohesin release from chromatin. Here we report the crystal structure and functional characterization of human Wapl. Wapl contains a flexible, variable N-terminal region (Wapl-N) and a conserved C-terminal domain (Wapl-C) consisting of eight HEAT (Huntingtin, Elongation factor 3, A subunit, and target of rapamycin) repeats. Wapl-C folds into an elongated structure with two lobes. Structure-based mutagenesis maps the functional surface of Wapl-C to two distinct patches (I and II) on the N lobe and a localized patch (III) on the C lobe. Mutating critical patch I residues weaken Wapl binding to cohesin and diminish sister-chromatid resolution and cohesin release from mitotic chromosomes in human cells and Xenopus egg extracts. Surprisingly, patch III on the C lobe does not contribute to Wapl binding to cohesin or its known regulators. Although patch I mutations reduce Wapl binding to intact cohesin, they do not affect Wapl-Pds5 binding to the cohesin subcomplex of sister chromatid cohesion protein 1 (Scc1) and stromal antigen 2 (SA2) in vitro, which is instead mediated by Wapl-N. Thus, Wapl-N forms extensive interactions with Pds5 and Scc1-SA2. Wapl-C interacts with other cohesin subunits and possibly unknown effectors to trigger cohesin release from chromatin.
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Affiliation(s)
- Zhuqing Ouyang
- Howard Hughes Medical Institute, Department of Pharmacology, and
| | - Ge Zheng
- Howard Hughes Medical Institute, Department of Pharmacology, and
| | - Jianhua Song
- Program in Cell Cycle and Cancer Biology, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104
| | - Dominika M. Borek
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390; and
| | - Zbyszek Otwinowski
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390; and
| | - Chad A. Brautigam
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390; and
| | - Diana R. Tomchick
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390; and
| | - Susannah Rankin
- Program in Cell Cycle and Cancer Biology, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104
| | - Hongtao Yu
- Howard Hughes Medical Institute, Department of Pharmacology, and
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162
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Laugsch M, Seebach J, Schnittler H, Jessberger R. Imbalance of SMC1 and SMC3 cohesins causes specific and distinct effects. PLoS One 2013; 8:e65149. [PMID: 23776448 PMCID: PMC3680458 DOI: 10.1371/journal.pone.0065149] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2013] [Accepted: 04/23/2013] [Indexed: 11/24/2022] Open
Abstract
SMC1 and SMC3 form a high-affinity heterodimer, which provides an open backbone of the cohesin ring, to be closed by a kleisin protein. RNAi mediated knock-down of either one heterodimer partner, SMC1 or SMC3, is expected to cause very similar if not identical phenotypes. However, we observed highly distinct, protein-specific phenotypes. Upon knock-down of human SMC1, much of SMC3 remains stable, accumulates in the cytoplasm and does not associate with other cohesin proteins. Most of the excess nuclear SMC3 is highly mobile and not or only weakly chromosome-associated. In contrast, human SMC3 knock-down rendered SMC1 instable without cytoplasmic accumulation. As observed by differential protein extraction and in FRAP experiments the remaining SMC1 or SMC3 proteins in the respective SMC1 or SMC3 knock-down experiments constituted a cohesin pool, which is associated with chromatin with highest affinity, likely the least expendable. Expression of bovine EGFP-SMC1 or mouse EGFP-SMC3 in human cells under conditions of human SMC1 or SMC3 knock-down rescued the respective phenotypes, but in untreated cells over-expressed exogenous SMC proteins mis-localized. Paucity of either one of the SMC proteins causes RAD21 degradation. These results argue for great caution in interpreting SMC1 and SMC3 RNAi or over-expression experiments. Under challenged conditions these two proteins unexpectedly behave differently, which may have biological consequences for regulation of cohesin-associated functions and for human cohesin pathologies.
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Affiliation(s)
- Magdalena Laugsch
- Institute of Physiological Chemistry, Medical Faculty Carl Gustav Carus, Dresden University of Technology, Dresden, Germany
| | - Jochen Seebach
- Dept. of Anatomy and Vascular Biology, Westfälische Wilhelms-Universität Münster, Münster, Germany
| | - Hans Schnittler
- Dept. of Anatomy and Vascular Biology, Westfälische Wilhelms-Universität Münster, Münster, Germany
| | - Rolf Jessberger
- Institute of Physiological Chemistry, Medical Faculty Carl Gustav Carus, Dresden University of Technology, Dresden, Germany
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163
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Price JC, Pollock LM, Rudd ML, Fogoros SK, Mohamed H, Hanigan CL, Le Gallo M, Program NIHISC(NISCCS, Zhang S, Cruz P, Cherukuri PF, Hansen NF, McManus KJ, Godwin AK, Sgroi DC, Mullikin JC, Merino MJ, Hieter P, Bell DW. Sequencing of candidate chromosome instability genes in endometrial cancers reveals somatic mutations in ESCO1, CHTF18, and MRE11A. PLoS One 2013; 8:e63313. [PMID: 23755103 PMCID: PMC3670891 DOI: 10.1371/journal.pone.0063313] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Accepted: 04/01/2013] [Indexed: 01/10/2023] Open
Abstract
Most endometrial cancers can be classified histologically as endometrioid, serous, or clear cell. Non-endometrioid endometrial cancers (NEECs; serous and clear cell) are the most clinically aggressive of the three major histotypes and are characterized by aneuploidy, a feature of chromosome instability. The genetic alterations that underlie chromosome instability in endometrial cancer are poorly understood. In the present study, we used Sanger sequencing to search for nucleotide variants in the coding exons and splice junctions of 21 candidate chromosome instability genes, including 19 genes implicated in sister chromatid cohesion, from 24 primary, microsatellite-stable NEECs. Somatic mutations were verified by sequencing matched normal DNAs. We subsequently resequenced mutated genes from 41 additional NEECs as well as 42 endometrioid ECs (EECs). We uncovered nonsynonymous somatic mutations in ESCO1, CHTF18, and MRE11A in, respectively, 3.7% (4 of 107), 1.9% (2 of 107), and 1.9% (2 of 107) of endometrial tumors. Overall, 7.7% (5 of 65) of NEECs and 2.4% (1 of 42) of EECs had somatically mutated one or more of the three genes. A subset of mutations are predicted to impact protein function. The co-occurrence of somatic mutations in ESCO1 and CHTF18 was statistically significant (P = 0.0011, two-tailed Fisher's exact test). This is the first report of somatic mutations within ESCO1 and CHTF18 in endometrial tumors and of MRE11A mutations in microsatellite-stable endometrial tumors. Our findings warrant future studies to determine whether these mutations are driver events that contribute to the pathogenesis of endometrial cancer.
