Postreplicative Recruitment of Cohesin to Double-Strand Breaks Is Required for DNA Repair

Department of Cell and Molecular Biology, Karolinska Institute, Berzelius väg 35, 171 77 Stockholm, Sweden.
Molecular Cell (Impact Factor: 14.02). 01/2005; 16(6):1003-15. DOI: 10.1016/j.molcel.2004.11.026
Source: PubMed


Chromosome stability depends on accurate chromosome segregation and efficient DNA double-strand break (DSB) repair. Sister chromatid cohesion, established during S phase by the protein complex cohesin, is central to both processes. In the absence of cohesion, chromosomes missegregate and G2-phase DSB repair fails. Here, we demonstrate that G2-phase repair also requires the presence of cohesin at the damage site. Cohesin components are shown to be recruited to extended chromosome regions surrounding DNA breaks induced during G2. We find that in the absence of functional cohesin-loading proteins (Scc2/Scc4), the accumulation of cohesin at DSBs is abolished and repair is defective, even though sister chromatids are connected by S phase generated cohesion. Evidence is also provided that DSB induction elicits establishment of sister chromatid cohesion in G2, implicating that damage-recruited cohesin facilitates DNA repair by tethering chromatids.

Download full-text


Available from: Camilla Sjögren, Dec 14, 2013
21 Reads
  • Source
    • " so induces detachment of early S - phase kinetochore – microtubule attachments essential for cohesin - independent segregation ( Figure 2A ) . CPT inhibits topoisomerase I , which induces single - strand nicks that can become double - strand DNA breaks ( DSBs ) during replication in S phase . Because cohesin / cohesion play a role in DSB repair ( Ström et al . , 2004 ; Unal et al . , 2004 ) , CPT lethality is likely due to a combi - nation of reduced repair of DSBs and DNA - damage checkpoint – in - duced cell - cycle delays , increasing the likelihood of loss kineto - chore – microtubule attachments formed in S phase . We wanted to identify mutations that restore cohesion to eco1∆ wpl1∆ cells . We "
    [Show abstract] [Hide abstract]
    ABSTRACT: Cohesin complex mediates cohesion between sister chromatids, which promotes high fidelity chromosome segregation. Eco1p acetylates the cohesin subunit Smc3p during S phase to establish cohesion. The current model posits that this Eco1p mediated acetylation promotes establishment by abrogating the ability of Wpl1p to destabilize cohesin binding to chromosomes. Here, we present data from budding yeast that is incompatible with this Wpl1p-centric model. Two independent in vivo assays show that a wpl1∆ fails to suppress cohesion defects of eco1∆ cells. Moreover, a wpl1∆ also fails to suppress cohesion defects engendered by blocking just the essential Eco1p acetylation sites on Smc3p (K112,K113). Thus, removing WPL1 inhibition is insufficient for generating cohesion without ECO1 activity. To elucidate how ECO1 promotes cohesion, we conducted a genetic screen and identified a cohesion activator mutation in the SMC3 head domain (D1189H). Smc3-D1189H partially restores cohesion in eco1∆ wpl1∆ or eco1 mutant cells but robustly restores cohesion in cells blocked for Smc3p K112 K113 acetylation. These data support two important conclusions. First, acetylation of K112 K113 region by Eco1p promotes cohesion establishment by altering Smc3p head function independent of its ability to antagonize Wpl1p. Second, Eco1p targets other than Smc3p K112 K113 are necessary for efficient establishment.
    Molecular Biology of the Cell 11/2014; 26(1). DOI:10.1091/mbc.E14-08-1268 · 4.47 Impact Factor
  • Source
    • "In addition to its function in chromosome segregation, cohesin plays important roles in other nuclear processes including the DNA damage response and DNA repair (Kim et al, 2002; Yazdi et al, 2002; Strom et al, 2004; Unal et al, 2004; Watrin & Peters, 2009), chromatin organization and gene regulation. Cohesin facilitates transcriptional termination between convergent genes in yeast (Gullerova & Proudfoot, 2008) and controls the developmentally regulated expression of genes in multiple systems (Rollins et al, 2004; Horsfield et al, 2007; Landeira et al, 2009; Pauli et al, 2010). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Sister chromatid cohesion mediated by the cohesin complex is essential for chromosome segregation during cell division. Using functional genomic screening, we identify a set of 26 pre-mRNA splicing factors that are required for sister chromatid cohesion in human cells. Loss of spliceosome subunits increases the dissociation rate of cohesin from chromatin and abrogates cohesion after DNA replication, ultimately causing mitotic catastrophe. Depletion of splicing factors causes defective processing of the pre-mRNA encoding sororin, a factor required for the stable association of cohesin with chromatin, and an associated reduction of sororin protein level. Expression of an intronless version of sororin and depletion of the cohesin release protein WAPL suppress the cohesion defect in cells lacking splicing factors. We propose that spliceosome components contribute to sister chromatid cohesion and mitotic chromosome segregation through splicing of sororin pre-mRNA. Our results highlight the loss of cohesion as an early cellular consequence of compromised splicing. This may have clinical implications because SF3B1, a splicing factor that we identify to be essential for cohesion, is recurrently mutated in chronic lymphocytic leukaemia.
    The EMBO Journal 09/2014; 33(22). DOI:10.15252/embj.201488244 · 10.43 Impact Factor
  • Source
    • "Cohesin and condensin also function in DNA repair (Wu and Yu 2012). Cohesin is recruited to sites of DNA DSBs to facilitate HR through sister-chromatid cohesion and to elicit an efficient DNA damage checkpoint response (Kim et al. 2002; Ström et al. 2004; Unal et al. 2004). Condensin is implicated in repair of single- and double-strand breaks and in ribosomal DNA stability (Aono et al. 2002; Heale et al. 2006; Tsang et al. 2007; Wood et al. 2008). "
    [Show abstract] [Hide abstract]
    ABSTRACT: DNA damage by ultraviolet (UV) light poses a risk for mutagenesis and a potential hindrance for cell cycle progression. Cells cope with UV-induced DNA damage through two general strategies to repair the damaged nucleotides and to promote cell cycle progression in the presence of UV-damaged DNA. Defining the genetic pathways and understanding how they function together to enable effective tolerance to UV remains an important area of research. The Structural Maintenance of Chromosomes (SMC) proteins form distinct complexes that maintain genome stability during chromosome segregation, homologous recombination, and DNA replication. Using a forward genetic screen, we identified two alleles of smc-5 that exacerbate UV sensitivity in Caenorhabditis elegans. Germ cells of smc-5 defective animals show reduced proliferation, sensitivity to perturbed replication, chromatin bridge formation, and accumulation of RAD-51 foci that indicate the activation of homologous recombination at DNA double-strand breaks. Mutations in the translesion synthesis polymerase polh-1 act synergistically with smc-5 mutations in provoking genome instability after UV-induced DNA damage. In contrast, the DNA damage accumulation and sensitivity of smc-5 mutant strains to replication impediments are suppressed by mutations in the C. elegans BRCA1/BARD1 homologs, brc-1 and brd-1. We propose that SMC-5/6 promotes replication fork stability and facilitates recombination-dependent repair when the BRC-1/BRD-1 complex initiates HR at stalled replication forks. Our data suggest that BRC-1/BRD-1 can both promote and antagonize genome stability depending on whether homologous recombination is initiated during DNA double-strand break repair or during replication stalling.
    Genetics 01/2014; 196(4). DOI:10.1534/genetics.113.158295 · 5.96 Impact Factor
Show more