Autor(es): Coccetti, Paola ; Tisi, Renata ; Martegani, Enzo ; Teixeira, Leonardo Souza ; Brandão, Rogélio Lopes ; Castro, Ieso de Miranda ; Thevelein, Johan Maria
Data: 2012
Origem: Oasisbr
Assunto(s): Compound 48/80; Saccharomyces cerevisiae; Glucose induction; Signal transduction; Medium acidification
Addition of glucose to glucose-deprived cells of the yeast Saccharomyces cerevisiae triggers rapid turnover of phosphatidylinositol, phosphatidylinositol-phosphate and phosphatidylinositol 4,5-bisphosphate. Glucose stimulation of PI turnover was measured both as an increase in the specific ratio of 32P-labeling and as an increase in the level of diacylglycerol after addition of glucose. Glucose also causes rapid activation of plasma membrane H.-ATPase. We show that in a mutant lacking the PLC1 encoded phospholipase C, both processes were strongly reduced. Compound 48/80, a known inhibitor of mammalian phospholipase C, inhibits both processes. However, activation of the plasma membrane H.- ATPase is only inhibited by concentrations of compound 48/80 that strongly inhibit phospholipid turnover. Growth was inhibited by even lower concentrations. Our data suggest that in yeast cells, glucose triggers through activation of the PLC1 gene product a signaling pathway initiated by phosphatidylinositol turnover and involved in activation of the plasma membrane H.-ATPase.