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Affiliation(s)
- Jessica C. Price
- Cancer Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Lana M. Pollock
- Cancer Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Meghan L. Rudd
- Cancer Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Sarah K. Fogoros
- Cancer Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Hassan Mohamed
- Cancer Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Christin L. Hanigan
- Cancer Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Matthieu Le Gallo
- Cancer Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | | | - Suiyuan Zhang
- Genome Technology Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Pedro Cruz
- Genome Technology Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Praveen F. Cherukuri
- Genome Technology Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Nancy F. Hansen
- Genome Technology Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Kirk J. McManus
- Department of Biochemistry and Medical Genetics, University of Manitoba, Manitoba Institute of Cell Biology, Winnipeg, Manitoba, Canada
| | - Andrew K. Godwin
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas City, Kansas, United States of America
- The University of Kansas Cancer Center, University of Kansas Medical Center, Kansas City, Kansas, United States of America
| | - Dennis C. Sgroi
- Molecular Pathology Unit and Center for Cancer Research, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
| | - James C. Mullikin
- Intramural Sequencing Center, National Institutes of Health, Bethesda, Maryland, United States of America
- Genome Technology Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Maria J. Merino
- Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Philip Hieter
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | - Daphne W. Bell
- Cancer Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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164
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Schaaf CA, Misulovin Z, Gause M, Koenig A, Gohara DW, Watson A, Dorsett D. Cohesin and polycomb proteins functionally interact to control transcription at silenced and active genes. PLoS Genet 2013; 9:e1003560. [PMID: 23818863 PMCID: PMC3688520 DOI: 10.1371/journal.pgen.1003560] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Accepted: 04/24/2013] [Indexed: 12/05/2022] Open
Abstract
Cohesin is crucial for proper chromosome segregation but also regulates gene transcription and organism development by poorly understood mechanisms. Using genome-wide assays in Drosophila developing wings and cultured cells, we find that cohesin functionally interacts with Polycomb group (PcG) silencing proteins at both silenced and active genes. Cohesin unexpectedly facilitates binding of Polycomb Repressive Complex 1 (PRC1) to many active genes, but their binding is mutually antagonistic at silenced genes. PRC1 depletion decreases phosphorylated RNA polymerase II and mRNA at many active genes but increases them at silenced genes. Depletion of cohesin reduces long-range interactions between Polycomb Response Elements in the invected-engrailed gene complex where it represses transcription. These studies reveal a previously unrecognized role for PRC1 in facilitating productive gene transcription and provide new insights into how cohesin and PRC1 control development.
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Affiliation(s)
- Cheri A. Schaaf
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Ziva Misulovin
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Maria Gause
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Amanda Koenig
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - David W. Gohara
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Audrey Watson
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Dale Dorsett
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
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165
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Dorsett D, Merkenschlager M. Cohesin at active genes: a unifying theme for cohesin and gene expression from model organisms to humans. Curr Opin Cell Biol 2013; 25:327-33. [PMID: 23465542 PMCID: PMC3691354 DOI: 10.1016/j.ceb.2013.02.003] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Accepted: 02/06/2013] [Indexed: 01/28/2023]
Abstract
Cohesin is an evolutionarily ancient multisubunit protein complex with a deeply conserved function: it provides cohesion between sister chromatids from the time of DNA replication in S-phase until mitosis. This cohesion facilitates repair of damage that occurs during DNA replication, and, crucially, enforces faithful segregation of chromosomes upon cell division. Cohesin also influences gene expression, and relative to sister chromatid cohesion, gene expression is exquisitely sensitive to moderate changes in cohesin activity. Early studies revealed differences in cohesin's roles in gene expression between various organisms. In all organisms examined, however, cohesin marks a subset of active genes. This review focuses on the roles of cohesin at active genes, and to what extent these roles are conserved between organisms.
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Affiliation(s)
- Dale Dorsett
- Edward A Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, Saint Louis, Missouri, 63104, USA
| | - Matthias Merkenschlager
- Lymphocyte Development Group, MRC Clinical Sciences Centre, Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0NN, UK
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166
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Dion V, Gasser SM. Chromatin movement in the maintenance of genome stability. Cell 2013; 152:1355-64. [PMID: 23498942 DOI: 10.1016/j.cell.2013.02.010] [Citation(s) in RCA: 166] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Indexed: 11/24/2022]
Abstract
Mechanistic analyses based on improved imaging techniques have begun to explore the biological implications of chromatin movement within the nucleus. Studies in both prokaryotes and eukaryotes have shed light on what regulates the mobility of DNA over long distances. Interestingly, in eukaryotes, genomic loci increase their movement in response to double-strand break induction. Break mobility, in turn, correlates with the efficiency of repair by homologous recombination. We review here the source and regulation of DNA mobility and discuss how it can both contribute to and jeopardize genome stability.
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Affiliation(s)
- Vincent Dion
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland
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167
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Gaillard H, Herrera-Moyano E, Aguilera A. Transcription-associated genome instability. Chem Rev 2013; 113:8638-61. [PMID: 23597121 DOI: 10.1021/cr400017y] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Hélène Gaillard
- Centro Andaluz de Biología Molecular y Medicina Regenerativa CABIMER, Universidad de Sevilla , Av. Américo Vespucio s/n, 41092 Seville, Spain
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168
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Hahn M, Dambacher S, Dulev S, Kuznetsova AY, Eck S, Wörz S, Sadic D, Schulte M, Mallm JP, Maiser A, Debs P, von Melchner H, Leonhardt H, Schermelleh L, Rohr K, Rippe K, Storchova Z, Schotta G. Suv4-20h2 mediates chromatin compaction and is important for cohesin recruitment to heterochromatin. Genes Dev 2013; 27:859-72. [PMID: 23599346 PMCID: PMC3650224 DOI: 10.1101/gad.210377.112] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Accepted: 03/26/2013] [Indexed: 02/05/2023]
Abstract
Cohesin plays an important role in chromatid cohesion and has additional functions in higher-order chromatin organization and in transcriptional regulation. The binding of cohesin to euchromatic regions is largely mediated by CTCF or the mediator complex. However, it is currently unknown how cohesin is recruited to pericentric heterochromatin in mammalian cells. Here we define the histone methyltransferase Suv4-20h2 as a major structural constituent of heterochromatin that mediates chromatin compaction and cohesin recruitment. Suv4-20h2 stably associates with pericentric heterochromatin through synergistic interactions with multiple heterochromatin protein 1 (HP1) molecules, resulting in compaction of heterochromatic regions. Suv4-20h mutant cells display an overall reduced chromatin compaction and an altered chromocenter organization in interphase referred to as "chromocenter scattering." We found that Suv4-20h-deficient cells display chromosome segregation defects during mitosis that coincide with reduced sister chromatid cohesion. Notably, cohesin subunits interact with Suv4-20h2 both in vitro and in vivo. This interaction is necessary for cohesin binding to heterochromatin, as Suv4-20h mutant cells display substantially reduced cohesin levels at pericentric heterochromatin. This defect is most prominent in G0-phase cells, where cohesin is virtually lost from heterochromatin, suggesting that Suv4-20h2 is involved in the initial loading or maintenance of cohesion subunits. In summary, our data provide the first compelling evidence that Suv4-20h2 plays essential roles in regulating nuclear architecture and ensuring proper chromosome segregation.
