title: DNA repair protein Rad55 is a terminal substrate of the DNA damage checkpoints.
abstract: Checkpoints, which are integral to the cellular response to DNA damage, coordinate transient cell cycle arrest and the induced expression of DNA repair genes after genotoxic stress. DNA repair ensures cellular survival and genomic stability, utilizing a multipathway network. Here we report evidence that the two systems, DNA damage checkpoint control and DNA repair, are directly connected by demonstrating that the Rad55 double-strand break repair protein of the recombinational repair pathway is a terminal substrate of DNA damage and replication block checkpoints. Rad55p was specifically phosphorylated in response to DNA damage induced by the alkylating agent methyl methanesulfonate, dependent on an active DNA damage checkpoint. Rad55p modification was also observed after gamma ray and UV radiation. The rapid time course of phosphorylation and the recombination defects identified in checkpoint-deficient cells are consistent with a role of the DNA damage checkpoint in activating recombinational repair. Rad55p phosphorylation possibly affects the balance between different competing DNA repair pathways.
authors.affiliation: Institute of General Microbiology, CH-3012 Bern, Switzerland.
authors.forename: V I
authors.initials: VI
authors.lastname: Bashkirov
authors.forename: J S
authors.initials: JS
authors.lastname: King
authors.forename: E V
authors.initials: EV
authors.lastname: Bashkirova
authors.forename: J
authors.initials: J
authors.lastname: Schmuckli-Maurer
authors.forename: W D
authors.initials: WD
authors.lastname: Heyer
mesh_terms: D004249:DNA Damage / Q000528:radiation effects; D004260:DNA Repair; D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D010766:Phosphorylation; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D014466:Ultraviolet Rays
chemical_list: D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C087191:RAD55 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins