Role of a complex containing Rad17, Mec3, and Ddc1 in the yeast DNA damage checkpoint pathway.
Genetic analysis has suggested that RAD17, RAD24, MEC3, and DDC1 play similar roles in the DNA damage checkpoint control in budding yeast. These genes are required for DNA damage-induced Rad53 phosphorylation and considered to function upstream of RAD53 in the DNA damage checkpoint pathway. Here we identify Mec3 as a protein that associates with Rad17 in a two-hybrid screen and demonstrate that Rad17 and Mec3 interact physically in vivo. The amino terminus of Rad17 is required for its interaction with Mec3, and the protein encoded by the rad17-1 allele, containing a missense mutation at the amino terminus, is defective for its interaction with Mec3 in vivo. Ddc1 interacts physically and cosediments with both Rad17 and Mec3, indicating that these three proteins form a complex. On the other hand, Rad24 is not found to associate with Rad17, Mec3, and Ddc1. DDC1 overexpression can partially suppress the phenotypes of the rad24Delta mutation: sensitivity to DNA damage, defect in the DNA damage checkpoint and decrease in DNA damage-induced phosphorylation of Rad53. Taken together, our results suggest that Rad17, Mec3, and Ddc1 form a complex which functions downstream of Rad24 in the DNA damage checkpoint pathway.
Kondo
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T
Division of Biological Science, Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya 464-0814, Japan.
Matsumoto
K
K
Sugimoto
K
K
D000483:Alleles; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D018797:Cell Cycle Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D064447:Checkpoint Kinase 2; D004249:DNA Damage; D017931:DNA Primers / Q000235:genetics; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D005800:Genes, Fungal; D047908:Intracellular Signaling Peptides and Proteins; D046911:Macromolecular Substances; D008954:Models, Biological; D009154:Mutation; D009687:Nuclear Proteins; D010766:Phosphorylation; D011485:Protein Binding; D011494:Protein Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins
D018797:Cell Cycle Proteins; D017931:DNA Primers; D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D047908:Intracellular Signaling Peptides and Proteins; C099938:MEC3 protein, S cerevisiae; D046911:Macromolecular Substances; D009687:Nuclear Proteins; C501395:RAD17 protein, S cerevisiae; C088385:RAD24 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D011494:Protein Kinases; D064447:Checkpoint Kinase 2; D017346:Protein Serine-Threonine Kinases; C067022:RAD53 protein, S cerevisiae