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Affiliation(s)
- Matthias Hahn
- Munich Center for Integrated Protein Science (CiPS), Ludwig Maximilians University
- Adolf-Butenandt-Institute, 80336 Munich, Germany
| | - Silvia Dambacher
- Munich Center for Integrated Protein Science (CiPS), Ludwig Maximilians University
- Adolf-Butenandt-Institute, 80336 Munich, Germany
| | - Stanimir Dulev
- Munich Center for Integrated Protein Science (CiPS), Ludwig Maximilians University
- Adolf-Butenandt-Institute, 80336 Munich, Germany
| | | | - Simon Eck
- Department of Bioinformatics and Functional Genomics, Biomedical Computer Vision Group, Institut für Pharmazie und Molekulare Biotechnologie (IPMB), BioQuant, University of Heidelberg, 69120 Heidelberg, Germany
- Deutsches Krebsforschungszentrum (DKFZ) Heidelberg, 69120 Heidelberg, Germany
| | - Stefan Wörz
- Department of Bioinformatics and Functional Genomics, Biomedical Computer Vision Group, Institut für Pharmazie und Molekulare Biotechnologie (IPMB), BioQuant, University of Heidelberg, 69120 Heidelberg, Germany
- Deutsches Krebsforschungszentrum (DKFZ) Heidelberg, 69120 Heidelberg, Germany
| | - Dennis Sadic
- Munich Center for Integrated Protein Science (CiPS), Ludwig Maximilians University
- Adolf-Butenandt-Institute, 80336 Munich, Germany
| | - Maike Schulte
- Munich Center for Integrated Protein Science (CiPS), Ludwig Maximilians University
- Adolf-Butenandt-Institute, 80336 Munich, Germany
| | - Jan-Philipp Mallm
- Deutsches Krebsforschungszentrum (DKFZ) Heidelberg, 69120 Heidelberg, Germany
- Research Group Genome Organization and Function, BioQuant, 69120 Heidelberg, Germany
| | - Andreas Maiser
- Munich Center for Integrated Protein Science (CiPS), Ludwig Maximilians University
- Department of Biology II, Biozentrum, 82152 Munich, Germany
| | - Pierre Debs
- Department of Molecular Hematology, University of Frankfurt Medical School, 60590 Frankfurt am Main, Germany
| | - Harald von Melchner
- Department of Molecular Hematology, University of Frankfurt Medical School, 60590 Frankfurt am Main, Germany
| | - Heinrich Leonhardt
- Munich Center for Integrated Protein Science (CiPS), Ludwig Maximilians University
- Department of Biology II, Biozentrum, 82152 Munich, Germany
| | - Lothar Schermelleh
- Munich Center for Integrated Protein Science (CiPS), Ludwig Maximilians University
- Department of Biology II, Biozentrum, 82152 Munich, Germany
| | - Karl Rohr
- Department of Bioinformatics and Functional Genomics, Biomedical Computer Vision Group, Institut für Pharmazie und Molekulare Biotechnologie (IPMB), BioQuant, University of Heidelberg, 69120 Heidelberg, Germany
- Deutsches Krebsforschungszentrum (DKFZ) Heidelberg, 69120 Heidelberg, Germany
| | - Karsten Rippe
- Deutsches Krebsforschungszentrum (DKFZ) Heidelberg, 69120 Heidelberg, Germany
- Research Group Genome Organization and Function, BioQuant, 69120 Heidelberg, Germany
| | - Zuzana Storchova
- Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Gunnar Schotta
- Munich Center for Integrated Protein Science (CiPS), Ludwig Maximilians University
- Adolf-Butenandt-Institute, 80336 Munich, Germany
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169
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Piazza I, Haering CH, Rutkowska A. Condensin: crafting the chromosome landscape. Chromosoma 2013; 122:175-90. [DOI: 10.1007/s00412-013-0405-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Revised: 03/03/2013] [Accepted: 03/04/2013] [Indexed: 02/06/2023]
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170
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Liu YT, Ma CH, Jayaram M. Co-segregation of yeast plasmid sisters under monopolin-directed mitosis suggests association of plasmid sisters with sister chromatids. Nucleic Acids Res 2013; 41:4144-58. [PMID: 23423352 PMCID: PMC3627588 DOI: 10.1093/nar/gkt096] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Revised: 01/23/2013] [Accepted: 01/25/2013] [Indexed: 11/13/2022] Open
Abstract
The 2-micron plasmid, a high copy extrachromosomal element in Saccharomyces cerevisiae, propagates itself with nearly the same stability as the chromosomes of its host. Plasmid stability is conferred by a partitioning system consisting of the plasmid-coded proteins Rep1 and Rep2 and a cis-acting locus STB. Circumstantial evidence suggests that the partitioning system couples plasmid segregation to chromosome segregation during mitosis. However, the coupling mechanism has not been elucidated. In order to probe into this question more incisively, we have characterized the segregation of a single-copy STB reporter plasmid by manipulating mitosis to force sister chromatids to co-segregate either without mother-daughter bias or with a finite daughter bias. We find that the STB plasmid sisters are tightly correlated to sister chromatids in the extents of co-segregation as well as the bias in co-segregation under these conditions. Furthermore, this correlation is abolished by delaying spindle organization or preventing cohesin assembly during a cell cycle. Normal segregation of the 2-micron plasmid has been shown to require spindle integrity and the cohesin complex. Our results are accommodated by a model in which spindle- and cohesin-dependent association of plasmid sisters with sister chromatids promotes their segregation by a hitchhiking mechanism.
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Affiliation(s)
| | | | - Makkuni Jayaram
- Section of Molecular Genetics & Microbiology, University of Texas at Austin, Austin, TX 78712, USA
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171
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Gabrielli B, Brown M. Histone deacetylase inhibitors disrupt the mitotic spindle assembly checkpoint by targeting histone and nonhistone proteins. Adv Cancer Res 2013; 116:1-37. [PMID: 23088867 DOI: 10.1016/b978-0-12-394387-3.00001-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Histone deacetylase inhibitors exhibit pleiotropic effects on cell functions, both in vivo and in vitro. One of the more dramatic effects of these drugs is their ability to disrupt normal mitotic division, which is a significant contributor to the anticancer properties of these drugs. The most important feature of the disrupted mitosis is that drug treatment overcomes the mitotic spindle assembly checkpoint and drives mitotic slippage, but in a manner that triggers apoptosis. The mechanism by which histone deacetylase inhibitors affect mitosis is now becoming clearer through the identification of a number of chromatin and nonchromatin protein targets that are critical to the regulation of normal mitotic progression and cell division. These proteins are directly regulated by acetylation and deacetylation, or in some cases indirectly through the acetylation of essential partner proteins. There appears to be little contribution from deacetylase inhibitor-induced transcriptional changes to the mitotic effects of these drugs. The overall mitotic phenotype of drug treatment appears to be the sum of these disrupted mechanisms.
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Affiliation(s)
- Brian Gabrielli
- The University of Queensland Diamantina Institute, Princess Alexandra Hospital, Brisbane, Queensland, Australia.
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172
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Calvente A, Viera A, Parra MT, de la Fuente R, Suja JA, Page J, Santos JL, de la Vega CG, Barbero JL, Rufas JS. Dynamics of cohesin subunits in grasshopper meiotic divisions. Chromosoma 2013; 122:77-91. [PMID: 23283389 DOI: 10.1007/s00412-012-0393-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Revised: 11/08/2012] [Accepted: 12/01/2012] [Indexed: 01/18/2023]
Abstract
The cohesin complex plays a key role for the maintenance of sister chromatid cohesion and faithful chromosome segregation in both mitosis and meiosis. This complex is formed by two structural maintenance of chromosomes protein family (SMC) subunits and two non-SMC subunits: an α-kleisin subunit SCC1/RAD21/REC8 and an SCC3-like protein. Several studies carried out in different species have revealed that the distribution of the cohesin subunits along the chromosomes during meiotic prophase I is not regular and that some subunits are distinctly incorporated at different cell stages. However, the accurate distribution of the different cohesin subunits in condensed meiotic chromosomes is still controversial. Here, we describe the dynamics of the cohesin subunits SMC1α, SMC3, RAD21 and SA1 during both meiotic divisions in grasshoppers. Although these subunits show a similar patched labelling at the interchromatid domain of metaphase I bivalents, SMCs and non-SMCs subunits do not always colocalise. Indeed, SA1 is the only cohesin subunit accumulated at the centromeric region of all metaphase I chromosomes. Additionally, non-SMC subunits do not appear at the interchromatid domain in either single X or B chromosomes. These data suggest the existence of several cohesin complexes during metaphase I. The cohesin subunits analysed are released from chromosomes at the beginning of anaphase I, with the exception of SA1 which can be detected at the centromeres until telophase II. These observations indicate that the cohesin components may be differentially loaded and released from meiotic chromosomes during the first and second meiotic divisions. The roles of these cohesin complexes for the maintenance of chromosome structure and their involvement in homologous segregation at first meiotic division are proposed and discussed.
