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Postreplicative Formation of Cohesion Is Required for Repair and Induced by a Single DNA Break
Lena Ström,1
Charlotte Karlsson,1
Hanna Betts Lindroos,1
Sara Wedahl,1
Yuki Katou,2
Katsuhiko Shirahige,2
Camilla Sjögren1*
Abstract:
Sister-chromatid cohesion, established during replication bythe protein complex cohesin, is essential for both chromosomesegregation and double-strand break (DSB) repair. Normally,cohesion formation is strictly limited to the S phase of thecell cycle, but DSBs can trigger cohesion also after DNA replicationhas been completed. The function of this damage-induced cohesionremains unknown. In this investigation, we show that damage-inducedcohesion is essential for repair in postreplicative cells inyeast. Furthermore, it is established genome-wide after inductionof a single DSB, and it is controlled by the DNA damage responseand cohesin-regulating factors. We thus define a cohesion establishmentpathway that is independent of DNA duplication and acts togetherwith cohesion formed during replication in sister chromatidbasedDSB repair.
1 Department of Cell and Molecular Biology, Karolinska Institute, 171 77 Stockholm, Sweden. 2 Gene Research Centre, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, 226-8501 Yokohama, Japan.
* To whom correspondence should be addressed. E-mail: camilla.sjogren{at}ki.se
The tethering of sister chromatids by the cohesin complex, socalled sister-chromatid cohesion, is essential for chromosomesegregation (1). Cohesin consists of Smc1, Smc3, Mcd1 (alsocalled Scc1), and Scc3 and is loaded onto chromosomes beforereplication by Scc2 and Scc4 (2). The establishment of cohesionrequires Eco1 (also called Ctf7) and occurs in the S phase ofthe unchallenged cell cycle (38). Cohesion then persistsuntil anaphase, when it is resolved by proteolytic cleavageof Mcd1, which is triggered by the degradation of Pds1 (911).In addition to its central role in chromosome segregation, replication-establishedcohesion is needed for double-strand break (DSB) repair in postreplicativecells (12). Cohesin also has to be recruited to the site ofdamage for efficient repair (13, 14), and de novo cohesion isestablished in G2/M cells exposed to ionizing irradiation (13).This raises the possibility that chromatid-based DSB repairrequires both cohesion formed during replication and postreplicativedamage-induced cohesion. It also challenges present conceptsthat cohesion establishment is tightly connected to chromosomeduplication. Therefore, we investigated how damage-induced cohesionis regulated and resolved its function in DSB repair and chromosomesegregation.
Central to our investigations are experimental systems in whichdamage-induced cohesion can be distinguished from cohesion formedduring replication (fig. S1, A to C). In one of these systems,smc1-259 temperature-sensitive cells are first arrested in G2/Mat permissive temperature. Thereafter, temperature-resistant,damage-induced cohesion is generated by the expression of wild-type(WT) SMC1 and treatment with -irradiation (Fig. 1, A and B,and fig. S1A) (13). We first ascertained that our results werenot influenced by the absence of a mitotic spindle in nocodazole-arrestedcells (Fig. 1, A and B). Thereafter, we investigated the functionof central DNA damage-response proteins in damage-induced cohesion.Mre11 is one of the first proteins that localizes at a DSB (15)and is essential for the recruitment of cohesin to the damage(14, 16). Accordingly, damage-induced cohesion was compromisedin mre11 cells (Fig. 1C) (17). Other regulators of the DNA damageresponse that influence cohesin's break localization are theTel1 and Mec1 kinases, which phosphorylate histone 2A (H2A)(in humans, H2AX) (14, 18). Phosphorylated H2A (-H2A) marksthe DSB and is required for DSB recruitment of cohesin (14).Correspondingly, the formation of damage-induced cohesion wasdefective in cells lacking Tel1 or Mec1 or in cells expressingnonphosphorylatable H2A (Fig. 1, D to F). However, in the absenceof Tel1 or Mec1, substantial amounts of -H2A and cohesin stillaccumulate at a DSB because of the overlapping function of theother kinase (14, 18). This indicates that Tel1 and/or Mec1could influence cohesion in a way other than through -H2Adependentrecruitment of cohesin. The two kinases also activate Rad9,which in turn transmits the signal to downstream events in theDNA damage response (1921). Damage-induced cohesion was,however, unaffected in rad9 cells (Fig. 1G), showing that ifMec1 and/or Tel1 affect damage-induced cohesion independentlyof cohesin recruitment, this pathway does not include the activationof Rad9.
