Isolation and characterization of the fission yeast protein phosphatase gene ppe1+ involved in cell shape control and mitosis.
We isolated a fission yeast putative protein serine/threonine phosphatase gene designated ppe1+ by hybridization. The predicted amino acid sequence is similar to those of the fission yeast ppa2 (53% identity) and dis2 (39%) phosphatases, and highly similar to those of the budding yeast SIT4 (72%), Drosophila PPV (68%) and rabbit PPX (61%) phosphatases. Antibodies against ppe1 protein identified a 37-kd polypeptide in fission yeast. A gene disruption (designated delta ppe1) caused cold-sensitive lethality and short, pear-shaped cells. These phenotypes were fully suppressed by a plasmid carrying ppe1+. Three classes of multicopy suppressor genes for delta ppe1 were identified as follows: 1) ppa1+ and ppa2+ encoding type 2A-like phosphatases, 2) mitotically essential dis3+ similar to the budding yeast SSD1/SRK1, a suppressor for sit4, and 3) pck1+ coding for a protein kinase C-like kinase. Consistently, the budding yeast SIT4 gene was also a multicopy suppressor for delta ppe1. Phosphatase ppe1 may play a role in cell morphogenesis and mitosis by either regulating or being regulated by these multicopy suppressor gene products. Consistent with this hypothesis, double mutants ppe1-ppa2 and ppe1-pck1 are lethal at the permissive temperature.
Department of Biophysics, Faculty of Science, Kyoto University, Japan.
M
M
Shimanuki
N
N
Kinoshita
H
H
Ohkura
T
T
Yoshida
T
T
Toda
M
M
Yanagida
D000595:Amino Acid Sequence; D001483:Base Sequence; D018797:Cell Cycle Proteins; D003080:Cold Temperature; D004271:DNA, Fungal / Q000235:genetics; D015870:Gene Expression; D005800:Genes, Fungal; D005807:Genes, Overlapping; D016153:Genes, Suppressor; D008938:Mitosis / Q000235:genetics; D008969:Molecular Sequence Data; D005810:Multigene Family; D010641:Phenotype; D010749:Phosphoprotein Phosphatases / Q000235:genetics*; D012568:Schizosaccharomyces / Q000166:cytology / Q000201:enzymology* / Q000235:genetics*; D029702:Schizosaccharomyces pombe Proteins
D018797:Cell Cycle Proteins; D004271:DNA, Fungal; D029702:Schizosaccharomyces pombe Proteins; C106081:ppe1 protein, S pombe; D010749:Phosphoprotein Phosphatases