« Previous AbstractFunctional characterization of two 20beta-hydroxysteroid dehydrogenase type 2 homeologs from Xenopus laevis reveals multispecificity    Next Abstract"Fully automated, high-throughput instrumentation for measuring the delta13C value of methane and application of the instrumentation to rice paddy samples" »

Mol Microbiol

Title:		Hexose phosphorylation and the putative calcium channel component Mid1p are required for the hexose-induced transient elevation of cytosolic calcium response in Saccharomyces cerevisiae
Author(s):		Tokes-Fuzesi M; Bedwell DM; Repa I; Sipos K; Sumegi B; Rab A; Miseta A;
Address:		"Department of Clinical Chemistry, Faculty of Medicine, Pecs University, 13 Ifjusag u., Pecs 7624, Hungary"
Journal Title:		Mol Microbiol
Year:		2002
Volume:		44
Issue:		5
Page Number:		1299 - 1308
DOI:		10.1046/j.1365-2958.2002.02956.x
ISSN/ISBN:		0950-382X (Print) 0950-382X (Linking)
Abstract:		"Saccharomyces cerevisiae responds to environ-mental stimuli such as an exposure to pheromone or to hexoses after carbon source limitation with a transient elevation of cytosolic calcium (TECC) response. In this study, we examined whether hexose transport and phosphorylation are necessary for the TECC response. We found that a mutant strain lacking most of the known hexose transporters was unable to carry out the TECC response when exposed to glucose. A mutant strain that lacked the ability to phosphorylate glucose was unable to respond to glucose addition, but displayed a normal TECC response after the addition of galactose. These results indicate that hexose uptake and phosphorylation are required to trigger the hexose-induced TECC response. We also found that the TECC response was significantly smaller than normal when the level of environmental calcium was reduced, and was abolished in a mid1 mutant that lacked a subunit of the high-affinity calcium channel of the yeast plasma membrane. These results indicate that most or all of the TECC response is mediated by an influx of calcium from the extracellular space. Our results indicate that this transient increase in plasma membrane calcium permeability may be linked to the accumulation of Glc-1-P (or a related glucose metabolite) in yeast"
Keywords:		"Aequorin/genetics/metabolism Calcium/*metabolism Calcium Channels/*metabolism Fungal Proteins/genetics/*metabolism Genes, Reporter Glucose-6-Phosphate/metabolism Glucosephosphates/metabolism Hexoses/*metabolism Membrane Glycoproteins/genetics/*metabolism;"
Notes:		"MedlineTokes-Fuzesi, Margit Bedwell, David M Repa, Imre Sipos, Katalin Sumegi, Balazs Rab, Andras Miseta, Attila eng England 2002/05/25 Mol Microbiol. 2002 Jun; 44(5):1299-308. doi: 10.1046/j.1365-2958.2002.02956.x"