Evidence that the S.cerevisiae Sgs1 protein facilitates recombinational repair of telomeres during senescence

RecQ DNA helicases, including yeast Sgs1p and the human Werner and Bloom syndrome proteins, participate in telomere biology, but the underlying mechanisms are not fully understood. Here, we explore the protein sequences and genetic interactors of Sgs1p that function to slow the senescence of telomerase (tlc1) mutants. We find that the S-phase checkpoint function of Sgs1p is dispensable for preventing rapid senescence, but that Sgs1p sequences required for homologous recombination, including the helicase domain and topoisomerase III interaction domain, are essential. sgs1 and rad52 mutations are epistatic during senescence, indicating that Sgs1p participates in a RAD52-dependent recombinational pathway of telomere maintenance. Several mutations that are synthetically lethal with sgs1 mutation and which individually lead to genome instability, including mus81, srs2, rrm3, slx1 and top1, do not speed the senescence of tlc1 mutants, indicating that the rapid senescence of sgs1 tlc1 mutants is not caused by generic genome instability. However, mutations in SLX5 or SLX8, which encode proteins that function together in a complex that is required for viability in sgs1 mutants, do speed the senescence of tlc1 mutants. These observations further define roles for RecQ helicases and related proteins in telomere maintenance.

[1]  S. Gasser,et al.  Mechanistically distinct roles for Sgs1p in checkpoint activation and replication fork maintenance , 2005, The EMBO journal.

[2]  J. Strathern,et al.  Methods in yeast genetics : a Cold Spring Harbor Laboratory course manual , 2005 .

[3]  R. Verdun,et al.  Defective Telomere Lagging Strand Synthesis in Cells Lacking WRN Helicase Activity , 2004, Science.

[4]  E. Furth,et al.  Telomere Shortening Exposes Functions for the Mouse Werner and Bloom Syndrome Genes , 2004, Molecular and Cellular Biology.

[5]  G. Behbehani,et al.  Association and regulation of the BLM helicase by the telomere proteins TRF1 and TRF2. , 2004, Human molecular genetics.

[6]  R. DePinho,et al.  Essential role of limiting telomeres in the pathogenesis of Werner syndrome , 2004, Nature Genetics.

[7]  S. Kolvraa,et al.  The Werner syndrome helicase and exonuclease cooperate to resolve telomeric D loops in a manner regulated by TRF1 and TRF2. , 2004, Molecular cell.

[8]  I. Herskowitz,et al.  Anatomy and Dynamics of DNA Replication Fork Movement in Yeast Telomeric Regions , 2004, Molecular and Cellular Biology.

[9]  V. Bohr,et al.  Junction of RecQ Helicase Biochemistry and Human Disease* , 2004, Journal of Biological Chemistry.

[10]  Peter Sperisen,et al.  Telomere Length Homeostasis Is Achieved via a Switch between Telomerase- Extendible and -Nonextendible States , 2004, Cell.

[11]  V. Zakian,et al.  Saccharomyces cerevisiae Rrm3p DNA Helicase Promotes Genome Integrity by Preventing Replication Fork Stalling: Viability of rrm3 Cells Requires the Intra-S-Phase Checkpoint and Fork Restart Activities , 2004, Molecular and Cellular Biology.

[12]  R. Kolodner,et al.  Requirement of Rrm3 Helicase for Repair of Spontaneous DNA Lesions in Cells Lacking Srs2 or Sgs1 Helicase , 2004, Molecular and Cellular Biology.

[13]  R. Monnat,et al.  Werner syndrome protein--unwinding function to explain disease. , 2004, Science of aging knowledge environment : SAGE KE.

[14]  L. Symington,et al.  RAD51-Dependent Break-Induced Replication in Yeast , 2004, Molecular and Cellular Biology.

[15]  V. Zakian,et al.  Local chromatin structure at the ribosomal DNA causes replication fork pausing and genome instability in the absence of the S. cerevisiae DNA helicase Rrm3p. , 2004, Genes & development.

[16]  Gary D Bader,et al.  Global Mapping of the Yeast Genetic Interaction Network , 2004, Science.

[17]  D. Orren,et al.  TRF2 recruits the Werner syndrome (WRN) exonuclease for processing of telomeric DNA , 2004, Oncogene.

[18]  J. Keck,et al.  Structure and Function of RecQ DNA Helicases , 2004, Critical reviews in biochemistry and molecular biology.

[19]  Ian D. Hickson,et al.  The Bloom's syndrome helicase suppresses crossing over during homologous recombination , 2003, Nature.

