title: Phosphorylations of Sds23/Psp1/Moc1 by stress-activated kinase and cAMP-dependent kinase are essential for regulating cell viability in prolonged stationary phase.
abstract: Under nutritional deprivation caused by prolonged culture, actively growing cells prepare to enter stationary phase. We showed here that Sds23/Psp1/Moc1 was phosphorylated by both cAMP-dependent kinase and stress-activated MAP kinase Sty1 upon entry into stationary phase. Overexpression of the phosphorylation-defective mutant Sds23/Psp1/Moc1 induced cell death in prolonged culture and blocked re-entry into the cell division cycle. These phosphorylations are likely to be required for cell survival during stationary phase and for binding of Ufd2, a Schizosaccharomyces pombe homologue of multi-ubiquitin chain assembly factor E4. Deletion of the Ufd2 gene and overexpression of Sds23/Psp1/Moc1 increased cell viability in prolonged stationary phase. These results suggested that Ufd2 induces cell death in prolonged nutrient deprivation, that Sds23/Psp1/Moc1 may be a target protein of the ubiquitin-fusion degradation pathway for regulation of cell viability under this stress condition, and that Sty1 and PKA activity in stationary phase is essential for interaction between Sds23/Psp1/Moc1 and Ufd2.
authors: Department of Nanobiomedical Science and WCU Research Centre, Dankook University, Cheonan, Chungnam, Republic of Korea.
authors: Young-Joo
authors: YJ
authors: Jang
authors: Misun
authors: M
authors: Won
authors: Hyang-Sook
authors: HS
authors: Yoo
mesh_terms: D002453:Cell Cycle / Q000187:drug effects; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D050296:Microbial Viability; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism; D016297:Mutagenesis, Site-Directed; D010766:Phosphorylation; D012568:Schizosaccharomyces / Q000166:cytology* / Q000235:genetics / Q000378:metabolism; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism*; D012694:Serine / Q000378:metabolism; D013312:Stress, Physiological
chemical_list: D018797:Cell Cycle Proteins; D029702:Schizosaccharomyces pombe Proteins; C103137:Sds23 protein, S pombe; D012694:Serine; D017868:Cyclic AMP-Dependent Protein Kinases; D020928:Mitogen-Activated Protein Kinases; C095409:sty1 protein, S pombe
keywords: Schizosaccharomyces; Sds23/Psp1/Moc1; Sty1; stationary phase