title: Evidence of meiotic crossover control in Saccharomyces cerevisiae through Mec1-mediated phosphorylation of replication protein A.
abstract: Replication protein A (RPA) is the major single-stranded DNA-binding protein in eukaryotes, essential for DNA replication, repair, and recombination. During mitosis and meiosis in budding yeast, RPA becomes phosphorylated in reactions that require the Mec1 protein kinase, a central checkpoint regulator and homolog of human ATR. Through mass spectrometry and site-directed mutagenesis, we have now identified a single serine residue in the middle subunit of the RPA heterotrimer that is targeted for phosphorylation by Mec1 both in vivo and in vitro. Cells containing a phosphomimetic version of RPA generated by mutation of this serine to aspartate exhibit a significant alteration in the pattern of meiotic crossovers for specific genetic intervals. These results suggest a new function of Mec1 that operates through RPA to locally control reciprocal recombination.
authors.affiliation: Barbara Ann Karmanos Cancer Institute and Department of Pathology, Wayne State University School of Medicine, Detroit, Michigan 48201, USA.
authors.forename: Amy J
authors.initials: AJ
authors.lastname: Bartrand
authors.forename: Dagmawi
authors.initials: D
authors.lastname: Iyasu
authors.forename: Suzanne M
authors.initials: SM
authors.lastname: Marinco
authors.forename: George S
authors.initials: GS
authors.lastname: Brush
mesh_terms: D002384:Catalysis; D047908:Intracellular Signaling Peptides and Proteins; D007700:Kinetics; D013058:Mass Spectrometry; D008540:Meiosis; D008938:Mitosis; D016297:Mutagenesis, Site-Directed; D009154:Mutation / Q000235:genetics; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases; D011995:Recombination, Genetic; D051716:Replication Protein A / Q000235:genetics* / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000254:growth & development / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D012694:Serine / Q000737:chemistry / Q000235:genetics
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D051716:Replication Protein A; D029701:Saccharomyces cerevisiae Proteins; D012694:Serine; C088937:MEC1 protein, S cerevisiae; D017346:Protein Serine-Threonine Kinases