title: Pachytene exit controlled by reversal of Mek1-dependent phosphorylation.
abstract: During yeast meiosis, a checkpoint prevents exit from pachytene in response to defects in meiotic recombination and chromosome synapsis. This pachytene checkpoint requires two meiotic chromosomal proteins, Red1 and Mek1; Mek1 is a kinase that phosphorylates Red1. In mutants that undergo checkpoint-mediated pachytene arrest, Mek1 is active and Red1 remains phosphorylated. Activation of Mek1 requires the initiation of meiotic recombination and certain DNA damage checkpoint proteins. Mek1 kinase activity and checkpoint-induced pachytene arrest are counteracted by protein phosphatase type 1 (Glc7). Glc7 coimmunoprecipitates with Red1, colocalizes with Red1 on chromosomes, and dephosphorylates Red1 in vitro. We speculate that phosphorylated Red1 prevents exit from pachytene and that completion of meiotic recombination triggers Glc7-dependent dephosphorylation of Red1.
authors.affiliation: Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Bailis
authors.forename: G S
authors.initials: GS
authors.lastname: Roeder
mesh_terms: D002875:Chromosomes / Q000378:metabolism*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins; D007202:Indicators and Reagents / Q000378:metabolism; D008164:Luminescent Proteins / Q000235:genetics; D048369:MAP Kinase Kinase 1; D008540:Meiosis / Q000502:physiology; D020929:Mitogen-Activated Protein Kinase Kinases / Q000235:genetics / Q000378:metabolism*; D009154:Mutation / Q000502:physiology; D009687:Nuclear Proteins; D010749:Phosphoprotein Phosphatases / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D011995:Recombination, Genetic / Q000502:physiology; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000201:enzymology* / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D020798:Two-Hybrid System Techniques
chemical_list: D005656:Fungal Proteins; D007202:Indicators and Reagents; D008164:Luminescent Proteins; D009687:Nuclear Proteins; C086673:RED1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C090118:Zip1 protein, S cerevisiae; D049452:Green Fluorescent Proteins; D017346:Protein Serine-Threonine Kinases; D048369:MAP Kinase Kinase 1; D020929:Mitogen-Activated Protein Kinase Kinases; D010749:Phosphoprotein Phosphatases