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Affiliation(s)
- A Calvente
- Departamento de Biología, Facultad de Ciencias, Edificio de Biológicas, Universidad Autónoma de Madrid, 28049 Madrid, Spain
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173
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Murdoch B, Owen N, Stevense M, Smith H, Nagaoka S, Hassold T, McKay M, Xu H, Fu J, Revenkova E, Jessberger R, Hunt P. Altered cohesin gene dosage affects Mammalian meiotic chromosome structure and behavior. PLoS Genet 2013; 9:e1003241. [PMID: 23408896 PMCID: PMC3567145 DOI: 10.1371/journal.pgen.1003241] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Accepted: 11/28/2012] [Indexed: 01/03/2023] Open
Abstract
Based on studies in mice and humans, cohesin loss from chromosomes during the period of protracted meiotic arrest appears to play a major role in chromosome segregation errors during female meiosis. In mice, mutations in meiosis-specific cohesin genes cause meiotic disturbances and infertility. However, the more clinically relevant situation, heterozygosity for mutations in these genes, has not been evaluated. We report here evidence from the mouse that partial loss of gene function for either Smc1b or Rec8 causes perturbations in the formation of the synaptonemal complex (SC) and affects both synapsis and recombination between homologs during meiotic prophase. Importantly, these defects increase the frequency of chromosomally abnormal eggs in the adult female. These findings have important implications for humans: they suggest that women who carry mutations or variants that affect cohesin function have an elevated risk of aneuploid pregnancies and may even be at increased risk of transmitting structural chromosome abnormalities.
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Affiliation(s)
- Brenda Murdoch
- School of Molecular Biosciences, Washington State University, Pullman, Washington, United States of America
| | - Nichole Owen
- School of Molecular Biosciences, Washington State University, Pullman, Washington, United States of America
| | - Michelle Stevense
- Institute of Physiological Chemistry, Technische Universität Dresden, Dresden, Germany
| | - Helen Smith
- School of Molecular Biosciences, Washington State University, Pullman, Washington, United States of America
| | - So Nagaoka
- School of Molecular Biosciences, Washington State University, Pullman, Washington, United States of America
| | - Terry Hassold
- School of Molecular Biosciences, Washington State University, Pullman, Washington, United States of America
| | - Michael McKay
- Sydney University and the North Coast Cancer Institute, Lismore, New South Wales, Australia
| | - Huiling Xu
- Divisions of Research and Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne, Victoria, Australia
| | - Jun Fu
- Genomics, BioTec, Technische Universität Dresden, Dresden, Germany
| | - Ekaterina Revenkova
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, New York, United States of America
| | - Rolf Jessberger
- Institute of Physiological Chemistry, Technische Universität Dresden, Dresden, Germany
| | - Patricia Hunt
- School of Molecular Biosciences, Washington State University, Pullman, Washington, United States of America
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174
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Remeseiro S, Losada A. Cohesin, a chromatin engagement ring. Curr Opin Cell Biol 2013; 25:63-71. [PMID: 23219370 DOI: 10.1016/j.ceb.2012.10.013] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Accepted: 10/18/2012] [Indexed: 12/15/2022]
Abstract
Cohesin is a four subunit complex, conserved from yeast to man, with the ability to hold together two DNA segments within its ring-shaped structure. When the two segments belong to sister chromatids, cohesin is mediating cohesion, which is essential for chromosome segregation in mitosis and meiosis and for homologous DNA repair. When the two DNA segments are in the same chromatid, a loop is formed. These chromatin loops are emerging as a mechanism for controlling the communication between enhancers and promoters and thereby regulate gene expression. They also facilitate DNA replication and recombination. Given all its essential functions, it is not surprising that mutations in cohesin and its interacting factors have been associated to cancer and developmental syndromes known as cohesinopathies.
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Affiliation(s)
- Silvia Remeseiro
- Chromosome Dynamics Group, Molecular Oncology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
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175
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Disengaging the Smc3/kleisin interface releases cohesin from Drosophila chromosomes during interphase and mitosis. EMBO J 2013; 32:656-65. [PMID: 23340528 DOI: 10.1038/emboj.2012.346] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Accepted: 12/13/2012] [Indexed: 12/20/2022] Open
Abstract
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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176
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Alonso B, Beraud C, Meguellati S, Chen SW, Pellequer JL, Armengaud J, Godon C. Eukaryotic GPN-loop GTPases paralogs use a dimeric assembly reminiscent of archeal GPN. Cell Cycle 2013; 12:463-72. [PMID: 23324351 PMCID: PMC3587447 DOI: 10.4161/cc.23367] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
GTPases are molecular switches that regulate a wide-range of cellular processes. The GPN-loop GTPase (GPN) is a sub-family of P-loop NTPase that evolved from a single gene copy in archaea to triplicate paralog genes in eukaryotes, each having a non-redundant essential function in cell. In Saccharomyces cerevisiae, yGPN1 and yGPN2 are involved in sister chromatid cohesion mechanism, whereas nothing is known regarding yGPN3 function. Previous high-throughput experiments suggested that GPN paralogs interaction may occur. In this work, GPN|GPN contact was analyzed in details using TAP-Tag approach, yeast two-hybrid assay, in silico energy computation and site-directed mutagenesis of a conserved Glu residue located at the center of the interaction interface. It is demonstrated that this residue is essential for cell viability. A chromatid cohesion assay revealed that, like yGPN1 and yGPN2, yGPN3 also plays a role in sister chromatid cohesion. These results suggest that all three GPN proteins act at the molecular level in sister chromatid cohesion mechanism as a GPN|GPN complex reminiscent of the homodimeric structure of PAB0955, an archaeal member of GPN-loop GTPase.
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Affiliation(s)
- Béatrice Alonso
- CEA, iBEB, Service de Biochimie et Toxicologie Nucléaire/LBSP, Bagnols-sur-Cèze, France
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177
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McAleenan A, Clemente-Blanco A, Cordon-Preciado V, Sen N, Esteras M, Jarmuz A, Aragón L. Post-replicative repair involves separase-dependent removal of the kleisin subunit of cohesin. Nature 2013; 493:250-4. [PMID: 23178808 DOI: 10.1038/nature11630] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Accepted: 09/28/2012] [Indexed: 01/18/2023]
Abstract
DNA double-strand break repair is critical for cell viability and involves highly coordinated pathways to restore DNA integrity at the lesion. An early event during homology-dependent repair is resection of the break to generate progressively longer 3' single-strand tails that are used to identify suitable templates for repair. Sister chromatids provide near-perfect sequence homology and are therefore the preferred templates during homologous recombination. To provide a bias for the use of sisters as donors, cohesin--the complex that tethers sister chromatids together--is recruited to the break to enforce physical proximity. Here we show that DNA breaks promote dissociation of cohesin loaded during the previous S phase in budding yeast, and that damage-induced dissociation of cohesin requires separase, the protease that dissolves cohesion in anaphase. Moreover, a separase-resistant allele of the gene coding for the α-kleisin subunit of cohesin, Mcd1 (also known as Scc1), reduces double-strand break resection and compromises the efficiency of repair even when loaded during DNA damage. We conclude that post-replicative DNA repair involves cohesin dissociation by separase to promote accessibility to repair factors during the coordinated cellular response to restore DNA integrity.