[20]  Lara K. Goudsouzian,et al.  The Saccharomyces cerevisiae helicase Rrm3p facilitates replication past nonhistone protein-DNA complexes. , 2003, Molecular cell.

[21]  T. Weitao,et al.  Evidence that yeast SGS1, DNA2, SRS2, and FOB1 interact to maintain rDNA stability. , 2003, Mutation research.

[22]  Anna Malkova,et al.  Srs2 and Sgs1–Top3 Suppress Crossovers during Double-Strand Break Repair in Yeast , 2003, Cell.

[23]  J. Boeke,et al.  DNA helicase gene interaction network defined using synthetic lethality analyzed by microarray , 2003, Nature Genetics.

[24]  S. Gasser,et al.  RecQ helicases: multiple roles in genome maintenance. , 2003, Trends in cell biology.

[25]  S. Gasser,et al.  DNA polymerase stabilization at stalled replication forks requires Mec1 and the RecQ helicase Sgs1 , 2003, The EMBO journal.

[26]  S. Brill,et al.  Slx1-Slx4 is a second structure-specific endonuclease functionally redundant with Sgs1-Top3. , 2003, Genes & development.

[27]  J. Murnane,et al.  Telomere instability in a human tumor cell line expressing a dominant-negative WRN protein , 2003, Human Genetics.

[28]  V. Zakian,et al.  Telomerase: what are the Est proteins doing? , 2003, Current opinion in cell biology.

[29]  S. Brill,et al.  The Mechanism of Mus81-Mms4 Cleavage Site Selection Distinguishes It from the Homologous Endonuclease Rad1-Rad10 , 2003, Molecular and Cellular Biology.

[30]  F. Fabre,et al.  The Srs2 helicase prevents recombination by disrupting Rad51 nucleoprotein filaments , 2003, Nature.

[31]  Ying Li,et al.  DNA helicase Srs2 disrupts the Rad51 presynaptic filament , 2003, Nature.

[32]  Philippe Pasero,et al.  The yeast Sgs1 helicase is differentially required for genomic and ribosomal DNA replication , 2003, The EMBO journal.

[33]  I. Hickson.  RecQ helicases: caretakers of the genome , 2003, Nature Reviews Cancer.

[34]  C. Greider,et al.  Short telomeres induce a DNA damage response in Saccharomyces cerevisiae. , 2003, Molecular biology of the cell.

[35]  M. Whitby,et al.  Cleavage of Model Replication Forks by Fission Yeast Mus81-Eme1 and Budding Yeast Mus81-Mms4 , 2003, The Journal of Biological Chemistry.

[36]  M. Adams,et al.  Drosophila BLM in Double-Strand Break Repair by Synthesis-Dependent Strand Annealing , 2003, Science.

[37]  F. Fabre,et al.  Alternate pathways involving Sgs1/Top3, Mus81/ Mms4, and Srs2 prevent formation of toxic recombination intermediates from single-stranded gaps created by DNA replication , 2002, Proceedings of the National Academy of Sciences of the United States of America.

[38]  M. Ikura,et al.  The Bloom syndrome helicase BLM interacts with TRF2 in ALT cells and promotes telomeric DNA synthesis. , 2002, Human molecular genetics.

[39]  R. G. Lloyd,et al.  Recombinational repair and restart of damaged replication forks , 2002, Nature Reviews Molecular Cell Biology.

[40]  I. Hickson,et al.  Telomere-binding Protein TRF2 Binds to and Stimulates the Werner and Bloom Syndrome Helicases* , 2002, The Journal of Biological Chemistry.

[41]  S. Gangloff,et al.  Mutations in homologous recombination genes rescue top3 slow growth in Saccharomyces cerevisiae. , 2002, Genetics.

[42]  N. Maizels,et al.  G4 DNA unwinding by BLM and Sgs1p: substrate specificity and substrate-specific inhibition. , 2002, Nucleic acids research.

[43]  S. Brill,et al.  Role of SGS1 and SLX4 in maintaining rDNA structure in Saccharomyces cerevisiae , 2002, Current Genetics.

[44]  J. Haber,et al.  Recovery from checkpoint-mediated arrest after repair of a double-strand break requires Srs2 helicase. , 2002, Molecular cell.

[45]  J. Derisi,et al.  The genome-wide expression response to telomerase deletion in Saccharomyces cerevisiae , 2002, Proceedings of the National Academy of Sciences of the United States of America.

