Abstract
Yeast cells lacking the SGS1 DNA helicase and the MUS81 structure-specific endonuclease display a synthetic lethality that is suppressed by loss of the RAD51 recombinase. This epistatic interaction suggests that the primary function of SGS1 or MUS81, or both genes, is downstream of RAD51. To identify RAD51-independent functions of SGS1 and MUS81, a synthetic-lethal screen was performed on the sgs1 mus81 rad51triple mutant. We found that mutation of RNH202, which encodes a subunit of the hetero-trimeric RNase H2, generates a profound synthetic-sickness in this background. RNase H2 is thought to play a non-essential role in Okazaki fragment maturation. Cells lacking RNH202 showed synthetic growth defects when combined with either mus81 or sgs1 alone. But, whereas the loss of RAD51 had little effect on rnh202 sgs1 double mutants, it strongly inhibited the growth of rnh202 mus81 cells. These data indicate that the primary function of SGS1, but not MUS81, is downstream of RAD51. SGS1 must have some RAD51-independent function, however, since the growth of rnh202 mus81 rad51cells was further compromised by the loss of SGS1. Consistent with these results, we show that rnh202 cells display a sensitivity to DNA-damaging agents that is exacerbated in the absence of RAD51 or MUS81. These data support a model in which defects in lagging-strand replication are repaired by the Mus81 endonuclease or through a pathway dependent on Rad51 and Sgs1.







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Arudchandran A, Cerritelli S, Narimatsu S, Itaya M, Shin DY, Shimada Y, Crouch RJ (2000) The absence of ribonuclease H1 or H2 alters the sensitivity of Saccharomyces cerevisiae to hydroxyurea, caffeine and ethyl methanesulphonate: implications for roles of RNases H in DNA replication and repair. Genes Cells 5:789–802
Bae SH, Bae KH, Kim JA, Seo YS (2001) RPA governs endonuclease switching during processing of Okazaki fragments in eukaryotes. Nature 412:456–461
Bastin-Shanower SA, Fricke WM, Mullen JR, Brill SJ (2003) The mechanism of Mus81-Mms4 cleavage site selection distinguishes it from the homologous endonuclease Rad1-Rad10. Mol Cell Biol 23:3487–3496
Boddy MN, Gaillard PH, McDonald WH, Shanahan P, Yates JR III, Russell P (2001) Mus81-Eme1 are essential components of a Holliday junction resolvase. Cell 107:537–548
Boeke JD, Trueheart J, Natsoulis G, Fink GR (1987) 5-Fluoroorotic acid as a selective agent in yeast molecular genetics. Meth Enzymol 154:164–175
Cerritelli SM, Frolova EG, Feng C, Grinberg A, Love PE, Crouch RJ (2003) Failure to produce mitochondrial DNA results in embryonic lethality in Rnase h1 null mice. Mol Cell 11:807–815
Chakraverty RK, Hickson ID (1999) Defending genome integrity during DNA replication: a proposed role for RecQ family helicases. Bioessays 21:286–294
Chang M, Bellaoui M, Boone C, Brown GW (2002) A genome-wide screen for methyl methanesulfonate-sensitive mutants reveals genes required for S phase progression in the presence of DNA damage. Proc Natl Acad Sci USA 99:16934–16939
Chapados BR, Chai Q, Hosfield DJ, Qiu J, Shen B Tainer JA (2001) Structural biochemistry of a type 2 RNase H: RNA primer recognition and removal during DNA replication. J Mol Biol 307:541–556
Chen JZ, Qiu J, Shen B, Holmquist GP (2000) Mutational spectrum analysis of RNase H(35) deficient Saccharomyces cerevisiae using fluorescence-based directed termination PCR. Nucleic Acids Res 28:3649–3656
Ciccia A, Constantinou A, West SC (2003) Identification and characterization of the human Mus81-Eme1 endonuclease. J Biol Chem 278:25172–25178
Doe CL, Whitby MC (2004) The involvement of Srs2 in post-replication repair and homologous recombination in fission yeast. Nucleic Acids Res 32:1480–1491
