title: A novel gene, msa1, inhibits sexual differentiation in Schizosaccharomyces pombe.
abstract: Sexual differentiation in the fission yeast Schizosaccharomyces pombe is triggered by nutrient starvation or by the presence of mating pheromones. We identified a novel gene, msa1, which encodes a 533-aa putative RNA-binding protein that inhibits sexual differentiation. Disruption of the msa1 gene caused cells to hypersporulate. Intracellular levels of msa1 RNA and Msa1 protein diminished after several hours of nitrogen starvation. Genetic analysis suggested that the function of msa1 is independent of the cAMP pathway and stress-responsive pathway. Deletion of the ras1 gene in diploid cells inhibited sporulation and in haploid cells decreased expression of mating-pheromone-induced genes such as mei2, mam2, ste11, and rep1; simultaneous deletion of msa1 reversed both phenotypes. Overexpression of msa1 decreased activated Ras1(Val17)-induced expression of mam2. Phenotypic hypersporulation was similar between cells with deletion of only rad24 and both msa1 and rad24, but simultaneous deletion of msa1 and msa2/nrd1 additively increased hypersporulation. Therefore, we suggest that the primary function of Msa1 is to negatively regulate sexual differentiation by controlling the expression of Ste11-regulated genes, possibly through the pheromone-signaling pathway.
authors.affiliation: Department of Life Science and Biotechnology, Faculty of Life and Environmental Science, Shimane University, Matsue 690-8504, Japan.
authors.forename: Hee Tae
authors.initials: HT
authors.lastname: Jeong
authors.forename: Fumiyo
authors.initials: F
authors.lastname: Ozoe
authors.forename: Katsunori
authors.initials: K
authors.lastname: Tanaka
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Nakagawa
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Matsuda
authors.forename: Makoto
authors.initials: M
authors.lastname: Kawamukai
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D015152:Blotting, Northern; D015153:Blotting, Western; D018797:Cell Cycle Proteins / Q000502:physiology; D000242:Cyclic AMP / Q000378:metabolism; D000939:Epitopes; D017353:Gene Deletion; D015723:Gene Library; D005800:Genes, Fungal; D005838:Genotype; D006238:Haploidy; D047908:Intracellular Signaling Peptides and Proteins; D008540:Meiosis; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009154:Mutation; D009584:Nitrogen / Q000378:metabolism; D010641:Phenotype; D010957:Plasmids / Q000378:metabolism; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000502:physiology*; D012568:Schizosaccharomyces / Q000502:physiology*; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D017386:Sequence Homology, Amino Acid; D012733:Sex Differentiation; D015398:Signal Transduction; D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D018797:Cell Cycle Proteins; D000939:Epitopes; D047908:Intracellular Signaling Peptides and Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D029702:Schizosaccharomyces pombe Proteins; D014157:Transcription Factors; C495116:msa1 protein, S pombe; C501114:rad24 protein, S pombe; C071596:ste11 protein, S pombe; D000242:Cyclic AMP; D009584:Nitrogen