scholarly journals Dynamics of sister chromatids through the cell cycle: Together and apart

2018 ◽  
Vol 217 (6) ◽  
pp. 1887-1889 ◽  
Author(s):  
Motoko Takahashi ◽  
Toru Hirota
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Sister Chromatid ◽  
Fundamental Question ◽  
Live Cells ◽  
Sister Chromatids ◽  
Cell Biol

When and how sister chromatid resolution occurs after DNA replication is a fundamental question. Stanyte et al. (2018. J. Cell Biol. https://doi.org/10.1083/jcb.201801157) used CRISPR/Cas9 technology to label and track genomic loci in live cells throughout the cell cycle, shedding light on how replication is linked to mitotic sister chromatid organization.

PATTERN OF SEGREGATION OF LABELED DNA AT THE CHROMATID LEVEL OF CHROMOSOMES WITH DIFFUSE CENTROMERES

1969 ◽  
Vol 11 (4) ◽  
pp. 928-936 ◽  
Author(s):  
Janet S. R. Nelson
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Sister Chromatid ◽  
Cycle Time ◽  
Full Length ◽  
Sister Chromatids ◽  
Labeling Pattern ◽  
Shoot Meristems

After pulse labeling Luzula purpurea shoot meristems with3H-thymidine, the cell cycle and its subdivisions were determined autoradiographically using the labeled mitoses method. The cycle time was 20 hr. G1 = 4.3 hr; C = 9.5 hr; G2 = 2.9 hr; and M = 3.3 hr. In subsequent experiments seedlings were labeled for 4 to 5 hr, long enough to label the chromosomes' full length, eliminating problems associated with asynchronous DNA replication. The longer labeling period did not alter the cell cycle parameters.Cells were designated as being in the first or second division after labeling by the time from the midpoint of the labeling period. Seedlings were placed in 0.1% cycloheximide solution to cause sister chromatids in metaphase cells to separate from each other. Autoradiographs were then made to determine segregation of labeled DNA at the chromatid level. At the first division after labeling all chromatids appeared to be labeled. At the second division after labeling with 3H-thymidine the labeling pattern was consistent with semiconservative segregation of labeled DNA and with sister chromatid exchange.These results are discussed in relation to cytological and photometric studies on chromosome strandedness in Luzula and in other organisms with chromosomes with diffuse centromeres.

scholarly journals Dynamics of sister chromatid resolution during cell cycle progression

2018 ◽  
Author(s):  
Rugile Stanyte ◽  
Johannes Nuebler ◽  
Claudia Blaukopf ◽  
Rudolf Hoefler ◽  
Roman Stocsits ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Sister Chromatid ◽  
Cell Cycle Progression ◽  
Human Cells ◽  
Cycle Progression ◽  
Sister Chromatids ◽  
Dividing Cells ◽  
G2 Phase ◽  
Almost All

Faithful genome transmission in dividing cells requires that the two copies of each chromosome’s DNA package into separate, but physically linked, sister chromatids. The linkage between sister chromatids is mediated by cohesin, yet where sister chromatids are linked and how they resolve during cell cycle progression has remained unclear. Here, we investigated sister chromatid organization in live human cells using dCas9-mEGFP labelling of endogenous genomic loci. We detected substantial sister locus separation during G2 phase, irrespective of the proximity to cohesin enrichment sites. Almost all sister loci separated within a few hours after their respective replication, and then rapidly equilibrated their average distances within dynamic chromatin polymers. Our findings explain why the topology of sister chromatid resolution in G2 largely reflects the DNA replication program. Further, these data suggest that cohesin enrichment sites are not persistent cohesive sites in human cells. Rather, cohesion might occur at variable genomic positions within the cell population.

scholarly journals Dynamics of sister chromatid resolution during cell cycle progression

2018 ◽  
Vol 217 (6) ◽  
pp. 1985-2004 ◽  
Author(s):  
Rugile Stanyte ◽  
Johannes Nuebler ◽  
Claudia Blaukopf ◽  
Rudolf Hoefler ◽  
Roman Stocsits ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Sister Chromatid ◽  
Cell Cycle Progression ◽  
Human Cells ◽  
Cycle Progression ◽  
Sister Chromatids ◽  
Dividing Cells ◽  
G2 Phase ◽  
Almost All

