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Titolo:
INVOLVEMENT OF DISTINCT G-PROTEINS, GPA2 AND RAS, IN GLUCOSE-INDUCED AND INTRACELLULAR ACIDIFICATION-INDUCED CAMP SIGNALING IN THE YEAST SACCHAROMYCES-CEREVISIAE
Autore:
COLOMBO S; MA PS; CAUWENBERG L; WINDERICKX J; CRAUWELS M; TEUNISSEN A; NAUWELAERS D; DEWINDE JH; GORWA MF; COLAVIZZA D; THEVELEIN JM;
Indirizzi:
KATHOLIEKE UNIV LEUVEN,LAB MOL CELBIOL,KARDINAAL MERCIERLAAN 92 B-3001 LEUVEN FLANDERS BELGIUM KATHOLIEKE UNIV LEUVEN,LAB MOL CELBIOL B-3001 LEUVEN FLANDERS BELGIUM TECH UNIV DARMSTADT,INST MIKROBIOL & GENET D-64287 DARMSTADT GERMANY LESAFFRE DEV SA F-57906 MARCQ EN BAROEUL FRANCE
Titolo Testata:
EMBO journal (Print)
fascicolo: 12, volume: 17, anno: 1998,
pagine: 3326 - 3341
SICI:
0261-4189(1998)17:12<3326:IODGGA>2.0.ZU;2-#
Fonte:
ISI
Lingua:
ENG
Soggetto:
GTPASE-ACTIVATING PROTEIN; CYCLIC AMP PATHWAY; CDC25 GENE-PRODUCT; ADENYLATE-CYCLASE PATHWAY; SCHIZOSACCHAROMYCES-POMBE; RESERVE CARBOHYDRATE; DEPOLARIZING AGENTS; FERMENTABLE SUGARS; MOLECULAR-CLONING; VEGETATIVE CELLS;
Keywords:
ACIDIFICATION; CAMP SIGNALING; GPA2; GLUCOSE; RAS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
97
Recensione:
Indirizzi per estratti:
Citazione:
S. Colombo et al., "INVOLVEMENT OF DISTINCT G-PROTEINS, GPA2 AND RAS, IN GLUCOSE-INDUCED AND INTRACELLULAR ACIDIFICATION-INDUCED CAMP SIGNALING IN THE YEAST SACCHAROMYCES-CEREVISIAE", EMBO journal (Print), 17(12), 1998, pp. 3326-3341

Abstract

Adenylate cyclase activity in Saccharomyces cerevisiae is dependent on Ras proteins. Both addition of glucose to glucose-deprived (derepressed) cells and intracellular acidification trigger an increase in the cAMP level in vivo, We show that intracellular acidification, but not glucose, causes an increase in the GTP/GDP ratio on the Ras proteins independent of Cdc25 and Sdc25. Deletion of the GTPase-activating proteins Ira1 and Ira2, or expression of the RAS2(val19) allele, causes an enhanced GTP/GDP basal ratio and abolishes the intracellular acidification-induced increase. In the iral Delta ira2 Delta strain, intracellular acidification still triggers a cAMP increase. Glucose also did notcause an increase in.the GTP/GDP ratio in a strain with reduced feedback inhibition of cAMP synthesis. Further investigation indicated thatfeedback inhibition by cAPK on cAMP synthesis acts independently of changes in the GTP/GDP ratio on Ras. Stimulation by glucose was dependent on the G alpha-protein Gpa2, whose deletion confers the typical phenotype associated with a reduced cAMP level: higher heat resistance, ahigher level of trehalose and glycogen and elevated expression of STRE-controlled genes. However, the typical fluctuation in these characteristics during diauxic growth on glucose was still present. Overexpression of Ras2(val19) inhibited both the acidification- and glucose-induced cAMP increase even in a protein kinase A-attenuated strain. Our results suggest that intracellular acidification stimulates cAMP synthesis in vivo at least through activation of the Ras proteins, while glucose acts through the Gpa2 protein. Interaction of Ras2(val19),vith adenylate cyclase apparently prevents its activation by both agonists.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 04/07/20 alle ore 05:21:53