The 70 kDa subunit of replication protein A is required for the G1/S and intra-S DNA damage checkpoints in budding yeast.
The rfa1-M2 and rfa1-M4 Saccharomyces cerevisiae mutants, which are altered in the 70 kDa subunit of replication protein A (RPA) and sensitive to UV and methyl methane sulfonate (MMS), have been analyzed for possible checkpoint defects. The G1/S and intra-S DNA damage checkpoints are defective in the rfa1-M2 mutant, since rfa1-M2 cells fail to properly delay cell cycle progression in response to UV irradiation in G1 and MMS treatment during S phase. Conversely, the G2/M DNA damage checkpoint and the S/M checkpoint are proficient in rfa1-M2 cells and all the checkpoints tested are functional in the rfa1-M4 mutant. Preventing S phase entry by alpha-factor treatment after UV irradiation in G1 does not change rfa1-M4 cell lethality, while it allows partial recovery of rfa1-M2 cell viability. Therefore, the hypersensitivity to UV and MMS treatments observed in the rfa1-M4 mutant might only be due to impairment of RPA function in DNA repair, while the rfa1-M2 mutation seems to affect both the DNA repair and checkpoint functions of Rpa70.
Longhese
M P
MP
Dipartimento di Genetica e di Biologia dei Microrganismi, Università di Milano, Italy.
Neecke
H
H
Paciotti
V
V
Lucchini
G
G
Plevani
P
P
D002478:Cells, Cultured; D004249:DNA Damage; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000502:physiology; D016193:G1 Phase; D008741:Methyl Methanesulfonate / Q000494:pharmacology; D008970:Molecular Weight; D016297:Mutagenesis, Site-Directed; D009153:Mutagens / Q000494:pharmacology; D015739:Nocodazole / Q000378:metabolism; D051716:Replication Protein A; D016196:S Phase; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics* / Q000528:radiation effects; D013329:Structure-Activity Relationship; D014466:Ultraviolet Rays
D004268:DNA-Binding Proteins; D009153:Mutagens; D051716:Replication Protein A; D008741:Methyl Methanesulfonate; D015739:Nocodazole