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Affiliation(s)
- Alexandra McAleenan
- Cell Cycle Group, MRC Clinical Sciences Centre, Imperial College, Du Cane Road, London W12 0NN, UK
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178
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Abstract
Sister chromatid cohesion depends on cohesin, a tripartite complex that forms ring structures to hold sister chromatids together in mitosis and meiosis. Meiocytes feature a multiplicity of distinct cohesin proteins and complexes, some meiosis specific, which serve additional functions such as supporting synapsis of two pairs of sister chromatids and determining the loop-axis architecture of prophase I chromosomes. Despite considerable new insights gained in the past few years into the localization and function of some cohesin proteins, and the recent identification of yet another meiosis-specific cohesin subunit, a plethora of open questions remains, which concern not only fundamental germ cell biology but also the consequences of cohesin impairment for human reproductive health.
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Affiliation(s)
- François McNicoll
- Institute of Physiological Chemistry, Medical Faculty Carl Gustav Carus, Dresden University of Technology, Dresden, Germany
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179
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Liu H, Rankin S, Yu H. Phosphorylation-enabled binding of SGO1-PP2A to cohesin protects sororin and centromeric cohesion during mitosis. Nat Cell Biol 2013; 15:40-9. [PMID: 23242214 PMCID: PMC3531828 DOI: 10.1038/ncb2637] [Citation(s) in RCA: 140] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Accepted: 11/01/2012] [Indexed: 12/14/2022]
Abstract
Timely dissolution of sister-chromatid cohesion in mitosis ensures accurate chromosome segregation to guard against aneuploidy and tumorigenesis. The complex of shugoshin and protein phosphatase 2A (SGO1-PP2A) protects cohesin at centromeres from premature removal by mitotic kinases and WAPL in prophase. Here we address the regulation and mechanism of human SGO1 in centromeric cohesion protection, and show that cyclin-dependent kinase (CDK)-mediated, mitosis-specific phosphorylation of SGO1 activates its cohesion-protection function and enables its direct binding to cohesin. The phospho-SGO1-bound cohesin complex contains PP2A, PDS5 and hypophosphorylated sororin, but lacks WAPL. Expression of non-phosphorylatable sororin bypasses the requirement for SGO1-PP2A in centromeric cohesion. Thus, mitotic phosphorylation of SGO1 targets SGO1-PP2A to cohesin, promotes dephosphorylation of PDS5-bound sororin and protects centromeric cohesin from WAPL. PP2A-orchestrated, site-selective dephosphorylation of cohesin and its regulators underlies centromeric cohesion protection.
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Affiliation(s)
- Hong Liu
- Department of Pharmacology, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75390
| | - Susannah Rankin
- Program in Cell Cycle and Cancer Biology, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104
| | - Hongtao Yu
- Department of Pharmacology, Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75390
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180
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Redondo-Muñoz J, Rodríguez MJ, Silió V, Pérez-García V, Valpuesta JM, Carrera AC. Phosphoinositide 3-kinase beta controls replication factor C assembly and function. Nucleic Acids Res 2012; 41:855-68. [PMID: 23175608 PMCID: PMC3553946 DOI: 10.1093/nar/gks1095] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Genomic integrity is preserved by the action of protein complexes that control DNA homeostasis. These include the sliding clamps, trimeric protein rings that are arranged around DNA by clamp loaders. Replication factor C (RFC) is the clamp loader for proliferating cell nuclear antigen, which acts on DNA replication. Other processes that require mobile contact of proteins with DNA use alternative RFC complexes that exchange RFC1 for CTF18 or RAD17. Phosphoinositide 3-kinases (PI3K) are lipid kinases that generate 3-poly-phosphorylated-phosphoinositides at the plasma membrane following receptor stimulation. The two ubiquitous isoforms, PI3Kalpha and PI3Kbeta, have been extensively studied due to their involvement in cancer and nuclear PI3Kbeta has been found to regulate DNA replication and repair, processes controlled by molecular clamps. We studied here whether PI3Kbeta directly controls the process of molecular clamps loading. We show that PI3Kbeta associated with RFC1 and RFC1-like subunits. Only when in complex with PI3Kbeta, RFC1 bound to Ran GTPase and localized to the nucleus, suggesting that PI3Kbeta regulates RFC1 nuclear import. PI3Kbeta controlled not only RFC1- and RFC-RAD17 complexes, but also RFC-CTF18, in turn affecting CTF18-mediated chromatid cohesion. PI3Kbeta thus has a general function in genomic stability by controlling the localization and function of RFC complexes.
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Affiliation(s)
- Javier Redondo-Muñoz
- Department of Immunology and Oncology, Centro Nacional de Biotecnología (CNB-CSIC), Darwin 3, Campus de Cantoblanco, Madrid E-28049, Spain
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181
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Yamagishi Y, Watanabe Y. Cell biology: cohesin ring exit gate revealed. Curr Biol 2012; 22:R958-60. [PMID: 23174299 DOI: 10.1016/j.cub.2012.09.049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A multiprotein complex called cohesin mediates sister chromatid cohesion by entrapping sister DNAs into a tripartite ring. Recent studies show that Wapl opens the newly identified DNA exit gate of the cohesin ring, only when Smc3 is deacetylated, and that mutations in human Smc3 deacetylase cause a developmental disorder.
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Affiliation(s)
- Yuya Yamagishi
- Laboratory of Chomosome Dynamics, Institute of Molecular and Cellular Biosciences, University of Tokyo, 1-1-1Yayoi, Tokyo 113-0032, Japan
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182
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Gimigliano A, Mannini L, Bianchi L, Puglia M, Deardorff MA, Menga S, Krantz ID, Musio A, Bini L. Proteomic profile identifies dysregulated pathways in Cornelia de Lange syndrome cells with distinct mutations in SMC1A and SMC3 genes. J Proteome Res 2012; 11:6111-23. [PMID: 23106691 DOI: 10.1021/pr300760p] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Mutations in cohesin genes have been identified in Cornelia de Lange syndrome (CdLS), but its etiopathogenetic mechanisms are still poorly understood. To define biochemical pathways that are affected in CdLS, we analyzed the proteomic profile of CdLS cell lines carrying mutations in the core cohesin genes, SMC1A and SMC3. Dysregulated protein expression was found in CdLS probands compared to controls. The proteomics analysis was able to discriminate between probands harboring mutations in the different domains of the SMC proteins. In particular, proteins involved in the response to oxidative stress were specifically down-regulated in hinge mutated probands. In addition, the finding that CdLS cell lines show an increase in global oxidative stress argues that it could contribute to some CdLS phenotypic features such as premature physiological aging and genome instability. Finally, the c-MYC gene represents a convergent hub lying at the center of dysregulated pathways, and is down-regulated in CdLS. This study allowed us to highlight, for the first time, specific biochemical pathways that are affected in CdLS, providing plausible causal evidence for some of the phenotypic features seen in CdLS.
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Affiliation(s)
- Anna Gimigliano
- Functional Proteomics Laboratory, Department of Biotechnologies, University of Siena, Siena, Italy
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183
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Abstract
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.