Doe CL, Osman F, Dixon J, Whitby MC (2004) DNA repair by a Rad22-Mus81-dependent pathway that is independent of Rhp51. Nucleic Acids Res 32:5570–5581
Ellis NA, Groden J, Ye T-Z, Straughen J, Lennon DJ, Ciocci S, Proytcheva M, German J (1995) The Bloom’s syndrome gene product is homologous to RecQ helicases. Cell 83:655–666
Fabre F, Chan A, Heyer WD, Gangloff S (2002) Alternate pathways involving Sgs1/Top3, Mus81/ Mms4, and Srs2 prevent formation of toxic recombination intermediates from single-stranded gaps created by DNA replication. Proc Natl Acad Sci USA 99:16887–16892
Fan HY, Cheng KK, Klein HL (1996) Mutations in the RNA polymerase II transcription machinery suppress the hyperrecombination mutant hpr1 delta of Saccharomyces cerevisiae. Genetics 142:749–759
Filippov V, Filippov M, Gill SS (2001) Drosophila RNase H1 is essential for development but not for proliferation. Mol Genet Genomics 265:771–777
Formosa T, Nittis T (1999) Dna2 mutants reveal interactions with Dna polymerase alpha and Ctf4, a Pol alpha accessory factor, and show that full Dna2 helicase activity is not essential for growth. Genetics 151:1459–1470
Fu Y, Xiao W (2003) Functional domains required for the Saccharomyces cerevisiae Mus81-Mms4 endonuclease complex formation and nuclear localization. DNA Repair (Amst) 2:1435–1447
Gangloff S, McDonald JP, Bendixen C, Arthur L, Rothstein R (1994) The yeast type I topoisomerase Top3 interacts with Sgs1, a DNA helicase homolog: a potential eukaryotic reverse gyrase. Mol Cell Biol 14:8391–8398
Gangloff S, de Massy B, Arthur L, Rothstein R, Fabre F (1999) The essential role of yeast topoisomerase III in meiosis depends on recombination. EMBO J 18:1701–1711
Gangloff S, Soustelle C, Fabre F (2000) Homologous recombination is responsible for cell death in the absence of the Sgs1 and Srs2 helicases. Nat Genet 25:192–194
Hickson ID (2003) RecQ helicases: caretakers of the genome. Nat Rev Cancer 3:169–178
Hope JC, Maftahi M, Freyer GA (2005) A postsynaptic role for Rhp55/57 that is responsible for cell death in Δrqh1 mutants following replication arrest in Schizosaccharomyces pombe. Genetics 170:519–531
Interthal H, Heyer WD (2000) MUS81 encodes a novel helix-hairpin-helix protein involved in the response to UV- and methylation-induced DNA damage in Saccharomyces cerevisiae. Mol Gen Genet 263:812–827
Ira G, Malkova A, Liberi G, Foiani M, Haber JE (2003) Srs2 and Sgs1-Top3 suppress crossovers during double-strand break repair in yeast. Cell 115:401–411
Itaya M (1990) Isolation and characterization of a second RNase H (RNase HII) of Escherichia coli K-12 encoded by the rnhB gene. Proc Natl Acad Sci USA 87:8587–8591
Jeong HS, Backlund PS, Chen HC, Karavanov AA, Crouch RJ (2004) RNase H2 of Saccharomyces cerevisiae is a complex of three proteins. Nucleic Acids Res 32:407–414
Kaliraman V, Mullen JR, Fricke WM, Bastin-Shanower SA, Brill SJ (2001) Functional overlap between Sgs1-Top3 and the Mms4-Mus81 endonuclease. Genes Dev 15:2730–2740
Kao HI, Bambara RA (2003) The protein components and mechanism of eukaryotic Okazaki fragment maturation. Crit Rev Biochem Mol Biol 38:433–452
Kitao S, Shimamoto A, Goto M, Miller RW, Smithson WA, Lindor NM, Furuichi Y (1999) Mutations in RECQL4 cause a subset of cases of Rothmund-Thomson syndrome. Nat Genet 22:82–84
Laursen LV, Ampatzidou E, Andersen AH, Murray JM (2003) Role for the fission yeast RecQ helicase in DNA repair in G2. Mol Cell Biol 23:3692–3705
Maftahi M, Hope JC, Delgado-Cruzata L, Han CS, Freyer GA (2002) The severe slow growth of Δsrs2 Δrqh1 in Schizosaccharomyces pombe is suppressed by loss of recombination and checkpoint genes. Nucleic Acids Res 30:4781–4792
