The yeast Sgs1 helicase is differentially required for genomic and ribosomal DNA replication

TY - JOUR

T1 - The yeast Sgs1 helicase is differentially required for genomic and ribosomal DNA replication

AU - Versini, Gwennaelle

AU - Comet, Itys

AU - Wu, Michelle

AU - Hoopes, Laura

AU - Schwob, Etienne

AU - Pasero, Philippe

N1 - Keywords: Bromodeoxyuridine; Cell Cycle; Cell Cycle Proteins; DNA Helicases; DNA Replication; DNA, Ribosomal; DNA-Binding Proteins; Humans; Protein-Serine-Threonine Kinases; Rad52 DNA Repair and Recombination Protein; RecQ Helicases; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins

PY - 2003

Y1 - 2003

N2 - The members of the RecQ family of DNA helicases play conserved roles in the preservation of genome integrity. RecQ helicases are implicated in Bloom and Werner syndromes, which are associated with genomic instability and predisposition to cancers. The human BLM and WRN helicases are required for normal S phase progression. In contrast, Saccharomyces cerevisiae cells deleted for SGS1 grow with wild-type kinetics. To investigate the role of Sgs1p in DNA replication, we have monitored S phase progression in sgs1Delta cells. Unexpectedly, we find that these cells progress faster through S phase than their wild-type counterparts. Using bromodeoxyuridine incorporation and DNA combing, we show that replication forks are moving more rapidly in the absence of the Sgs1 helicase. However, completion of DNA replication is strongly retarded at the rDNA array of sgs1Delta cells, presumably because of their inability to prevent recombination at stalled forks, which are very abundant at this locus. These data suggest that Sgs1p is not required for processive DNA synthesis but prevents genomic instability by coordinating replication and recombination events during S phase.

AB - The members of the RecQ family of DNA helicases play conserved roles in the preservation of genome integrity. RecQ helicases are implicated in Bloom and Werner syndromes, which are associated with genomic instability and predisposition to cancers. The human BLM and WRN helicases are required for normal S phase progression. In contrast, Saccharomyces cerevisiae cells deleted for SGS1 grow with wild-type kinetics. To investigate the role of Sgs1p in DNA replication, we have monitored S phase progression in sgs1Delta cells. Unexpectedly, we find that these cells progress faster through S phase than their wild-type counterparts. Using bromodeoxyuridine incorporation and DNA combing, we show that replication forks are moving more rapidly in the absence of the Sgs1 helicase. However, completion of DNA replication is strongly retarded at the rDNA array of sgs1Delta cells, presumably because of their inability to prevent recombination at stalled forks, which are very abundant at this locus. These data suggest that Sgs1p is not required for processive DNA synthesis but prevents genomic instability by coordinating replication and recombination events during S phase.

U2 - 10.1093/emboj/cdg180

DO - 10.1093/emboj/cdg180

M3 - Journal article

C2 - 12682026

SN - 0261-4189

VL - 22

SP - 1939

EP - 1949

JO - EMBO Journal

JF - EMBO Journal

IS - 8

ER -