Fig. 1.. Mre11, Mec1, Tel1, and H2A, but not Rad9 and Rad52, are required for -rayinduced cohesion. (A to H) Chromatid separation at URA3 on chr. V in G2/M-arrested cells after -irradiation and destruction of S phaseestablished cohesion, as described in fig. S1A. (A) Chromatid separation in Cdc20-depleted G2/M-arrested smc1-259, GAL:SMC1-13MYC, MET:CDC20 cells (CB496). (B to H) Chromatid separation in nocodazole G2/M-arrested (B) smc1-259, GAL:SMC1-13MYC cells (CB469), combined with (C) mre11 (CB478), (D) mec1 (CB784), (E) tel1 (CB693), (F) hta1-S129stop, hta2-129stop (CB742), (G) rad9 (CB696), or (H) rad52 (CB571). Gal, galactose addition; IR, irradiation.
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To determine whether replication induced by the repair processinfluences cohesion, we investigated damage-induced cohesionin rad52 cells. Rad52 facilitates the direct interaction betweenthe DNA flanking a DSB and an undamaged homologous template,which is essential for eliciting DNA synthesis at the break(22, 23). Therefore, the unperturbed formation of cohesion inrad52D cells (Fig. 1F) shows that, in contrast to the establishmentprocess in unchallenged cells, damage-induced cohesion is independentof ongoing DNA duplication (17).
We observed chromatid separation in a limited region of chromosomeV (chr. V) that experiences roughly one DSB per cell at theirradiation dose applied (13). Because cohesin is recruitedto only 50 to 100 kb around the DSB (13, 14), the -rayinducedcohesion suggests a more general activation of cohesin (Fig. 1, A and B).To investigate whether a single genomic DSB triggers cohesion,we used an uncleavable variant of Mcd1 (Mcd1UNCL) that blockschromatid separation at anaphase when it is present in cohesion-formingcomplexes (10, 24) (fig. S1C). When Mcd1UNCL was expressed alonein G2/M-arrested cells, chr. V separated normally during a releasefrom the arrest. In contrast, chr. V separation did not occurwhen Mcd1UNCL expression was combined with the induction ofa homothallic switching (HO)endonuclease that createsa DSB at the MAT locus on chr. III (Fig. 2, A to C). This inhibitionwas not due to a cell-cycle delay caused by the break, becausePds1 levels declined concomitantly in both cell populations(Fig. 2B), and HO expression alone left chromatid separationunperturbed (Fig. 2, D and E). Moreover, HO overexpression didnot generate DSBs at unspecific sites in the genome, becausethe chromatids separated normally after the induction of HOand Mcd1UNCL in MATD cells (Fig. 2, D and E). As a control ofMcd1UNCL function, its chromosomal localization after expressionin G2/M was determined and shown to be identical to normallyexpressed Mcd1 (fig. S2) (8). This finding establishes thata break on chr. III triggers the formation of cohesion on chr.V, demonstrating that a single DSB reactivates cohesion in agenome-wide manner.
Fig. 2.. A single DSB on chr. III leads to establishment of cohesion on chr. V. MCD1UNCL was induced in G/M-arrested cells, with or without a concomitant DSB on chr. III. Cells were thereafter released into the next cell cycle under non-inducing conditions (fig. S1C). Chromatid separation at URA3 on chr. V, thepercentageof Pds1-positive cells, and chr. III breakage were determined. (A) Sister-chromatid separation in GAL:MCD1UNCL, PDS1-18MYCcells without (CB699) or with GAL:HO (CB507). (B) Pds1-positive cells in (A). (C) Southern blot of chr. III isolated from cells examined in (A). (D) Sister-chromatid separation in GAL:MCD1 (CB699), GAL:MCD1 GAL:HO (CB507), GAL:HO (CB524), or MCD1UNCL GAL:HO mat (CB586). (E) Analysis of chr. III in cells examined in (D).
