Histone chaperone NAP1 mediates sister chromatid resolution by counteracting protein phosphatase 2A.
Ontology highlight
ABSTRACT:
SUBMITTER: Moshkin YM
PROVIDER: S-EPMC3784504 | biostudies-literature | 2013
REPOSITORIES: biostudies-literature
Publications
Histone chaperone NAP1 mediates sister chromatid resolution by counteracting protein phosphatase 2A.
Moshkin Yuri M YM Doyen Cecile M CM Kan Tsung-Wai TW Chalkley Gillian E GE Sap Karen K Bezstarosti Karel K Demmers Jeroen A JA Ozgur Zeliha Z van Ijcken Wilfred F J WF Verrijzer C Peter CP
PLoS genetics 20130926 9
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 cohesi ...[more]
Similar Datasets
Project description:The fidelity of chromosome duplication through cell divisions requires timely binding and release of the cohesin. Cohesin is a ring-shaped protein complex linking newly replicated sister chromatids to ensure their appropriate transmission through mitosis. Upon commencement of mitosis cohesin is removed from DNA in two steps: first, from chromosome arms resulting in sister chromatid resolution, and, second, from centromers leading to sister chromatid segregation. As DNA of eukaryotic chromosomes is assembled into chromatin, regulation of sister chromatid cohesion-segregation may involve chromatin modifying machinery, but this link is not well understood. Here we report that H2A-H2B histone chaperone NAP1, a factor, which is primarily implicated in chromatin assembly, is required for cohesin release from mitotic chromosome arms. NAP1 and cohesin protein complex interact directly and share multiple binding sites on chromatin. Depletion of the NAP1 hinders cohesin removal during mitosis resulting in accumulation of unresolved sister chromatids. Thus, in addition to its well established functions in chromatin dynamics, histone chaperone NAP1 coordinates cell cycle dependent cohesin release. These results reveal a novel molecular pathway for sister chromatid resolution and emphasizes a role for histone chaperones in control of eukaryotic genome replication and transmission. Genome-wide NAP1 and Cohesin ChIP-chip profiling in Drosophila S2 cells. The supplementary bed file S2_cohesin_sites.bed contains cohesin binding sites obtained by intersecting the sets of significant ChIP-chip peaks for SA (a cohesin subunit; stromalin) and SMC1.
2012-07-25 | E-GEOD-30938 | biostudies-arrayexpress
Project description:The fidelity of chromosome duplication through cell divisions requires timely binding and release of the cohesin. Cohesin is a ring-shaped protein complex linking newly replicated sister chromatids to ensure their appropriate transmission through mitosis. Upon commencement of mitosis cohesin is removed from DNA in two steps: first, from chromosome arms resulting in sister chromatid resolution, and, second, from centromers leading to sister chromatid segregation. As DNA of eukaryotic chromosomes is assembled into chromatin, regulation of sister chromatid cohesion-segregation may involve chromatin modifying machinery, but this link is not well understood. Here we report that H2A-H2B histone chaperone NAP1, a factor, which is primarily implicated in chromatin assembly, is required for cohesin release from mitotic chromosome arms. NAP1 and cohesin protein complex interact directly and share multiple binding sites on chromatin. Depletion of the NAP1 hinders cohesin removal during mitosis resulting in accumulation of unresolved sister chromatids. Thus, in addition to its well established functions in chromatin dynamics, histone chaperone NAP1 coordinates cell cycle dependent cohesin release. These results reveal a novel molecular pathway for sister chromatid resolution and emphasizes a role for histone chaperones in control of eukaryotic genome replication and transmission.