Mullen JR, Kaliraman V, Brill SJ (2000) Bipartite structure of the SGS1 DNA helicase in Saccharomyces cerevisiae. Genetics 154:1101–1114
Mullen JR, Kaliraman V, Ibrahim SS, Brill SJ (2001) Requirement for three novel protein complexes in the absence of the Sgs1 DNA helicase in Saccharomyces cerevisiae. Genetics 157:103–118
Murray JM, Lindsay HD, Munday CA, Carr AM (1997) Role of Schizosaccharomyces pombe RecQ homolog, recombination, and checkpoint genes in UV damage tolerance. Mol Cell Biol 17:6868–6875
Myung K, Datta A, Chen C, Kolodner RD (2001) SGS1, the Saccharomyces cerevisiae homologue of BLM and WRN, suppresses genome instability and homeologous recombination. Nat Genet 27:113–116
Nitiss J, Wang JC (1988) DNA topoisomerase-targeting antitumor drugs can be studied in yeast. Proc Natl Acad Sci USA 85:7501–7505
Oakley TJ, Goodwin A, Chakraverty RK, Hickson ID (2002) Inactivation of homologous recombination suppresses defects in topoisomerase III-deficient mutants. DNA Repair (Amst) 1:463–482
Odagiri N, Seki M, Onoda F, Yoshimura A, Watanabe S, Enomoto T (2003) Budding yeast mms4 is epistatic with rad52 and the function of Mms4 can be replaced by a bacterial Holliday junction resolvase. DNA Repair (Amst) 2:347–358
Ogrunc M, Sancar A (2003) Identification and characterization of human MUS81-MMS4 structure-specific endonuclease. J Biol Chem 278:21715–21720
Ohtani N, Haruki M, Morikawa M, Crouch RJ, Itaya M, Kanaya S (1999) Identification of the genes encoding Mn2+-dependent RNase HII and Mg2+-dependent RNase HIII from Bacillus subtilis: classification of RNases H into three families. Biochemistry 38:605–618
Onoda F, Seki M, Miyajima A, Enomoto T (2001) Involvement of SGS1 in DNA damage-induced heteroallelic recombination that requires RAD52 in Saccharomyces cerevisiae. Mol Gen Genet 264:702–708
Ooi SL, Shoemaker DD, Boeke JD (2003) DNA helicase gene interaction network defined using synthetic lethality analyzed by microarray. Nat Genet 35:277–286
Paques F, Haber JE (1999) Multiple pathways of recombination induced by double-strand breaks in Saccharomyces cerevisiae. Microbiol Mol Biol Rev 63:349–404
Qiu J, Qian Y, Frank P, Wintersberger U, Shen B (1999) Saccharomyces cerevisiae RNase H(35) functions in RNA primer removal during lagging-strand DNA synthesis, most efficiently in cooperation with Rad27 nuclease. Mol Cell Biol 19:8361–8371
Rattray AJ, Symington LS (1994) Use of a chromosomal inverted repeat to demonstrate that the RAD51 and RAD52 genes of Saccharomyces cerevisiae have different roles in mitotic recombination. Genetics 138:587–595
Ray DS, Hines JC (1995) Disruption of the Crithidia fasciculata RNH1 gene results in the loss of two active forms of ribonuclease H. Nucleic Acids Res 23:2526–2530
Rong L, Palladino F, Aguilera A, Klein HL (1991) The hyper-gene conversion hpr5–1 mutation of Saccharomyces cerevisiae is an allele of the SRS2/RADH gene. Genetics 127:75–85
Rose MD, Winston F, Hieter P (1990) Methods in yeast genetics. Cold Spring Harbor Laboratory Press, Cold Spring Harbor
Rydberg B, Game J (2002) Excision of misincorporated ribonucleotides in DNA by RNase H (type 2) and FEN-1 in cell-free extracts. Proc Natl Acad Sci USA 99:16654–16659
Schramke V, Luciano P, Brevet V, Guillot S, Corda Y, Longhese MP, Gilson E, Geli V (2004) RPA regulates telomerase action by providing Est1p access to chromosome ends. Nat Genet 36:46–54
Shor E, Gangloff S, Wagner M, Weinstein J, Price G, Rothstein R (2002) Mutations in homologous recombination genes rescue top3 slow growth in Saccharomyces cerevisiae. Genetics 162:647–662
