52 research outputs found
The transcriptional response of Saccharomyces cerevisiae to osmotic shock. Hot1p and Msn2p/Msn4p are required for the induction of subsets of high osmolarity glycerol pathway-dependent genes
Stimulation of the yeast high osmolarity glycerol (HOG) pathway: evidence for a signal generated by a change in turgor rather than by water stress
Stimulation of the yeast high osmolarity glycerol (HOG) pathway: evidence for a signal generated by a change in turgor rather than by water stress
The transcriptional response of Saccharomyces cerevisiae to osmotic shock. Hot1p and Msn2p/Msn4p are required for the induction of subsets of high osmolarity glycerol pathway-dependent genes
Glucose-induced cAMP signalling in yeast requires both a G-protein coupled receptor system for extracellular glucose detection and a separable hexose kinase-dependent sensing process
Sul1 and Sul2 sulfate transceptors signal to protein kinase A upon exit of sulfur starvation
Sulfate is an essential nutrient with pronounced regulatory effects on cellular metabolism and proliferation. Little is known, however, about how sulfate is sensed by cells. Sul1 and Sul2 are sulfate transporters in the yeast Saccharomyces cerevisiae, strongly induced upon sulfur starvation and endocytosed upon the addition of sulfate. We reveal Sul1,2-dependent activation of PKA targets upon sulfate-induced exit from growth arrest after sulfur starvation. We provide two major arguments in favor of Sul1 and Sul2 acting as transceptors for signaling to PKA. First, the sulfate analogue, D-glucosamine 2-sulfate, acted as a non-transported agonist of signaling by Sul1 and Sul2. Second, mutagenesis to Gln of putative H+-binding residues, Glu-427 in Sul1 or Glu-443 in Sul2, abolished transport without affecting signaling. Hence, Sul1,2 can function as pure sulfate sensors. Sul1E427Q and Sul2E443Q are also deficient in sulfate-induced endocytosis, which can therefore be uncoupled from signaling. Overall, our data suggest that transceptors can undergo independent conformational changes, each responsible for triggering different downstream processes. The Sul1 and Sul2 transceptors are the first identified plasma membrane sensors for extracellular sulfate. High affinity transporters induced upon starvation for their substrate may generally act as transceptors during exit from starvation. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc
The Gap1 general amino acid permease acts as an amino acid sensor for activation of protein kinase A targets in the yeast Saccharomyces cerevisiae
Glucose-induced hyperaccumulation of cAMP and absence of glucose repression in yeast strains with induced activity of cAMP-dependent protein kinase.
Addition of glucose or related fermentable sugars to derepressed cells of the yeast Saccharomyces cerevisiae triggers a RAS-mediated cyclic AMP (cAMP) signal that induces a protein phosphorylation cascade. In yeast mutants (tpk1w1, tpk2w1, and tpk3w1) containing reduced activity of cAMP-dependent protein kinase, fermentable sugars, as opposed to nonfermentable carbon sources, induced a permanent hyperaccumulation of cAMP. This finding confirms previous conclusions that fermentable sugars are specific stimulators of cAMP synthesis in yeast cells. Despite the huge cAMP levels present in these mutants, deletion of the gene (BCY1) coding for the regulatory subunit of cAMP-dependent protein kinase severely reduced hyperaccumulation of cAMP. Glucose-induced hyperaccumulation of cAMP was also observed in exponential-phase glucose-grown cells of the tpklw1 and tpk2w1 strains but not the tpk3w1 strain even though addition of glucose to glucose-repressed wild-type cells did not induce a cAMP signal. Investigation of mitochondrial respiration by in vivo 31P nuclear magnetic resonance spectroscopy showed the tpk1w1 and tpk2w1 strains, to be defective in glucose repression. These results are consistent with the idea that the signal transmission pathway from glucose to adenyl cyclase contains a glucose-repressible protein. They also show that a certain level of cAMP-dependent protein phosphorylation is required for glucose repression. Investigation of the glucose-induced cAMP signal and glucose-induced activation of trehalase in derepressed cells of strains containing only one of the wild-type TPK genes indicates that the transient nature of the cAMP signal is due to feedback inhibition by cAMP-dependent protein kinase
Glucose-triggered signalling in Saccharomyces cerevisiae: different requirements for sugar phosphorylation between cells grown on glucose and those grown on non-fermentable carbon sources.
The Saccharomyces cerevisiae Sko1p transcription factor mediates HOG pathway-dependent osmotic regulation of a set of genes encoding enzymes implicated in protection from oxidative damage
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