2012-07-26 | GSE30938 | GEO
Project description:Segregation of homologous maternal and paternal centromeres to opposite poles during meiosis I depends on post-replicative crossing over between homologous non-sister chromatids, which creates chiasmata and therefore bivalent chromosomes. Destruction of sister chromatid cohesion along chromosome arms due to proteolytic cleavage of cohesin's Rec8 subunit by separase resolves chiasmata and thereby triggers the first meiotic division. This produces univalent chromosomes, the chromatids of which are held together by centromeric cohesin that has been protected from separase by shugoshin (Sgo1/MEI-S332) proteins. Here we show in both fission and budding yeast that Sgo1 recruits to centromeres a specific form of protein phosphatase 2A (PP2A). Its inactivation causes loss of centromeric cohesin at anaphase I and random segregation of sister centromeres at the second meiotic division. Artificial recruitment of PP2A to chromosome arms prevents Rec8 phosphorylation and hinders resolution of chiasmata. Our data are consistent with the notion that efficient cleavage of Rec8 requires phosphorylation of cohesin and that this is blocked by PP2A at meiosis I centromeres. Keywords: ChIP-chip, Mitosis, Meiosis, Cell cycle, Saccharomyces cerevisiae, Chromosome VI tiling array, Sgo1, Pp2A, Cse4, Ndc10, Rts1, Rec8
2006-05-10 | GSE4791 | GEO
Project description:Segregation of homologous maternal and paternal centromeres to opposite poles during meiosis I depends on post-replicative crossing over between homologous non-sister chromatids, which creates chiasmata and therefore bivalent chromosomes. Destruction of sister chromatid cohesion along chromosome arms due to proteolytic cleavage of cohesin's Rec8 subunit by separase resolves chiasmata and thereby triggers the first meiotic division. This produces univalent chromosomes, the chromatids of which are held together by centromeric cohesin that has been protected from separase by shugoshin (Sgo1/MEI-S332) proteins. Here we show in both fission and budding yeast that Sgo1 recruits to centromeres a specific form of protein phosphatase 2A (PP2A). Its inactivation causes loss of centromeric cohesin at anaphase I and random segregation of sister centromeres at the second meiotic division. Artificial recruitment of PP2A to chromosome arms prevents Rec8 phosphorylation and hinders resolution of chiasmata. Our data are consistent with the notion that efficient cleavage of Rec8 requires phosphorylation of cohesin and that this is blocked by PP2A at meiosis I centromeres. Keywords: ChIP-chip, Mitosis, Meiosis, Cell cycle, Saccharomyces cerevisiae, Chromosome VI tiling array, Sgo1, Pp2A, Cse4, Ndc10, Rts1, Rec8 â?¢ Experimental factors Distribution of Cse4, Ndc10, Rts1 in mitotic G2 phase and meiosis I (S. cerevisiae). Distribution of Rec8 in meiosis I (S.cerevisiae). All experiments were performed in cells with the same genetic background (Saccharomyces cerevisiae SK1). â?¢ Experimental design ChIP analysis: In all cases, hybridization data for ChIP fraction was compared with SUP (supernatant) fraction. SUP fraction is same as WCE fraction. â?¢ Quality control steps taken Duplication, confirmation using different tags, and different subunits of the same complex. Confirmation of protein distribution using deletion mutant strain. Confirmation of several loci by q-PCR. Checking of the ChIP fraction by Western blotting. Checking of the ChIP fraction by swapping SUP fraction. Samples used, extract preparation and labelling: â?¢ The origin of each biological sample Saccharomyces cerevisiae (SK1) . â?¢ Manipulation of biological samples and protocols used Chromatin immunoprecipitation (ChIP) and hybridization to Affimetrix high-density oligonucleotide arrays of S. cerevisiae chromosome VI was performed essentially as previously described (Katou et al., 2003, nature) (Lengronne et al., 2004, nature). â?¢ Technical protocols for preparing the hybridization extract The chromatin-immunprecipates were eluted and incubated over night at 65ºC to reverse the cross-link. Immunoprecipitated genomic DNA was incubated with proteinase K, extracted 2 times with phenol/chloroform/isoamylalcohol, precipitated, resuspended in TE and incubated with RnaseA. The DNA was then purified using the Qiagen PCR purification kit, and concentrated by ethanol precipitation. The DNA was amplified by PCR after random priming. 10 ug of amplified DNA was digested with Dnase I to a mean size of 100 bp. After Dnase I inactivation at 95ºC. DNA fragments were end-labeled by addition of 25 U of Terminal Transferase and 1 nmol Biotin-N6ddATP (NEN) for 1 hour at 37ºC as previously described by Winzeler et al. (Science. 281, 1194-1197, 1998). The entire sample was used for hybridization. â?