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We next investigated how genome-wide cohesion is regulated usingG2/M-arrested temperature-sensitive smc1-259 cells in whichWT SMC1 and a DSB on chr. III was induced before an up-shiftin temperature (fig. S1B). This experiment showed that "global"cohesion depends on Mec1 and partly on Tel1 and -H2A, but noton Rad9 (Fig. 3, A and B, and fig. S3A). In cells lacking -H2A,nocohesinis recruited to damaged chromosomes, but cohesion isonly partly defective when compared with mec1 cells (14). Thisobservation indicates that Mec1 is required for more than cohesinlocalization and could be a key factor in the transmission ofa signal from damaged to undamaged chromosomes. If so, thistransmission is achieved in a Rad9-independent manner. The partialrequirement for Tel1 and -H2A in global cohesion could be dueto a function in amplifying the signal emanating from the DSB(25). Such a function of -H2A is supported by our finding thatit covers the entire chr. III after the prolonged break inductionthat we used in our experiments, but is absent on undamagedchromosomes (fig. S3B).
Fig. 3.. Genome-wide cohesion depends both on the DNA damage response and on proteins regulating cohesin function. (A and B) Chr. V chromatid separation in G2/M-arrested cells after removal of S phaseestablished cohesion, in the absence or presence of a DSB on chr. III, as described in fig. S1B. (A) Chromatid separation in smc1-259, GAL:HO (CB583), and smc1-259 GAL:SMC1-13MYC GAL:HO (CB479). (B) Chromatid separation in smc1-259, GAL: SMC1-13MYC, GAL:HO cells (CB479), combined with tel1 (CB815), mec1 (CB753), hta1-S129stop, hta2-129stop (CB740), or rad9 (CB813). DSB formation on chr. III is shown in fig. S3A (C to E) Chromatid separation of chr. V in cells containing GAL:MCD1UNCL and GAL:HO. The experiments were performed as in Fig. 2 and fig. S1C, with the exception that the temperature was up-shifted 30 min after the addition of galactose. (C) Wild type (CB507) and scc2-4 (CB573), (D) wild type and smc6-56 (CB537), and (E) wild type and eco1-1 (CB732). (F) Chip-on-chip analysis of Scc2 localizationon chr. III in the absence (DSB) or presence (+DSB) of a DSB at the MAT locus. Arrow indicates a DSB. CENIII, chr. III centromere.
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We also explored the role of cohesin-regulating proteins ingenome-wide cohesion by scoring chr. V separation after theinduction of Mcd1UNCL and a DSB on chr. III in temperature-sensitivescc2-4, smc6-56, or eco1-1 cells. These experiments showed thatScc2, Smc6, and Eco1 are required for global cohesion (Fig. 3, C to E,and fig. S3C).
The prerequisite of Scc2 reveals that genome-wide formationof cohesion requires the loading of cohesin to chromosomes.Loading in G2/M occurs also in the absence of DNA damage, andthe cohesins present on chromosomes in this cell-cycle phaseare thus a mixture of cohesive and noncohesive complexes (8).Our findings indicate that a DSB triggers an alteration of cohesinor its effectors that activate the cohesive function of thenormally unproductive complexes. We investigated whether thisis reflected by a change in the localization of Scc2 on undamagedchromosomes, but found that HO expression only induced its accumulationat the DSB (Fig. 3F). This is true also for cohesin (13), showingthat genome-wide cohesion is generated without positional changesof cohesin or its loader in undamaged regions of the genome.
The Smc6 protein is part of the cohesinrelated Smc5/6 complex,which also is required for sister-chromatid repair, and regulatesthe localization of cohesin to DNA breaks in human cells (26,27). In yeast, however, the chromosomal association of Mcd1was unaltered after the destruction of smc6-56 function in G2/M-arrestedcells (fig. S3D). This suggests that the requirement of Smc6for genome-wide cohesion reflects a more direct influence oncohesin function, which is in accordance with the similar chromosomallocalization patterns of cohesin and the Smc5/6 complex (28).
