Isolation and characterization of high-osmolarity-sensitive mutants of fission yeast
For the fission yeast Schizosaccharomyces pombe, adaptation to high-osmolarity medium is mediated by a mitogen-activated protein (MAP) kinase cascade, involving the Wis1 MAP kinase kinase and the Sty1 MAP kinase. The MAP kinase pathway transduces an osmotic signal and accordingly regulates the expre...
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Published in | Journal of Bacteriology Vol. 180; no. 19; pp. 5038 - 5043 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
American Society for Microbiology
01.10.1998
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Subjects | |
Online Access | Get full text |
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Summary: | For the fission yeast Schizosaccharomyces pombe, adaptation to high-osmolarity medium is mediated by a mitogen-activated protein (MAP) kinase cascade, involving the Wis1 MAP kinase kinase and the Sty1 MAP kinase. The MAP kinase pathway transduces an osmotic signal and accordingly regulates the expression of the downstream target gene (gpd1+) that encodes NADH-dependent glycerol-3-phosphate dehydrogenase, in order to adaptively accumulate glycerol inside the cells as an osmoprotectant. We previously characterizd a set of high-osmolarity-sensitive S. pombe mutants, including wis1, sty1, and gpd1. In this study, we attempted to further isolate novel osmolarity-sensitive mutants. For some of the mutants isolated, profiles of glycerol production in response to the osmolarity of the growth medium were indistinguishable from that of the wild-type cells, suggesting that they are novel types. They were classified into three distinct types genetically and, thus, were designated hos1, hos2, and hos3 (high osmolarity sensitive) mutants. One of them, the hos1 mutant, was characterized in detail. The hos1 mutant was demonstrated to have a mutational lesion in the known ryh1+ gene, which encodes a small GTP-binding protein. Disruption of the ryh1+ gene results not only in osmosensitivity but also in temperature sensitivity for growth. It was also found that the delta ryh1 mutant is severely sterile. These results are discussed with special reference to the osmoadaptation of S. pombe |
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Bibliography: | F60 F30 1999004529 ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2 Corresponding author. Mailing address: Laboratory of Molecular Microbiology, School of Agriculture, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan. Phone: 81 52 789 4093. Fax: 81 52 789 4091. E-mail: aiba@nuagr1.agr.nagoya-u.ac.jp. |
ISSN: | 0021-9193 1098-5530 1067-8832 |
DOI: | 10.1128/jb.180.19.5038-5043.1998 |