¢ Hybridization procedures and parameters: Hybridization, blocking and washing were carried out as previously described (http://everythingchromosomevi.gsc.riken.go.jp). Each sample was hybridized to the array in 150 ul containing 6xSSPE; 0.005% TritonX-100; 15 ug fragmented denatured salmon sperm DNA (Gibco-BRL); 1 nmole 3â??biotin labelled control oligonucleotide (oligo B2, Affymetrix). Samples were denatured at 100ºC for 10 minutes, and then put on ice before being hybridized for 16 hours at 42ºC in a hybridization oven (GeneChip Hybridization Oven 640, Affymetrix). Washing and scanning protocol provided by Affymetrix was performed automatically on a fluidics station (GeneChip fluidics station 450, Affymetrix). â?¢ Measurement data and specifications: Arrays were scanned using the Genechip Scanner3000 7G following the library array description. All the raw data files can be downloaded from GEO database. The primary analysis of tiling chip data was performed following exactly the statistical algorithm used for Affymetrix GeneChip Operating Software (GCOS). The detailed information for the algorithm used can be downloaded from the Affymetrix web site at http://www.affymetrix.com/support/technical/technotes/statistical_reference_guide.pdf. The analysis is available on request. For the ChrVI array, one unit for analysis (locus) was set to 300bp. Fold change value, change p-value, and detection p-value for each locus were obtained by primary analysis. For the discrimination of positive and negative signals for the binding, we used three criteria as follows. First, the reliability of the signal strength was judged by detection p-value of each locus (p-valueâ?¤0.025 for cerevisiae). Secondly, reliability of binding ratio was judged by change p-value (p-valueâ?¤0.025 for cerevisiae). Thirdly, clusters consisting of at least 900bp contiguous loci that satisfied the above two criteria were selected, because it is known that a single site of protein-DNA interaction resulted in immuno-precipitation of DNA fragments that hybridized not only to the locus of the actual binding site but also to its neighbors. â?¢ Array Design: General array design: in situ synthesized arrays by Affymetrix Availability of arrays: commercially available from Affymetrix Location and ID of each spot on arrays: available from Affymetrix on request Probe type: oligonucleotide The arrays used in this study can be purchased from Affymetrix: Chromosome VI S.cerevisiae: rikDACFC6, P/N# 510636
2010-06-11 | E-GEOD-4791 | biostudies-arrayexpress
Project description:Spindle disruption or DNA damage prevents sister chromatid separation through the activation of checkpoint pathways that inhibit anaphase entry by stabilizing the anaphase inhibitor Pds1. Mutation of CDC55, which encodes a B regulatory subunit of protein phosphatase 2A (PP2A), results in precocious sister chromatid separation when spindle is disrupted. Here we report that decreased Pds1 levels in Deltacdc55 mutants contribute to sister chromatid separation in the presence of nocodazole, a microtubule-depolymerizing drug. However, in the presence of DNA damage, Deltacdc55 mutant cells separate sister chromatids without noticeable decrease of Pds1 or cohesin Mcd1/Scc1 levels. Further analysis demonstrates that Deltacdc55 mutants lose cohesion along the entire chromosomes when the spindle is disrupted. In contrast, separation of sister chromatids is limited to the centromeric regions in Deltacdc55 cells after DNA damage. Moreover, mutation of TPD3, which encodes the A regulatory subunit of PP2A, also results in sister chromatid separation in DNA- or spindle-damage-arrested cells. These data suggest that PP2A regulates sister chromatid cohesion in Pds1-dependent and -independent manners.
| S-EPMC1637575 | biostudies-literature
Project description:Histone H2AX has a role in suppressing genomic instability and cancer. However, the mechanisms by which it performs these functions are poorly understood. After DNA breakage, H2AX is phosphorylated on serine 139 in chromatin near the break. We show here that H2AX serine 139 enforces efficient homologous recombinational repair of a chromosomal double-strand break (DSB) by using the sister chromatid as a template. BRCA1, Rad51, and CHK2 contribute to recombinational repair, in part independently of H2AX. H2AX(-/-) cells show increased use of single-strand annealing, an error-prone deletional mechanism of DSB repair. Therefore, the chromatin response around a chromosomal DSB, in which H2AX serine 139 phosphorylation plays a central role, "shapes" the repair process in favor of potentially error-free interchromatid homologous recombination at the expense of error-prone repair. H2AX phosphorylation may help set up a favorable disposition between sister chromatids.