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184
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Varshavsky A. Augmented generation of protein fragments during wakefulness as the molecular cause of sleep: a hypothesis. Protein Sci 2012; 21:1634-61. [PMID: 22930402 PMCID: PMC3527701 DOI: 10.1002/pro.2148] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Accepted: 08/21/2012] [Indexed: 02/05/2023]
Abstract
Despite extensive understanding of sleep regulation, the molecular-level cause and function of sleep are unknown. I suggest that they originate in individual neurons and stem from increased production of protein fragments during wakefulness. These fragments are transient parts of protein complexes in which the fragments were generated. Neuronal Ca²⁺ fluxes are higher during wakefulness than during sleep. Subunits of transmembrane channels and other proteins are cleaved by Ca²⁺-activated calpains and by other nonprocessive proteases, including caspases and secretases. In the proposed concept, termed the fragment generation (FG) hypothesis, sleep is a state during which the production of fragments is decreased (owing to lower Ca²⁺ transients) while fragment-destroying pathways are upregulated. These changes facilitate the elimination of fragments and the remodeling of protein complexes in which the fragments resided. The FG hypothesis posits that a proteolytic cleavage, which produces two fragments, can have both deleterious effects and fitness-increasing functions. This (previously not considered) dichotomy can explain both the conservation of cleavage sites in proteins and the evolutionary persistence of sleep, because sleep would counteract deleterious aspects of protein fragments. The FG hypothesis leads to new explanations of sleep phenomena, including a longer sleep after sleep deprivation. Studies in the 1970s showed that ethanol-induced sleep in mice can be strikingly prolonged by intracerebroventricular injections of either Ca²⁺ alone or Ca²⁺ and its ionophore (Erickson et al., Science 1978;199:1219-1221; Harris, Pharmacol Biochem Behav 1979;10:527-534; Erickson et al., Pharmacol Biochem Behav 1980;12:651-656). These results, which were never interpreted in connection to protein fragments or the function of sleep, may be accounted for by the FG hypothesis about molecular causation of sleep.
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Affiliation(s)
- Alexander Varshavsky
- Division of Biology, California Institute of Technology, Pasadena, California 91125, USA.
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185
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Cunningham MD, Gause M, Cheng Y, Noyes A, Dorsett D, Kennison JA, Kassis JA. Wapl antagonizes cohesin binding and promotes Polycomb-group silencing in Drosophila. Development 2012; 139:4172-9. [PMID: 23034634 DOI: 10.1242/dev.084566] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Wapl protein regulates binding of the cohesin complex to chromosomes during interphase and helps remove cohesin from chromosomes at mitosis. We isolated a dominant mutation in wapl (wapl(AG)) in a screen for mutations that counteract silencing mediated by an engrailed Polycomb-group response element. wapl(AG) hemizygotes die as pharate adults and have an extra sex combs phenotype characteristic of males with mutations in Polycomb-group (PcG) genes. The wapl gene encodes two proteins, a long form and a short form. wapl(AG) introduces a stop codon at amino acid 271 of the long form and produces a truncated protein. The expression of a transgene encoding the truncated Wapl-AG protein causes an extra-sex-comb phenotype similar to that seen in the wapl(AG) mutant. Mutations in the cohesin-associated genes Nipped-B and pds5 suppress and enhance wapl(AG) phenotypes, respectively. A Pds5-Wapl complex (releasin) removes cohesin from DNA, while Nipped-B loads cohesin. This suggests that Wapl-AG might exert its effects through changes in cohesin binding. Consistent with this model, Wapl-AG was found to increase the stability of cohesin binding to polytene chromosomes. Our data suggest that increasing cohesin stability interferes with PcG silencing at genes that are co-regulated by cohesin and PcG proteins.
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Affiliation(s)
- Melissa D Cunningham
- Program in Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
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186
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Horsfield JA, Print CG, Mönnich M. Diverse developmental disorders from the one ring: distinct molecular pathways underlie the cohesinopathies. Front Genet 2012; 3:171. [PMID: 22988450 PMCID: PMC3439829 DOI: 10.3389/fgene.2012.00171] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2012] [Accepted: 08/17/2012] [Indexed: 11/13/2022] Open
Abstract
The multi-subunit protein complex, cohesin, is responsible for sister chromatid cohesion during cell division. The interaction of cohesin with DNA is controlled by a number of additional regulatory proteins. Mutations in cohesin, or its regulators, cause a spectrum of human developmental syndromes known as the “cohesinopathies.” Cohesinopathy disorders include Cornelia de Lange Syndrome and Roberts Syndrome. The discovery of novel roles for chromatid cohesion proteins in regulating gene expression led to the idea that cohesinopathies are caused by dysregulation of multiple genes downstream of mutations in cohesion proteins. Consistent with this idea, Drosophila, mouse, and zebrafish cohesinopathy models all show altered expression of developmental genes. However, there appears to be incomplete overlap among dysregulated genes downstream of mutations in different components of the cohesion apparatus. This is surprising because mutations in all cohesion proteins would be predicted to affect cohesin’s roles in cell division and gene expression in similar ways. Here we review the differences and similarities between genetic pathways downstream of components of the cohesion apparatus, and discuss how such differences might arise, and contribute to the spectrum of cohesinopathy disorders. We propose that mutations in different elements of the cohesion apparatus have distinct developmental outcomes that can be explained by sometimes subtly different molecular effects.
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Affiliation(s)
- Julia A Horsfield
- Department of Pathology, Dunedin School of Medicine, The University of Otago Dunedin, New Zealand
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187
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Chan KL, Roig M, Hu B, Beckouët F, Metson J, Nasmyth K. Cohesin's DNA exit gate is distinct from its entrance gate and is regulated by acetylation. Cell 2012; 150:961-74. [PMID: 22901742 PMCID: PMC3485559 DOI: 10.1016/j.cell.2012.07.028] [Citation(s) in RCA: 178] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Revised: 04/27/2012] [Accepted: 07/02/2012] [Indexed: 12/15/2022]
Abstract
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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Affiliation(s)
- Kok-Lung Chan
- University of Oxford, Department of Biochemistry, South Parks Road, Oxford OX1 3QU, UK
| | - Maurici B. Roig
- University of Oxford, Department of Biochemistry, South Parks Road, Oxford OX1 3QU, UK
| | - Bin Hu
- University of Oxford, Department of Biochemistry, South Parks Road, Oxford OX1 3QU, UK
| | - Frédéric Beckouët
- University of Oxford, Department of Biochemistry, South Parks Road, Oxford OX1 3QU, UK
| | - Jean Metson
- University of Oxford, Department of Biochemistry, South Parks Road, Oxford OX1 3QU, UK
| | - Kim Nasmyth
- University of Oxford, Department of Biochemistry, South Parks Road, Oxford OX1 3QU, UK
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188
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Fasulo B, Deuring R, Murawska M, Gause M, Dorighi KM, Schaaf CA, Dorsett D, Brehm A, Tamkun JW. The Drosophila MI-2 chromatin-remodeling factor regulates higher-order chromatin structure and cohesin dynamics in vivo. PLoS Genet 2012; 8:e1002878. [PMID: 22912596 PMCID: PMC3415455 DOI: 10.1371/journal.pgen.1002878] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Accepted: 06/17/2012] [Indexed: 11/24/2022] Open
Abstract
dMi-2 is a highly conserved ATP-dependent chromatin-remodeling factor that regulates transcription and cell fates by altering the structure or positioning of nucleosomes. Here we report an unanticipated role for dMi-2 in the regulation of higher-order chromatin structure in Drosophila. Loss of dMi-2 function causes salivary gland polytene chromosomes to lose their characteristic banding pattern and appear more condensed than normal. Conversely, increased expression of dMi-2 triggers decondensation of polytene chromosomes accompanied by a significant increase in nuclear volume; this effect is relatively rapid and is dependent on the ATPase activity of dMi-2. Live analysis revealed that dMi-2 disrupts interactions between the aligned chromatids of salivary gland polytene chromosomes. dMi-2 and the cohesin complex are enriched at sites of active transcription; fluorescence-recovery after photobleaching (FRAP) assays showed that dMi-2 decreases stable association of cohesin with polytene chromosomes. These findings demonstrate that dMi-2 is an important regulator of both chromosome condensation and cohesin binding in interphase cells.