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.

scholarly journals Correct spindle elongation at the metaphase/anaphase transition is an APC-dependent event in budding yeast

2001 ◽  
Vol 155 (5) ◽  
pp. 711-718 ◽  
Author(s):  
Fedor Severin ◽  
Anthony A. Hyman ◽  
Simonetta Piatti
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Chromosome Segregation ◽  
Sister Chromatid ◽  
Budding Yeast ◽  
Sister Chromatid Cohesion ◽  
Anaphase Promoting Complex ◽  
Sister Chromatids ◽  
Chromatid Cohesion ◽  
Spindle Elongation

At the metaphase to anaphase transition, chromosome segregation is initiated by the splitting of sister chromatids. Subsequently, spindles elongate, separating the sister chromosomes into two sets. Here, we investigate the cell cycle requirements for spindle elongation in budding yeast using mutants affecting sister chromatid cohesion or DNA replication. We show that separation of sister chromatids is not sufficient for proper spindle integrity during elongation. Rather, successful spindle elongation and stability require both sister chromatid separation and anaphase-promoting complex activation. Spindle integrity during elongation is dependent on proteolysis of the securin Pds1 but not on the activity of the separase Esp1. Our data suggest that stabilization of the elongating spindle at the metaphase to anaphase transition involves Pds1-dependent targets other than Esp1.

scholarly journals Multivalent interaction of ESCO2 with the replication machinery is required for sister chromatid cohesion in vertebrates

2019 ◽  
Vol 117 (2) ◽  
pp. 1081-1089 ◽  
Author(s):  
Dawn Bender ◽  
Eulália Maria Lima Da Silva ◽  
Jingrong Chen ◽  
Annelise Poss ◽  
Lauren Gawey ◽  
...  
Keyword(s):  
Dna Replication ◽  
Sister Chromatid ◽  
Sister Chromatid Cohesion ◽  
Replication Machinery ◽  
Replicative Helicase ◽  
Sister Chromatids ◽  
Chromatid Cohesion ◽  
N Terminus ◽  
Mcm Complex ◽  
Unique Ability

The tethering together of sister chromatids by the cohesin complex ensures their accurate alignment and segregation during cell division. In vertebrates, sister chromatid cohesion requires the activity of the ESCO2 acetyltransferase, which modifies the Smc3 subunit of cohesin. It was shown recently that ESCO2 promotes cohesion through interaction with the MCM replicative helicase. However, ESCO2 does not significantly colocalize with the MCM complex, suggesting there are additional interactions important for ESCO2 function. Here we show that ESCO2 is recruited to replication factories, sites of DNA replication, through interaction with PCNA. We show that ESCO2 contains multiple PCNA-interaction motifs in its N terminus, each of which is essential to its ability to establish cohesion. We propose that multiple PCNA-interaction motifs embedded in a largely flexible and disordered region of the protein underlie the unique ability of ESCO2 to establish cohesion between sister chromatids precisely as they are born during DNA replication.

scholarly journals Astrin is required for the maintenance of sister chromatid cohesion and centrosome integrity

2007 ◽  
Vol 178 (3) ◽  
pp. 345-354 ◽  
Author(s):  
Kerstin H. Thein ◽  
Julia Kleylein-Sohn ◽  
Erich A. Nigg ◽  
Ulrike Gruneberg
Keyword(s):  
Cell Cycle ◽  
Chromosome Segregation ◽  
Sister Chromatid ◽  
Cysteine Protease ◽  
Mitotic Spindle ◽  
Regulatory Network ◽  
Successful Completion ◽  
Sister Chromatids ◽  
Multipolar Spindles ◽  
Chromatid Cohesion

Faithful chromosome segregation in mitosis requires the formation of a bipolar mitotic spindle with stably attached chromosomes. Once all of the chromosomes are aligned, the connection between the sister chromatids is severed by the cysteine protease separase. Separase also promotes centriole disengagement at the end of mitosis. Temporal coordination of these two activities with the rest of the cell cycle is required for the successful completion of mitosis. In this study, we report that depletion of the microtubule and kinetochore protein astrin results in checkpoint-arrested cells with multipolar spindles and separated sister chromatids, which is consistent with untimely separase activation. Supporting this idea, astrin-depleted cells contain active separase, and separase depletion suppresses the premature sister chromatid separation and centriole disengagement in these cells. We suggest that astrin contributes to the regulatory network that controls separase activity.