Sinclair DA, Mills K, Guarente L (1997) Accelerated aging and nucleolar fragmentation in yeast sgs1 mutants. Science 277:1313–1316
Smogorzewska A, de Lange T (2004) Regulation of telomerase by telomeric proteins. Annu Rev Biochem 73:177–208
Symington LS (1998) Homologous recombination is required for the viability of rad27 mutants. Nucleic Acids Res 26:5589–5595
Thomas BJ, Rothstein R (1989) Elevated recombination rates in transcriptionally active DNA. Cell 56:619–630
Tong AH, Evangelista M, Parsons AB, Xu H, Bader GD, Page N, Robinson, M, Raghibizadeh S, Hogue CW, Bussey H et al. (2001) Systematic genetic analysis with ordered arrays of yeast deletion mutants. Science 294:2364–2368
Ui A, Seki M, Ogiwara H, Onodera R, Fukushige S, Onoda F, Enomoto T (2005) The ability of Sgs1 to interact with DNA topoisomerase III is essential for damage-induced recombination. DNA Repair (Amst) 4:191–201
Vance JR, Wilson TE (2002) Yeast Tdp1 and Rad1-Rad10 function as redundant pathways for repairing Top1 replicative damage. Proc Natl Acad Sci USA 99:13669–13674
Wallis JW, Chrebet G, Brodsky G, Rolfe M, Rothstein R (1989) A hyper-recombination mutation in S. cerevisiae identifies a novel eukaryotic topoisomerase. Cell 58:409–419
Wang X, Ira G, Tercero JA, Holmes AM, Diffley JF, Haber JE (2004) Role of DNA replication proteins in double-strand break-induced recombination in Saccharomyces cerevisiae. Mol Cell Biol 24:6891–6899
Watt PM, Louis EJ, Borts RH, Hickson ID (1995) Sgs1: a eukaryotic homolog of E. coli RecQ that interacts with topoisomerase II in vivo and is required for faithful chromosome segregation. Cell 81:253–260
Watt PM, Hickson ID, Borts RH, Louis EJ (1996) SGS1, a homologue of the Bloom’s and Werner’s syndrome genes, is required for maintenance of genome stability in Saccharomyces cerevisiae. Genetics 144:935–945
Whitby MC, Osman F, Dixon J (2003) Cleavage of model replication forks by fission yeast Mus81-Eme1 and budding yeast Mus81-Mms4. J Biol Chem 278:6928–6935
Wotton D, Shore D (1997) A novel Rap1p-interacting factor, Rif2p, cooperates with Rif1p to regulate telomere length in Saccharomyces cerevisiae. Genes Dev 11:748–760
Wu C, Weiss K, Yang C, Harris MA, Tye BK, Newlon CS, Simpson RT, Haber JE (1998) Mcm1 regulates donor preference controlled by the recombination enhancer in Saccharomyces mating-type switching. Genes Dev 12:1726–1737
Wu L, Davies SL, North PS, Goulaouic H, Riou JF, Turley H, Gatter KC, Hickson ID (2000) The Bloom’s syndrome gene product interacts with topoisomerase III. J Biol Chem 275:9636–9644
Wu L, Davies SL, Levitt NC, Hickson ID (2001) Potential role for the BLM helicase in recombinational repair via a conserved interaction with RAD51. J Biol Chem 276:19375–19381
Yamagata K, Kato J, Shimamoto A, Goto M, Furuichi Y, Ikeda H (1998) Bloom’s and Werner’s syndrome genes suppress hyperrecombination in yeast sgs1 mutant: implication for genomic instability in human diseases. Proc Natl Acad Sci USA 95:8733–8738
Yu CE, Oshima J, Fu YH, Wijsman EM, Hisama F, Alisch R, Matthews S, Nakura J, Miki T, Ouais S et al (1996) Positional cloning of the Werner’s syndrome gene. Science 272:258–262
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We thank Hannah Klein and Lorraine Symington for strains and reagents, and members of lab for encouragement. This work was supported by NIH grant GM067956.
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Ii, M., Brill, S.J. Roles of SGS1, MUS81, and RAD51 in the repair of lagging-strand replication defects in Saccharomyces cerevisiae . Curr Genet 48, 213–225 (2005). https://doi.org/10.1007/s00294-005-0014-5
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DOI: https://doi.org/10.1007/s00294-005-0014-5