[46]  I. Hickson,et al.  Inactivation of homologous recombination suppresses defects in topoisomerase III-deficient mutants. , 2002, DNA repair.

[47]  Jin-Qiu Zhou,et al.  Saccharomyces Rrm3p, a 5' to 3' DNA helicase that promotes replication fork progression through telomeric and subtelomeric DNA. , 2002, Genes & development.

[48]  A. Smogorzewska,et al.  Senescence Induced by Altered Telomere State, Not Telomere Loss , 2002, Science.

[49]  A. Ui,et al.  Functional and physical interaction between Sgs1 and Top3 and Sgs1-independent function of Top3 in DNA recombination repair. , 2002, Genes & genetic systems.

[50]  Gary D Bader,et al.  Systematic identification of protein complexes in Saccharomyces cerevisiae by mass spectrometry , 2002, Nature.

[51]  Gary D Bader,et al.  Systematic Genetic Analysis with Ordered Arrays of Yeast Deletion Mutants , 2001, Science.

[52]  S. Brill,et al.  Functional overlap between Sgs1-Top3 and the Mms4-Mus81 endonuclease. , 2001, Genes & development.

[53]  J. Griffith,et al.  T‐loop assembly in vitro involves binding of TRF2 near the 3′ telomeric overhang , 2001, The EMBO journal.

[54]  R. Bennett,et al.  Association of yeast DNA topoisomerase III and Sgs1 DNA helicase: Studies of fusion proteins , 2001, Proceedings of the National Academy of Sciences of the United States of America.

[55]  D. Lev,et al.  Clinical manifestations in a cohort of 41 Rothmund-Thomson syndrome patients. , 2001, American journal of medical genetics.

[56]  J. Haber,et al.  Break-induced replication: A review and an example in budding yeast , 2001, Proceedings of the National Academy of Sciences of the United States of America.

[57]  A. Ui,et al.  The N-terminal region of Sgs1, which interacts with Top3, is required for complementation of MMS sensitivity and suppression of hyper-recombination in sgs1 disruptants , 2001, Molecular Genetics and Genomics.

[58]  V. Lundblad,et al.  Defects in mismatch repair promote telomerase-independent proliferation , 2001, Nature.

[59]  M. Mceachern,et al.  Short telomeres in yeast are highly recombinogenic. , 2001, Molecular cell.

[60]  S. Brill,et al.  Mapping the DNA Topoisomerase III Binding Domain of the Sgs1 DNA Helicase* , 2001, The Journal of Biological Chemistry.

[61]  J. Haber,et al.  Genetic Requirements for RAD51- andRAD54-Independent Break-Induced Replication Repair of a Chromosomal Double-Strand Break , 2001, Molecular and Cellular Biology.

[62]  D. Sinclair,et al.  Recombination-mediated lengthening of terminal telomeric repeats requires the Sgs1 DNA helicase , 2001, Proceedings of the National Academy of Sciences of the United States of America.

[63]  Carol W. Greider,et al.  Two Survivor Pathways That Allow Growth in the Absence of Telomerase Are Generated by Distinct Telomere Recombination Events , 2001, Molecular and Cellular Biology.

[64]  M. McVey,et al.  The Saccharomyces cerevisiae WRN homolog Sgs1p participates in telomere maintenance in cells lacking telomerase , 2001, The EMBO journal.

[65]  E. Louis,et al.  SGS1 is required for telomere elongation in the absence of telomerase , 2001, Current Biology.

[66]  J. Roca,et al.  Circular Minichromosomes Become Highly Recombinogenic in Topoisomerase-deficient Yeast Cells* , 2001, The Journal of Biological Chemistry.

[67]  R. Kolodner,et al.  SGS1, the Saccharomyces cerevisiae homologue of BLM and WRN, suppresses genome instability and homeologous recombination , 2001, Nature Genetics.

[68]  S. Brill,et al.  Requirement for three novel protein complexes in the absence of the Sgs1 DNA helicase in Saccharomyces cerevisiae. , 2001, Genetics.

[69]  L. Hurley,et al.  Inhibition of unwinding of G-quadruplex structures by Sgs1 helicase in the presence of N,N'-bis[2-(1-piperidino)ethyl]-3,4,9,10-perylenetetracarboxylic diimide, a G-quadruplex-interactive ligand. , 2000, Biochemistry.

[70]  F. Fabre,et al.  Homologous recombination is responsible for cell death in the absence of the Sgs1 and Srs2 helicases , 2000, Nature Genetics.