The finding that Eco1 is required for genome-wide cohesion showsthat it can act independently of chromosome replication. Italso indicates that the damage response removes an inhibitorymechanism and/or reactivates Eco1, thereby allowing cohesionformation in postreplicative cells. Because the eco1-1 mutationleaves the chromosomal association of cohesin unaffected (fig.S4) (4), we examined whether the establishment of damage-inducedcohesion and not only chromosomal loading of cohesin is neededfor repair (12, 29). The results showed that Eco1, and consequentlydamage-induced cohesion, is required for postreplicative DSBrepair (Fig. 4, A and B). In contrast, the absence of damage-inducedcohesion did not interfere with segregation in the presenceof functional replication-established cohesion (Fig. 4C). Thus,a possible explanation for genome-wide cohesion is that postreplicativerepair requires cohesion at a DSB, and this is achieved by aglobal activation of the cohesion machinery, leading to de novocohesion on all chromosomes.
Fig. 4.. Postreplicative function of Eco1 is required for DSB repair but dispensable for chromosome segregation. (A and B) DNA repair and sister-chromatid separation at URA3 in G2/M-arrested WT (CB167) and eco1-1 (CB720) cells. After arrest in G2/M at 21°C, half of the cultures were transferred to 32°C for 30 min, and then all cells were treated with 200 grays of -irradiation (IR) (1 gray = 100 rads). At indicated time points and temperatures, samples were withdrawn for analyses of DNA repair by pulsed-field gel electrophoresis (PFGE) and sister-chromatid separation (29). (Left) Southern blots of the PFGE gel with the use of a radioactive probe detecting chr. XVI and a loading control. (Middle) Quantification of chr. XVI signals normalized to the control. (Right) Chromatid separation. (C) Chromosome segregation in the absence () and presence (+) of genome-wide damage-induced cohesion. G2/M-arrested WT (CB524) or temperature-sensitive eco1-1 (CB755) cells were treated such that damage-induced cohesion was inhibited in eco1-1 cells (29). A DSB on chr. III was induced in half of the cultures. After release into a G1 arrest, the percentage of cells with a single chr. V, reflecting correct chromosome segregation, was determined.
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Our investigation characterizes an additional pathway for cohesionestablishment that is crucial for DSB repair in postreplicativecells. This pathway generates cohesion on undamaged chromosomesin response to a single DSB, suggesting that the break triggersa diffusible signaling event that activates cohesin and/or Eco1via Mec1. Consequently, the establishment of cohesion is notlimited to active replication forks and has to occur both beforeand after DSB formation to repair broken sister chromatids.
Supporting material is available on Science Online.
We thank K. Nasmyth, F. Uhlmann, N. Lowndes, M. Grenon, and J. Downs for providing yeast strains; A. Verreault for H2a antibodies; C. Höög for support; and D. Koshland for communicating unpublished results. For financial support, please see the supporting online material.
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N. Wu, X. Kong, Z. Ji, W. Zeng, P. R. Potts, K. Yokomori, and H. Yu (2012)
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26, 1473-1485
|Abstract »|Full Text »|PDF »
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S. Ghosh, J. M. Gardner, C. J. Smoyer, J. M. Friederichs, J. R. Unruh, B. D. Slaughter, R. Alexander, R. D. Chisholm, K. K. Lee, J. L. Workman, et al. (2012)
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23, 2546-2559
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|Abstract »|Full Text »|PDF »
Calpain-1 Cleaves Rad21 To Promote Sister Chromatid Separation.
A. K. Panigrahi, N. Zhang, Q. Mao, and D. Pati (2011)
Mol. Cell. Biol.
31, 4335-4347
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J.-H. Oum, C. Seong, Y. Kwon, J.-H. Ji, A. Sid, S. Ramakrishnan, G. Ira, A. Malkova, P. Sung, S. E. Lee, et al. (2011)
Mol. Cell. Biol.
31, 3924-3937
|Abstract »|Full Text »|PDF »
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A. Feytout, S. Vaur, S. Genier, S. Vazquez, and J.-P. Javerzat (2011)
Mol. Cell. Biol.
31, 1771-1786
|Abstract »|Full Text »|PDF »
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A. Kegel and C. Sjogren (2011)
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|Abstract »|PDF »
Roles of Vertebrate Smc5 in Sister Chromatid Cohesion and Homologous Recombinational Repair.
