Checkpoint functions are required for normal S-phase progression in Saccharomyces cerevisiae RCAF- and CAF-I-defective mutants.
The chromatin-assembly factor I (CAF-I) and the replication-coupling assembly factor (RCAF) complexes function in chromatin assembly during DNA replication and repair and play a role in the maintenance of genome stability. Here, we have investigated their role in checkpoints and S-phase progression. FACS analysis of mutants lacking Asf1 or Cac1 as well as various checkpoint proteins indicated that normal rates of S-phase progression in asf1 mutants have a strong requirement for replication checkpoint proteins, whereas normal S-phase progression in cac1 mutants has only a weak requirement for either replication or DNA-damage checkpoint proteins. Furthermore, asf1 mutants had high levels of Ddc2.GFP foci that were further increased in asf1 dun1 double mutants consistent with a requirement for checkpoint proteins in S-phase progression in asf1 mutants, whereas cac1 mutants had much lower levels of Ddc2.GFP foci that were not increased by a dun1 mutation. Our data suggest that RCAF defects lead to unstable replication forks that are then stabilized by replication checkpoint proteins, whereas CAF-I defects likely cause different types of DNA damage.
Kats
Ellen S
ES
Ludwig Institute for Cancer Research, Department of Medicine, University of California at San Diego School of Medicine, 9500 Gilman Drive, La Jolla, CA 92093-0669, USA.
Albuquerque
Claudio P
CP
Zhou
Huilin
H
Kolodner
Richard D
RD
D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D064447:Checkpoint Kinase 2; D056504:Chromatin Assembly Factor-1; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics*; D004249:DNA Damage; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000235:genetics*; D005800:Genes, Fungal; D006918:Hydroxyurea / Q000494:pharmacology; D008741:Methyl Methanesulfonate / Q000494:pharmacology; D008954:Models, Biological; D018832:Molecular Chaperones; D009154:Mutation; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D016196:S Phase / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism
C109731:ASF1 protein, S cerevisiae; D018797:Cell Cycle Proteins; D056504:Chromatin Assembly Factor-1; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D018832:Molecular Chaperones; C533589:RLF2 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D008741:Methyl Methanesulfonate; D064447:Checkpoint Kinase 2; D017346:Protein Serine-Threonine Kinases; C067022:RAD53 protein, S cerevisiae; D006918:Hydroxyurea