[71]  F. Onoda,et al.  Elevation of sister chromatid exchange in Saccharomyces cerevisiae sgs1 disruptants and the relevance of the disruptants as a system to evaluate mutations in Bloom's syndrome gene. , 2000, Mutation research.

[72]  S. Brill,et al.  Bipartite structure of the SGS1 DNA helicase in Saccharomyces cerevisiae. , 2000, Genetics.

[73]  S. Gasser,et al.  The yeast Sgs1p helicase acts upstream of Rad53p in the DNA replication checkpoint and colocalizes with Rad53p in S-phase-specific foci. , 2000, Genes & development.

[74]  S. Teng,et al.  Telomere-Telomere Recombination Is an Efficient Bypass Pathway for Telomere Maintenance in Saccharomyces cerevisiae , 1999, Molecular and Cellular Biology.

[75]  J. Mccusker,et al.  Three new dominant drug resistance cassettes for gene disruption in Saccharomyces cerevisiae , 1999, Yeast.

[76]  J. Wang,et al.  Binding specificity determines polarity of DNA unwinding by the Sgs1 protein of S. cerevisiae. , 1999, Journal of molecular biology.

[77]  J. Haber,et al.  Multiple Pathways of Recombination Induced by Double-Strand Breaks in Saccharomyces cerevisiae , 1999, Microbiology and Molecular Biology Reviews.

[78]  J. Haber,et al.  RAD50 and RAD51 define two pathways that collaborate to maintain telomeres in the absence of telomerase. , 1999, Genetics.

[79]  P. Defossez,et al.  Effects of Mutations in DNA Repair Genes on Formation of Ribosomal DNA Circles and Life Span inSaccharomyces cerevisiae , 1999, Molecular and Cellular Biology.

[80]  Robert W. Miller,et al.  Mutations in RECQL4 cause a subset of cases of Rothmund-Thomson syndrome , 1999, Nature Genetics.

[81]  N. Maizels,et al.  The Saccharomyces cerevisiae Sgs1 helicase efficiently unwinds G-G paired DNAs. , 1999, Nucleic acids research.

[82]  D A Sinclair,et al.  Accelerated aging and nucleolar fragmentation in yeast sgs1 mutants. , 1997, Science.

[83]  H. Biessmann,et al.  Telomere maintenance without telomerase. , 1997, Chromosoma.

[84]  E. Louis,et al.  SGS1, a homologue of the Bloom's and Werner's syndrome genes, is required for maintenance of genome stability in Saccharomyces cerevisiae. , 1996, Genetics.

[85]  R. Sternglanz,et al.  Human homologues of yeast helicase , 1996, Nature.

[86]  N. Ellis,et al.  Molecular genetics of Bloom's syndrome. , 1996, Human molecular genetics.

[87]  J. Haber,et al.  Double-strand break repair in the absence of RAD51 in yeast: a possible role for break-induced DNA replication. , 1996, Proceedings of the National Academy of Sciences of the United States of America.

[88]  G. Schellenberg,et al.  Positional Cloning of the Werner's Syndrome Gene , 1996, Science.

[89]  N. Ellis,et al.  The Bloom's syndrome gene product is homologous to RecQ helicases , 1995, Cell.

[90]  E. Louis,et al.  Sgs1: A eukaryotic homolog of E. coil RecQ that interacts with topoisomerase II in vivo and is required for faithful chromosome segregation , 1995, Cell.

[91]  S Gangloff,et al.  The yeast type I topoisomerase Top3 interacts with Sgs1, a DNA helicase homolog: a potential eukaryotic reverse gyrase , 1994, Molecular and cellular biology.

[92]  D. Gottschling,et al.  TLC1: template RNA component of Saccharomyces cerevisiae telomerase. , 1994, Science.

[93]  Virginia A. Zakian,et al.  Loss of a yeast telomere: Arrest, recovery, and chromosome loss , 1993, Cell.

[94]  E. Blackburn,et al.  An alternative pathway for yeast telomere maintenance rescues est1− senescence , 1993, Cell.

[95]  J. Szostak,et al.  A mutant with a defect in telomere elongation leads to senescence in yeast , 1989, Cell.

[96]  Gerald R. Fink,et al.  Mitotic recombination in the rDNA of S. cerevisiae is suppressed by the combined action of DNA topoisomerases I and II , 1988, Cell.

[97]  C. Epstein,et al.  A Review of its Symptomatology, Natural History, Pathologic Features, Genetics And Relationship to the Natural Aging Process , 1966 .