A. K. Stephan, M. Kliszczak, H. Dodson, C. Cooley, and C. G. Morrison (2011)
Mol. Cell. Biol.
31, 1369-1381
|Abstract »|Full Text »|PDF »
The splicing-factor related protein SFPQ/PSF interacts with RAD51D and is necessary for homology-directed repair and sister chromatid cohesion.
C. Rajesh, D. K. Baker, A. J. Pierce, and D. L. Pittman (2011)
Nucleic Acids Res.
39, 132-145
|Abstract »|Full Text »|PDF »
Rec8-containing cohesin maintains bivalents without turnover during the growing phase of mouse oocytes.
K. Tachibana-Konwalski, J. Godwin, L. van der Weyden, L. Champion, N. R. Kudo, D. J. Adams, and K. Nasmyth (2010)
Genes & Dev.
24, 2505-2516
|Abstract »|Full Text »|PDF »
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B.-J. Kim, Y. Li, J. Zhang, Y. Xi, Y. Li, T. Yang, S. Y. Jung, X. Pan, R. Chen, W. Li, et al. (2010)
J. Biol. Chem.
285, 22784-22792
|Abstract »|Full Text »|PDF »
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A. R. Leman, C. Noguchi, C. Y. Lee, and E. Noguchi (2010)
J. Cell Sci.
123, 660-670
|Abstract »|Full Text »|PDF »
Yeast cohesin complex embraces 2 micron plasmid sisters in a tri-linked catenane complex.
S. K. Ghosh, C.-C. Huang, S. Hajra, and M. Jayaram (2010)
Nucleic Acids Res.
38, 570-584
|Abstract »|Full Text »|PDF »
Cohesin promotes the repair of ionizing radiation-induced DNA double-strand breaks in replicated chromatin.
C. Bauerschmidt, C. Arrichiello, S. Burdak-Rothkamm, M. Woodcock, M. A. Hill, D. L. Stevens, and K. Rothkamm (2010)
Nucleic Acids Res.
38, 477-487
|Abstract »|Full Text »|PDF »
Increased sister chromatid cohesion and DNA damage response factor localization at an enzyme-induced DNA double-strand break in vertebrate cells.
The Scc2/Scc4 cohesin loader determines the distribution of cohesin on budding yeast chromosomes.
I. Kogut, J. Wang, V. Guacci, R. K. Mistry, and P. C. Megee (2009)
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23, 2345-2357
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21, 2688-2699
|Abstract »|Full Text »|PDF »
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E. A. Outwin, A. Irmisch, J. M. Murray, and M. J. O'Connell (2009)
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29, 4363-4375
|Abstract »|Full Text »|PDF »
The Dot1 Histone Methyltransferase and the Rad9 Checkpoint Adaptor Contribute to Cohesin-Dependent Double-Strand Break Repair by Sister Chromatid Recombination in Saccharomyces cerevisiae.
F. Conde, E. Refolio, V. Cordon-Preciado, F. Cortes-Ledesma, L. Aragon, A. Aguilera, and P. A. San-Segundo (2009)
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182, 437-446
|Abstract »|Full Text »|PDF »
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E. Revenkova, M. L. Focarelli, L. Susani, M. Paulis, M. T. Bassi, L. Mannini, A. Frattini, D. Delia, I. Krantz, P. Vezzoni, et al. (2009)
Hum. Mol. Genet.
18, 418-427
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A. S. Wilkins and R. Holliday (2009)
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181, 3-12
|Full Text »|PDF »
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J.-M. Peters, A. Tedeschi, and J. Schmitz (2008)
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22, 3089-3114
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321, 563-566
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E. Unal, J. M. Heidinger-Pauli, W. Kim, V. Guacci, I. Onn, S. P. Gygi, and D. E. Koshland (2008)
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321, 566-569
|Abstract »|Full Text »|PDF »
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M. Gordillo, H. Vega, A. H. Trainer, F. Hou, N. Sakai, R. Luque, H. Kayserili, S. Basaran, F. Skovby, R. C. M. Hennekam, et al. (2008)
Hum. Mol. Genet.
17, 2172-2180
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L. A. Diaz-Martinez, J. F. Gimenez-Abian, and D. J. Clarke (2008)
J. Cell Sci.
121, 2107-2114
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