Yeast protein phosphatases Ptp2p and Msg5p are involved in G1-S transition, CLN2 transcription, and vacuole morphogenesis.
We previously reported that double disruption of protein phosphatase (PPase) genes PTP2 (phosphotyrosine-specific PPase) and MSG5 (phosphotyrosine and phosphothreonine/serine-PPase) causes Ca(2+) sensitive growth, whereas the single disruptions do not. This finding suggests that Ptp2p and Msg5p are involved in Ca(2+)-induced stress response in a redundant manner. To gain insight into the molecular mechanism causing calcium sensitivity of the ptp2 msg5 double disruptant, we performed fluorescence-activated cell sorting analysis and found a delayed G1 phase. This delayed G1 was consistent with the defect in bud emergence, and reduced CLN2 transcription upon addition of CaCl(2). We also found that Slt2p is hyper-phosphorylated in the Deltaptp2 Deltamsg5 double disruptant and that the vacuole of the Deltaptp2 Deltamsg5 double disruptant is fragmented even in the absence of Ca(2+). These findings suggest that both Ptp2p and Msg5p are involved in the G1 to S transition and vacuole morphogenesis possibly through their regulation of Slt2 pathway.
Hermansyah
Department of Biotechnology, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan.
Sugiyama
Minetaka
M
Kaneko
Yoshinobu
Y
Harashima
Satoshi
S
D002122:Calcium Chloride / Q000378:metabolism; D002453:Cell Cycle; D016213:Cyclins / Q000096:biosynthesis*; D017353:Gene Deletion; D010744:Phosphoric Monoester Hydrolases / Q000235:genetics / Q000378:metabolism*; D017027:Protein Tyrosine Phosphatases / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D014617:Vacuoles / Q000502:physiology*
C082721:CLN2 protein, S cerevisiae; D016213:Cyclins; D029701:Saccharomyces cerevisiae Proteins; D010744:Phosphoric Monoester Hydrolases; C085791:MSG5 protein, S cerevisiae; D017027:Protein Tyrosine Phosphatases; C528257:Ptp2 protein, S cerevisiae; D002122:Calcium Chloride