| S-EPMC2991138 | biostudies-literature
Project description:Cohesin is a multiprotein complex that establishes sister chromatid cohesion from S phase until mitosis or meiosis. In vertebrates, sister chromatid cohesion is dissolved in a stepwise manner: most cohesins are removed from the chromosome arms via a process that requires polo-like kinase 1 (Plk1), aurora B and Wapl, whereas a minor amount of cohesin, found preferentially at the centromere, is cleaved by separase following its activation by the anaphase-promoting complex/cyclosome. Here, we report that our budding yeast two-hybrid assay identified hsSsu72 phosphatase as a Rad21-binding protein. Additional experiments revealed that Ssu72 directly interacts with Rad21 and SA2 in vitro and in vivo, and associates with sister chromatids in human cells. Interestingly, depletion or mutational inactivation of Ssu72 phosphatase activity caused the premature resolution of sister chromatid arm cohesion, whereas the overexpression of Ssu72 yielded high resistance to this resolution. Interestingly, it appears that Ssu72 regulates the cohesion of chromosome arms but not centromeres, and acts by counteracting the phosphorylation of SA2. Thus, our study provides important new evidence, suggesting that Ssu72 is a novel cohesin-binding protein capable of regulating cohesion between sister chromatid arms.
| S-EPMC2964166 | biostudies-literature
Project description:Faithful genome transmission in dividing cells requires that the two copies of each chromosome's DNA package into separate but physically linked sister chromatids. The linkage between sister chromatids is mediated by cohesin, yet where sister chromatids are linked and how they resolve during cell cycle progression has remained unclear. In this study, we investigated sister chromatid organization in live human cells using dCas9-mEGFP labeling of endogenous genomic loci. We detected substantial sister locus separation during G2 phase irrespective of the proximity to cohesin enrichment sites. Almost all sister loci separated within a few hours after their respective replication and then rapidly equilibrated their average distances within dynamic chromatin polymers. Our findings explain why the topology of sister chromatid resolution in G2 largely reflects the DNA replication program. Furthermore, these data suggest that cohesin enrichment sites are not persistent cohesive sites in human cells. Rather, cohesion might occur at variable genomic positions within the cell population.
| S-EPMC5987726 | biostudies-literature
Project description:Condensins I and II are multisubunit complexes that play essential yet distinct functions in chromosome condensation and segregation in mitosis. Unlike condensin I, condensin II localizes to the nucleus during interphase, but it remains poorly understood what functions condensin II might have before mitotic entry. Here, we report that condensin II changes its chromatin-binding property during S phase. Remarkably, advanced premature chromosome condensation (PCC) assays enabled us to visualize condensin II forming "sister axes" in replicated regions of chromosomes in S phase cells. Depletion of condensin II compromised PCC-driven sister chromatid resolution during S phase. Moreover, fluorescence in situ hybridization assays revealed that condensin II, but not condensin I, promotes disjoining duplicated chromosomal loci during S phase. Application of mild replicative stress partially impaired this process and further exacerbated phenotypes arising from condensin II depletion. Our results suggest that condensin II initiates structural reorganization of duplicated chromosomes during S phase to prepare for their proper condensation and segregation in mitosis.
| S-EPMC3575537 | biostudies-literature
Project description:The organization of the eukaryotic genome into nucleosomes dramatically affects the regulation of gene expression. The delicate balance between transcription and DNA compaction relies heavily on nucleosome dynamics. Surprisingly, little is known about the free energy required to assemble these large macromolecular complexes and maintain them under physiological conditions. Here, we describe the thermodynamic parameters that drive nucleosome formation in vitro. To demonstrate the versatility of our approach, we test the effect of DNA sequence and H3K56 acetylation on nucleosome thermodynamics. Furthermore, our studies reveal the mechanism of action of the histone chaperone nucleosome assembly protein 1 (Nap1). We present evidence for a paradigm in which nucleosome assembly requires the elimination of competing, nonnucleosomal histone-DNA interactions by Nap1. This observation is confirmed in vivo, wherein deletion of the NAP1 gene in yeast results in a significant increase in atypical histone-DNA complexes, as well as in deregulated transcription activation and repression.
| S-EPMC2880918 | biostudies-literature