Journal article
Intracellular Glycerol Levels Modulate the Activity of Sln1p, a Saccharomyces cerevisiae Two-component Regulator
The Journal of biological chemistry, Vol.274(1), pp.360-367
01/01/1999
DOI: 10.1074/jbc.274.1.360
PMCID: PMC2909977
PMID: 9867851
Abstract
The HOG mitogen-activated protein kinase pathway mediates the osmotic stress response in
Saccharomyces cerevisiae
, activating genes like
GPD1
(glycerol phosphate dehydrogenase), required for survival under hyperosmotic conditions. Activity of this pathway is regulated by Sln1p, a homolog of the “two-component” histidine kinase family of signal transduction molecules prominent in bacteria. Sln1p also regulates the activity of a Hog1p-independent pathway whose transcriptional output can be monitored using an Mcm1p-dependent
lacZ
reporter gene. The relationship between the two Sln1p branches is unclear, however, the requirement for unphosphorylated pathway intermediates in Hog1p pathway activation and for phosphorylated intermediates in the activation of the Mcm1p reporter suggests that the two Sln1p branches are reciprocally regulated. To further investigate the signals and molecules involved in modulating Sln1p activity, we have screened for new mutations that elevate the activity of the Mcm1p-dependent
lacZ
reporter gene. We find that loss of function mutations in
FPS1
, a gene encoding the major glycerol transporter in yeast activates the reporter in a
SLN1
-dependent fashion. We propose that elevated intracellular glycerol levels in the
fps1
mutant shift Sln1p to the phosphorylated state and trigger the Sln1-dependent activity of the Mcm1 reporter. These observations are consistent with a model in which Sln1p autophosphorylation is triggered by a hypo-osmotic stimulus and indicate that the Sln1p osmosensor is tied generally to osmotic balance, and may not specifically sense an external osmolyte.
Details
- Title: Subtitle
- Intracellular Glycerol Levels Modulate the Activity of Sln1p, a Saccharomyces cerevisiae Two-component Regulator
- Creators
- Wei Tao - Department of Biological Sciences, University of Iowa, Iowa City, Iowa 52242 Department of Biochemistry, University of Iowa, Iowa City, Iowa 52242Robert J Deschenes - Department of Biological Sciences, University of Iowa, Iowa City, Iowa 52242 Department of Biochemistry, University of Iowa, Iowa City, Iowa 52242Jan S Fassler - Department of Biological Sciences, University of Iowa, Iowa City, Iowa 52242 Department of Biochemistry, University of Iowa, Iowa City, Iowa 52242
- Resource Type
- Journal article
- Publication Details
- The Journal of biological chemistry, Vol.274(1), pp.360-367
- DOI
- 10.1074/jbc.274.1.360
- PMID
- 9867851
- PMCID
- PMC2909977
- NLM abbreviation
- J Biol Chem
- ISSN
- 0021-9258
- eISSN
- 1083-351X
- Language
- English
- Date published
- 01/01/1999
- Academic Unit
- Biology
- Record Identifier
- 9984217527302771
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