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Affiliation(s)
- Barbara Fasulo
- Department of Molecular, Cell, and Developmental Biology, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Renate Deuring
- Department of Molecular, Cell, and Developmental Biology, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Magdalena Murawska
- Institute for Molecular Biology and Tumor Research (IMT), Philipps-University of Marburg, Marburg, Germany
| | - Maria Gause
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Kristel M. Dorighi
- Department of Molecular, Cell, and Developmental Biology, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Cheri A. Schaaf
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Dale Dorsett
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, Saint Louis, Missouri, United States of America
| | - Alexander Brehm
- Institute for Molecular Biology and Tumor Research (IMT), Philipps-University of Marburg, Marburg, Germany
| | - John W. Tamkun
- Department of Molecular, Cell, and Developmental Biology, University of California Santa Cruz, Santa Cruz, California, United States of America
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189
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Mehta GD, Rizvi SMA, Ghosh SK. Cohesin: a guardian of genome integrity. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1823:1324-42. [PMID: 22677545 DOI: 10.1016/j.bbamcr.2012.05.027] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2012] [Revised: 05/16/2012] [Accepted: 05/25/2012] [Indexed: 01/05/2023]
Abstract
Ability to reproduce is one of the hallmark features of all life forms by which new organisms are produced from their progenitors. During this process each cell duplicates its genome and passes a copy of its genome to the daughter cells along with the cellular matrix. Unlike bacteria, in eukaryotes there is a definite time gap between when the genome is duplicated and when it is physically separated. Therefore, for precise halving of the duplicated genome into two, it is required that each pair of duplicated chromosomes, termed sister chromatids, should be paired together in a binary fashion from the moment they are generated. This pairing function between the duplicated genome is primarily provided by a multimeric protein complex, called cohesin. Thus, genome integrity largely depends on cohesin as it ensures faithful chromosome segregation by holding the sister chromatids glued together from S phase to anaphase. In this review, we have discussed the life cycle of cohesin during both mitotic and meiotic cell divisions including the structure and architecture of cohesin complex, relevance of cohesin associated proteins, mechanism of cohesin loading onto the chromatin, cohesion establishment and the mechanism of cohesin disassembly during anaphase to separate the sister chromatids. We have also focused on the role of posttranslational modifications in cohesin biology. For better understanding of the complexity of the cohesin regulatory network to the readers, we have presented an interactome profiling of cohesin core subunits in budding yeast during mitosis and meiosis.
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Affiliation(s)
- Gunjan D Mehta
- Department of Biosciences and Bioengineering, Wadhwani Research Centre for Biosciences and Bioengineering, Indian Institute of Technology, Bombay, India
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190
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Haering CH, Jessberger R. Cohesin in determining chromosome architecture. Exp Cell Res 2012; 318:1386-93. [PMID: 22472347 DOI: 10.1016/j.yexcr.2012.03.016] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Revised: 03/16/2012] [Accepted: 03/16/2012] [Indexed: 12/27/2022]
Abstract
Cells use ring-like structured protein complexes for various tasks in DNA dynamics. The tripartite cohesin ring is particularly suited to determine chromosome architecture, for it is large and dynamic, may acquire different forms, and is involved in several distinct nuclear processes. This review focuses on cohesin's role in structuring chromosomes during mitotic and meiotic cell divisions and during interphase.
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Affiliation(s)
- Christian H Haering
- Cell Biology & Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany.
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191
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Vagnarelli P. Mitotic chromosome condensation in vertebrates. Exp Cell Res 2012; 318:1435-41. [DOI: 10.1016/j.yexcr.2012.03.017] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Revised: 03/15/2012] [Accepted: 03/15/2012] [Indexed: 01/21/2023]
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192
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Vaur S, Feytout A, Vazquez S, Javerzat JP. Pds5 promotes cohesin acetylation and stable cohesin-chromosome interaction. EMBO Rep 2012; 13:645-52. [PMID: 22640989 PMCID: PMC3388792 DOI: 10.1038/embor.2012.72] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Revised: 04/06/2012] [Accepted: 04/26/2012] [Indexed: 12/22/2022] Open
Abstract
Pds5 and Wpl1 act as anti-establishment factors preventing sister-chromatid cohesion until counteracted in S-phase by the cohesin acetyl-transferase Eso1. However, Pds5 is also required to maintain sister-chromatid cohesion in G2. Here, we show that Pds5 is essential for cohesin acetylation by Eso1 and ensures the maintenance of cohesion by promoting a stable cohesin interaction with replicated chromosomes. The latter requires Eso1 only in the presence of Wapl, indicating that cohesin stabilization relies on Eso1 only to neutralize the anti-establishment activity. We suggest that Eso1 requires Pds5 to counteract anti-establishment. This allows both cohesion establishment and Pds5-dependent stable cohesin binding to chromosomes.
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Affiliation(s)
- Sabine Vaur
- University Bordeaux, Institut de Biochimie et Génétique Cellulaires, UMR 5095, F-33000 Bordeaux, France
- CNRS, UMR 5095, F-33000 Bordeaux, France
| | - Amélie Feytout
- University Bordeaux, Institut de Biochimie et Génétique Cellulaires, UMR 5095, F-33000 Bordeaux, France
- CNRS, UMR 5095, F-33000 Bordeaux, France
| | - Stéphanie Vazquez
- University Bordeaux, Institut de Biochimie et Génétique Cellulaires, UMR 5095, F-33000 Bordeaux, France
- CNRS, UMR 5095, F-33000 Bordeaux, France
| | - Jean-Paul Javerzat
- University Bordeaux, Institut de Biochimie et Génétique Cellulaires, UMR 5095, F-33000 Bordeaux, France
- CNRS, UMR 5095, F-33000 Bordeaux, France
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193
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Bermudez VP, Farina A, Higashi TL, Du F, Tappin I, Takahashi TS, Hurwitz J. In vitro loading of human cohesin on DNA by the human Scc2-Scc4 loader complex. Proc Natl Acad Sci U S A 2012; 109:9366-71. [PMID: 22628566 PMCID: PMC3386075 DOI: 10.1073/pnas.1206840109] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The loading of cohesin onto chromatin requires the heterodimeric complex sister chromatid cohesion (Scc)2 and Scc4 (Scc2/4), which is highly conserved in all species. Here, we describe the purification of the human (h)-Scc2/4 and show that it interacts with h-cohesin and the heterodimeric Smc1-Smc3 complex but not with the Smc1 or Smc3 subunit alone. We demonstrate that both h-Scc2/4 and h-cohesin are loaded onto dsDNA containing the prereplication complex (pre-RC) generated in vitro by Xenopus high-speed soluble extracts. The addition of geminin, which blocks pre-RC formation, prevents the loading of Scc2/4 and cohesin. Xenopus extracts depleted of endogenous Scc2/4 with specific antibodies, although able to form pre-RCs, did not support cohesin loading unless supplemented with purified h-Scc2/4. The results presented here indicate that the Xenopus or h-Scc2/4 complex supports the loading of Xenopus and/or h-cohesin onto pre-RCs formed by Xenopus high-speed extracts. We show that cohesin loaded onto pre-RCs either by h-Scc2/4 and/or the Xenopus complex was dissociated from chromatin by low salt extraction, similar to cohesin loaded onto chromatin in G(1) by HeLa cells in vivo. Replication of cohesin-loaded DNA, both in vitro and in vivo, markedly increased the stability of cohesin associated with DNA. Collectively, these in vitro findings partly recapitulate the in vivo pathway by which sister chromatids are linked together, leading to cohesion.
