title: The Saccharomyces cerevisiae Sae2 protein negatively regulates DNA damage checkpoint signalling.
abstract: Double-strand breaks (DSBs) elicit a DNA damage response, resulting in checkpoint-mediated cell-cycle delay and DNA repair. The Saccharomyces cerevisiae Sae2 protein is known to act together with the MRX complex in meiotic DSB processing, as well as in DNA damage response during the mitotic cell cycle. Here, we report that cells lacking Sae2 fail to turn off both Mec1- and Tel1-dependent checkpoints activated by a single irreparable DSB, and delay Mre11 foci disassembly at DNA breaks, indicating that Sae2 may negatively regulate checkpoint signalling by modulating MRX association at damaged DNA. Consistently, high levels of Sae2 prevent checkpoint activation and impair MRX foci formation in response to unrepaired DSBs. Mec1- and Tel1-dependent Sae2 phosphorylation is necessary for these Sae2 functions, suggesting that the two kinases, once activated, may regulate checkpoint switch off through Sae2-mediated inhibition of MRX signalling.
authors.affiliation: Dipartimento di Biotecnologie e Bioscienze, Università di Milano-Bicocca, P.zza della Scienza 2, 20126 Milan, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Clerici
authors.forename: Davide
authors.initials: D
authors.lastname: Mantiero
authors.forename: Giovanna
authors.initials: G
authors.lastname: Lucchini
authors.forename: Maria Pia
authors.initials: MP
authors.lastname: Longhese
mesh_terms: D015153:Blotting, Western; D002453:Cell Cycle; D004249:DNA Damage; D004260:DNA Repair; D004271:DNA, Fungal / Q000235:genetics; D004706:Endodeoxyribonucleases / Q000235:genetics / Q000378:metabolism; D004720:Endonucleases; D005090:Exodeoxyribonucleases / Q000235:genetics / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D005800:Genes, Fungal; D047908:Intracellular Signaling Peptides and Proteins; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D013997:Time Factors
chemical_list: D004271:DNA, Fungal; D005656:Fungal Proteins; D047908:Intracellular Signaling Peptides and Proteins; C107849:SAE2 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C088937:MEC1 protein, S cerevisiae; D017346:Protein Serine-Threonine Kinases; C513623:TEL1 protein, S cerevisiae; D004706:Endodeoxyribonucleases; D004720:Endonucleases; D005090:Exodeoxyribonucleases; C094191:MRE11 protein, S cerevisiae