The Saccharomyces cerevisiae Sae2 protein promotes resection and bridging of double strand break ends.
When eukaryotic chromosomes undergo double strand breaks (DSBs), several evolutionarily conserved proteins, among which the MRX complex, are recruited to the break site, leading to checkpoint activation and DNA repair. The function of the Saccharomyces cerevisiae Sae2 protein, which is known to work together with the MRX complex in meiotic DSB processing and in specific mitotic DSB repair events, is only beginning to be elucidated. Here we provide new insights into the role of Sae2 in mitotic DSB repair. We show that repair by single strand annealing of a single DSB, which is generated by the HO endonuclease between direct repeats, is defective both in the absence of Sae2 and in the presence of the hypomorphic rad50s allele altering the Rad50 subunit of MRX. Moreover, SAE2 overexpression partially suppresses the rad50s single strand annealing repair defects, suggesting that the latter might arise from defective MRX-Sae2 interactions. Finally, SAE2 deletion slows down resection of an HO-induced DSB and impairs DSB end bridging. Thus, Sae2 participates in DSB single strand annealing repair by ensuring both resection and intrachromosomal association of the broken ends.
Clerici
Michela
M
Dipartimento di Biotecnologie e Bioscienze, Università di Milano-Bicocca, P.zza della Scienza 2, 20126 Milano, Italy.
Mantiero
Davide
D
Lucchini
Giovanna
G
Longhese
Maria Pia
MP
D000483:Alleles; D015153:Blotting, Western; D002875:Chromosomes / Q000648:ultrastructure; D004249:DNA Damage; D004260:DNA Repair; D004720:Endonucleases; D019143:Evolution, Molecular; D017353:Gene Deletion; D008540:Meiosis; D008938:Mitosis; D008957:Models, Genetic; D009693:Nucleic Acid Hybridization; D010957:Plasmids / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011485:Protein Binding; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism / Q000502:physiology*; D013997:Time Factors
C107849:SAE2 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D004720:Endonucleases