title: Suppressor analysis of the mpt5/htr1/uth4/puf5 deletion in Saccharomyces cerevisiae.
abstract: The MPT5/HTR1/UTH4/PUF5 gene encodes an RNA-binding Puf-family protein in Saccharomyces cerevisiae. The Deltampt5 cells exhibit pleiotropic phenotypes, including the G2/M arrest of the cell cycle and weakened cell wall at high temperatures. The Deltampt5 disruptant was also hydroxyurea (HU) sensitive. In this study we screened deletion suppressors to rescue the temperature sensitivity of Deltampt5, and identified dsf1 (YEL070W), dsf2 (YBR007C), sir2, sir3, sir4 and swe1. Multicopy suppressors identified were PKC1 and its upstream genes, but not the downstream MAPK cascade genes. The overexpression of PKC1, however, did not suppress the HU sensitivity of Deltampt5. In contrast, both the HU- and temperature-sensitivities of a-type Deltampt5 cells were suppressed by each sir deletion or a multicopy of MATalpha2, suggesting that a diploid-type expression is involved. We found that a diploid-specific IME4 gene encoding an RNA-modifying protein was responsible for the suppression of the temperature sensitivity, but not of the HU sensitivity. Furthermore, the suppression of the HU sensitivity depended on PUF4, another Puf-family gene, and overexpression of PUF4 suppressed only the HU sensitivity of Deltampt5. The protein level of Puf4 was not affected by the sir mutation. Thus, these Ime4 and Puf4 proteins play complementary roles to rescue the defects in Deltampt5 Deltasir cells.
authors.affiliation: Division of Molecular Mycology and Medicine, Center for Neurological Disease and Cancer, Graduate School of Medicine, Nagoya University, 466-8550 Nagoya, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Ohkuni
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Kikuchi
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Hara
authors.forename: Tsuya
authors.initials: T
authors.lastname: Taneda
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Hayashi
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kikuchi
mesh_terms: D018797:Cell Cycle Proteins / Q000235:genetics*; D002455:Cell Division / Q000235:genetics; D002473:Cell Wall / Q000235:genetics; D004791:Enzyme Inhibitors / Q000494:pharmacology; D016195:G2 Phase / Q000235:genetics; D017353:Gene Deletion; D016153:Genes, Suppressor; D006358:Hot Temperature; D006918:Hydroxyurea / Q000494:pharmacology; D020929:Mitogen-Activated Protein Kinase Kinases / Q000235:genetics; D011493:Protein Kinase C / Q000235:genetics; D011506:Proteins; D016601:RNA-Binding Proteins / Q000235:genetics; D012097:Repressor Proteins / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics*
chemical_list: D018797:Cell Cycle Proteins; D004791:Enzyme Inhibitors; C062928:MATA2 protein, S cerevisiae; C449502:MPT5 protein, S cerevisiae; C070592:PUF4 protein, S cerevisiae; D011506:Proteins; D016601:RNA-Binding Proteins; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; C490702:PKC1 protein, S cerevisiae; D011493:Protein Kinase C; D020929:Mitogen-Activated Protein Kinase Kinases; D006918:Hydroxyurea