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Affiliation(s)
- Vladimir P. Bermudez
- Program in Molecular Biology, Memorial Sloan-Kettering Cancer Center, New York, NY 10065; and
| | - Andrea Farina
- Program in Molecular Biology, Memorial Sloan-Kettering Cancer Center, New York, NY 10065; and
| | | | - Fang Du
- Program in Molecular Biology, Memorial Sloan-Kettering Cancer Center, New York, NY 10065; and
| | - Inger Tappin
- Program in Molecular Biology, Memorial Sloan-Kettering Cancer Center, New York, NY 10065; and
| | | | - Jerard Hurwitz
- Program in Molecular Biology, Memorial Sloan-Kettering Cancer Center, New York, NY 10065; and
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194
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Higashi TL, Ikeda M, Tanaka H, Nakagawa T, Bando M, Shirahige K, Kubota Y, Takisawa H, Masukata H, Takahashi TS. The prereplication complex recruits XEco2 to chromatin to promote cohesin acetylation in Xenopus egg extracts. Curr Biol 2012; 22:977-88. [PMID: 22560615 DOI: 10.1016/j.cub.2012.04.013] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 03/08/2012] [Accepted: 04/04/2012] [Indexed: 01/31/2023]
Abstract
BACKGROUND Sister chromatids are held together by the ring-shaped cohesin complex, which is loaded onto chromosomes before DNA replication. Cohesion between sister chromosomes is established during DNA replication, and it requires acetylation of the Smc3 subunit of cohesin by evolutionally conserved cohesin acetyltransferases (CoATs). However, how CoATs are recruited to chromatin and how cohesin acetylation is regulated remain unclear. RESULTS We found that cohesin acetylation requires pre-RC-dependent chromatin loading of cohesin, but surprisingly, it is independent of DNA synthesis in Xenopus egg extracts. Immunodepletion experiments revealed that XEco2 is the CoAT responsible for Smc3 acetylation and sister chromatid cohesion. Recruitment of XEco2 onto chromatin was dependent on pre-RC assembly but was independent of cohesin loading and DNA synthesis. Two short N-terminal motifs, PBM-A and PBM-B, which are conserved among vertebrate Esco2/XEco2 homologs, were collectively essential for pre-RC-dependent chromatin association of XEco2, cohesin acetylation, and subsequent sister chromatid cohesion. The conserved PCNA-interacting protein box in XEco2 was largely dispensable for Smc3 acetylation but was partially required for cohesion. Interaction of acetylated cohesin with DNA was stabilized against salt-wash treatments after DNA replication. CONCLUSIONS Our results demonstrate that pre-RC formation regulates chromatin association of XEco2 in Xenopus egg extracts. We propose that this reaction is critical to acetylate cohesin, whose DNA binding is subsequently stabilized by DNA replication.
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Affiliation(s)
- Torahiko L Higashi
- Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan
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195
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Losing balance: the origin and impact of aneuploidy in cancer. EMBO Rep 2012; 13:501-14. [PMID: 22565320 DOI: 10.1038/embor.2012.55] [Citation(s) in RCA: 206] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Accepted: 04/03/2012] [Indexed: 02/06/2023] Open
Abstract
Most solid human tumours are aneuploid, that is, they contain an abnormal number of chromosomes. Paradoxically, however, aneuploidy has been reported to induce a stress response that suppresses cellular proliferation in vitro. Here, we review the progress in our understanding of the causes and effects of aneuploidy in cancer and discuss how, in specific contexts, aneuploidy can provide a growth advantage and facilitate cellular transformation. We also explore the emerging possibilities for targeting the cause or consequences of aneuploidy therapeutically.
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196
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Abstract
The maintenance of sister chromatid cohesion from S phase to the onset of anaphase relies on a small but evolutionarily conserved protein called Sororin. Sororin is a phosphoprotein and its dynamic localization and function are regulated by protein kinases, such as Cdk1/cyclin B and Erk2. The association of Sororin with chromatin requires cohesin to be preloaded to chromatin and modification of Smc3 during DNA replication. Sororin antagonizes the function of Wapl in cohesin releasing from S to G 2 phase and promotes cohesin release from sister chromatid arms in prophase via interaction with Plk1. This review focuses on progress of the identification and regulation of Sororin during cell cycle; role of post-translational modification on Sororin function; role of Sororin in the maintenance and resolution of sister chromatid cohesion; and finally discusses Sororin's emerging role in cancer and the potential issues that need be addressed in the future.
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Affiliation(s)
- Nenggang Zhang
- Texas Children’s Cancer Center; Department of Pediatric Hematology/Oncology; Baylor College of Medicine; Houston, TX USA
| | - Debananda Pati
- Texas Children’s Cancer Center; Department of Pediatric Hematology/Oncology; Baylor College of Medicine; Houston, TX USA
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197
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Jessberger R. Age-related aneuploidy through cohesion exhaustion. EMBO Rep 2012; 13:539-46. [PMID: 22565322 PMCID: PMC3367239 DOI: 10.1038/embor.2012.54] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Accepted: 03/29/2012] [Indexed: 11/08/2022] Open
Abstract
The trend of women to become pregnant when older than in previous generations poses a paramount medical problem, for oocytes are particularly prone to chromosome missegregation, and aneuploidy increases with age. Recent data strongly suggest that as oocyte age increases sister chromatid cohesion is weakened or lost. Cohesin deterioration seems to contribute significantly to age-dependent aneuploidy, as discussed in this review.
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Affiliation(s)
- Rolf Jessberger
- Institute of Physiological Chemistry, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Fiedlerstrasse 42, 01326 Dresden, Germany.
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198
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Watanabe Y. Geometry and force behind kinetochore orientation: lessons from meiosis. Nat Rev Mol Cell Biol 2012; 13:370-82. [PMID: 22588367 DOI: 10.1038/nrm3349] [Citation(s) in RCA: 133] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
During mitosis, replicated chromosomes (sister chromatids) become attached at the kinetochore by spindle microtubules emanating from opposite poles and segregate equationally. In the first division of meiosis, however, sister chromatids become attached from the same pole and co-segregate, whereas homologous chromosomes connected by chiasmata segregate to opposite poles. Disorder in this specialized chromosome attachment in meiosis is the leading cause of miscarriage in humans. Recent studies have elucidated the molecular mechanisms determining chromosome orientation, and consequently segregation, in meiosis. Comparative studies of meiosis and mitosis have led to the general principle that kinetochore geometry and tension exerted by microtubules synergistically generate chromosome orientation.
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Affiliation(s)
- Yoshinori Watanabe
- Laboratory of Chromosome Dynamics, Institute of Molecular and Cellular Biosciences, University of Tokyo, Yayoi, Tokyo 113-0032, Japan.
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199
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Abstract
The cohesin complex, named for its key role in sister chromatid cohesion, also plays critical roles in gene regulation and DNA repair. It performs all three functions in single cell eukaryotes such as yeasts, and in higher organisms such as man. Minor disruption of cohesin function has significant consequences for human development, even in the absence of measurable effects on chromatid cohesion or chromosome segregation. Here we survey the roles of cohesin in gene regulation and DNA repair, and how these functions vary from yeast to man.
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Affiliation(s)
- Dale Dorsett
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, Saint Louis, MO 63104, USA.
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Abstract
Stability and function of eukaryotic genomes are closely linked to chromatin structure and organization. During cell division the entire genome must be accurately replicated and the chromatin landscape reproduced on new DNA. Chromatin and nuclear structure influence where and when DNA replication initiates, whereas the replication process itself disrupts chromatin and challenges established patterns of genome regulation. Specialized replication-coupled mechanisms assemble new DNA into chromatin, but epigenome maintenance is a continuous process taking place throughout the cell cycle. If DNA synthesis is perturbed, cells can suffer loss of both genome and epigenome integrity with severe consequences for the organism.
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