title: Genetic requirements and meiotic function of phosphorylation of the yeast axial element protein Red1.
abstract: The synaptonemal complex (SC) is a meiosis-specific tripartite structure that forms between two homologous chromosomes; it consists of a central region and two parallel lateral elements. Lateral elements also are called axial elements prior to synapsis. In Saccharomyces cerevisiae, Red1, Hop1, and Mek1 are structural components of axial/lateral elements. The red1/mek1/hop1 mutants all exhibit reduced levels of interhomolog recombination and produce no viable spores. Red1 is a phosphoprotein. Several earlier reports proposed that phosphorylated Red1 plays important roles in meiosis, including in signaling meiotic DNA damage or in preventing exit from the pachytene chromosomes. We report here that the phosphorylation of Red1 is carried out in CDC28-dependent and CDC28-independent manners. In contrast to previous results, we found Red1 phosphorylation to be independent of meiotic DNA recombination, the Mec1/Tel1 DNA damage checkpoint kinases, and the Mek1 kinase. To functionally validate the phosphorylation of Red1, we mapped the phosphorylation sites on this protein. A red1(14A) mutant showing no detectable Red1 phosphorylation did not exhibit decreased sporulation efficiency, defects in viable spore production, or defects in meiotic DNA damage checkpoints. Thus, our results suggest that the phosphorylation of Red1 is not essential for its functions in meiosis.
authors.affiliation: Institute of Molecular Biology, Academia Sinica, 128 Academia Road, Taipei 115, Taiwan.
authors.forename: Yi-Ju
authors.initials: YJ
authors.lastname: Lai
authors.forename: Feng-Ming
authors.initials: FM
authors.lastname: Lin
authors.forename: Mei-Jen
authors.initials: MJ
authors.lastname: Chuang
authors.forename: Hui-Ju
authors.initials: HJ
authors.lastname: Shen
authors.forename: Ting-Fang
authors.initials: TF
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D017489:CDC28 Protein Kinase, S cerevisiae / Q000378:metabolism; D002874:Chromosome Mapping; D023902:Chromosome Pairing / Q000235:genetics; D004249:DNA Damage; D004706:Endodeoxyribonucleases / Q000235:genetics / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D048369:MAP Kinase Kinase 1 / Q000378:metabolism; D008540:Meiosis / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation; D010766:Phosphorylation / Q000235:genetics; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D013172:Spores, Fungal / Q000235:genetics / Q000378:metabolism; D000099257:Meiotic Recombination Protein SPO11
chemical_list: D017489:CDC28 Protein Kinase, S cerevisiae; D004706:Endodeoxyribonucleases; D047908:Intracellular Signaling Peptides and Proteins; D048369:MAP Kinase Kinase 1; D017346:Protein Serine-Threonine Kinases; D029701:Saccharomyces cerevisiae Proteins; C086673:RED1 protein, S cerevisiae; C088937:MEC1 protein, S cerevisiae; C518938:Spo11 protein, S cerevisiae; D000099257:Meiotic Recombination Protein SPO11