scholarly journals The Interplay of Cohesin and the Replisome at Processive and Stressed DNA Replication Forks

Cells ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3455
Author(s):  
Janne J.M. van Schie ◽  
Job de Lange
Keyword(s):  
Dna Replication ◽  
Sister Chromatid ◽  
Molecular Mechanisms ◽  
Replication Stress ◽  
Sister Chromatid Cohesion ◽  
Key Factors ◽  
Sister Chromatids ◽  
Chromatid Cohesion ◽  
Dna Replication Stress ◽  
Subsequent Stabilization

The cohesin complex facilitates faithful chromosome segregation by pairing the sister chromatids after DNA replication until mitosis. In addition, cohesin contributes to proficient and error-free DNA replication. Replisome progression and establishment of sister chromatid cohesion are intimately intertwined processes. Here, we review how the key factors in DNA replication and cohesion establishment cooperate in unperturbed conditions and during DNA replication stress. We discuss the detailed molecular mechanisms of cohesin recruitment and the entrapment of replicated sister chromatids at the replisome, the subsequent stabilization of sister chromatid cohesion via SMC3 acetylation, as well as the role and regulation of cohesin in the response to DNA replication stress.

scholarly journals Brca2, Pds5 and Wapl differentially control cohesin chromosome association and function

2017 ◽  
Author(s):  
Ziva Misulovin ◽  
Michelle Pherson ◽  
Maria Gause ◽  
Dale Dorsett
Keyword(s):  
Gene Expression ◽  
Dna Repair ◽  
Dna Replication ◽  
Chromosome Segregation ◽  
Sister Chromatid ◽  
Protein Complex ◽  
Sister Chromatid Cohesion ◽  
Sister Chromatids ◽  
Chromatid Cohesion ◽  
Active Genes

AbstractThe cohesin complex topologically encircles chromosomes and mediates sister chromatid cohesion to ensure accurate chromosome segregation upon cell division. Cohesin also participates in DNA repair and gene transcription. The Nipped-B – Mau2 protein complex loads cohesin onto chromosomes and the Pds5 - Wapl complex removes cohesin. Pds5 is also essential for sister chromatid cohesion, indicating that it has functions beyond cohesin removal. The Brca2 DNA repair protein interacts with Pds5, but the roles of this complex beyond DNA repair are unknown. Here we show that Brca2 opposes Pds5 function in sister chromatid cohesion by assaying precocious sister chromatid separation in metaphase spreads of cultured cells depleted for these proteins. By genome-wide chromatin immunoprecipitation we find that Pds5 facilitates SA cohesin subunit association with DNA replication origins and that Brca2 inhibits SA binding, mirroring their effects on sister chromatid cohesion. Cohesin binding is maximal at replication origins and extends outward to occupy active genes and regulatory sequences. Pds5 and Wapl, but not Brca2, limit the distance that cohesin extends from origins, thereby determining which active genes, enhancers and silencers bind cohesin. Using RNA-seq we find that Brca2, Pds5 and Wapl influence the expression of most genes sensitive to Nipped-B and cohesin, largely in the same direction. These findings demonstrate that Brca2 regulates sister chromatid cohesion and gene expression in addition to its canonical role in DNA repair and expand the known functions of accessory proteins in cohesin’s diverse functions.Author summaryThe cohesin protein complex has multiple functions in eukaryotic cells. It ensures that when a cell divides, the two daughter cells receive the correct number of chromosomes. It does this by holding together the sister chromatids that are formed when chromosomes are duplicated by DNA replication. Cohesin also helps repair damaged DNA, and to regulate genes important for growth and development. Even minor deficiencies in some proteins that regulate cohesin cause significant human birth defects. Here we investigated in Drosophila cells how three proteins, Pds5, Wapl and Brca2, determine where cohesin binds to chromosomes, control cohesin’s ability to hold sister chromatids together, and participate in gene expression. We find that Pds5 and Wapl work together, likely during DNA replication, to determine which genes bind cohesin by controlling how far cohesin spreads out along chromosomes. Pds5 is required for cohesin to hold sister chromatids together, and Brca2 counteracts this function. In contrast to the opposing roles in sister chromatid cohesion, Pds5 and Brca2 work together to facilitate control of gene expression by cohesin. Brca2 plays a critical role in DNA repair, and these studies expand the known roles for Brca2 by showing that it also regulates sister chromatid cohesion and gene expression. BRCA2 mutations in humans increase susceptibility to breast and ovarian cancer, and these findings raise the possibility that changes in chromosome segregation or gene expression might contribute to the increased cancer risk associated with these mutations.

scholarly journals Replication-dependent sister chromatid recombination in rad1 mutants of Saccharomyces cerevisiae.

Genetics ◽  
1993 ◽  
Vol 133 (3) ◽  
pp. 469-487 ◽  
Author(s):  
L C Kadyk ◽  
L H Hartwell
Keyword(s):  
Dna Replication ◽  
Gene Conversion ◽  
Uv Irradiation ◽  
Sister Chromatid ◽  
Mammalian Cells ◽  
Excision Repair ◽  
Yeast Cells ◽  
Sister Chromatids ◽  
X Irradiation ◽  
Sister Chromatid Recombination

Abstract Homolog recombination and unequal sister chromatid recombination were monitored in rad1-1/rad1-1 diploid yeast cells deficient for excision repair, and in control cells, RAD1/rad1-1, after exposure to UV irradiation. In a rad1-1/rad1-1 diploid, UV irradiation stimulated much more sister chromatid recombination relative to homolog recombination when cells were irradiated in the G1 or the G2 phases of the cell cycle than was observed in RAD1/rad1-1 cells. Since sister chromatids are not present during G1, this result suggested that unexcised lesions can stimulate sister chromatid recombination events during or subsequent to DNA replication. The results of mating rescue experiments suggest that unexcised UV dimers do not stimulate sister chromatid recombination during the G2 phase, but only when they are present during DNA replication. We propose that there are two types of sister chromatid recombination in yeast. In the first type, unexcised UV dimers and other bulky lesions induce sister chromatid recombination during DNA replication as a mechanism to bypass lesions obstructing the passage of DNA polymerase, and this type is analogous to the type of sister chromatid exchange commonly observed cytologically in mammalian cells. In the second type, strand scissions created by X-irradiation or the excision of damaged bases create recombinogenic sites that result in sister chromatid recombination directly in G2. Further support for the existence of two types of sister chromatid recombination is the fact that events induced in rad1-1/rad1-1 were due almost entirely to gene conversion, whereas those in RAD1/rad1-1 cells were due to a mixture of gene conversion and reciprocal recombination.

Centromere assembly and non-random sister chromatid segregation in stem cells

2020 ◽  
Vol 64 (2) ◽  
pp. 223-232 ◽  
Author(s):  
Ben L. Carty ◽  
Elaine M. Dunleavy
Keyword(s):  
Stem Cells ◽  
Cell Division ◽  
Cell Fate ◽  
Sister Chromatid ◽  
Asymmetric Cell Division ◽  
Protein A ◽  
Germline Stem Cells ◽  
Sister Chromatids ◽  
Centromere Protein A ◽  
Oocyte Meiosis

Abstract Asymmetric cell division (ACD) produces daughter cells with separate distinct cell fates and is critical for the development and regulation of multicellular organisms. Epigenetic mechanisms are key players in cell fate determination. Centromeres, epigenetically specified loci defined by the presence of the histone H3-variant, centromere protein A (CENP-A), are essential for chromosome segregation at cell division. ACDs in stem cells and in oocyte meiosis have been proposed to be reliant on centromere integrity for the regulation of the non-random segregation of chromosomes. It has recently been shown that CENP-A is asymmetrically distributed between the centromeres of sister chromatids in male and female Drosophila germline stem cells (GSCs), with more CENP-A on sister chromatids to be segregated to the GSC. This imbalance in centromere strength correlates with the temporal and asymmetric assembly of the mitotic spindle and potentially orientates the cell to allow for biased sister chromatid retention in stem cells. In this essay, we discuss the recent evidence for asymmetric sister centromeres in stem cells. Thereafter, we discuss mechanistic avenues to establish this sister centromere asymmetry and how it ultimately might influence cell fate.

Sign in / Sign up

Export Citation Format

Share Document