The glucose-induced polyphosphoinositides turnover in Saccharomyces cerevisiae is not dependent on the CDC25-RAS mediated signal transduction pathway

Recently the polyphosphoinositides (PI) turnover has been related to the control of growth and cell cycle also in Saccharomvces cerevisiae , and the RAS2 and RAS1 gene products have been shown to be involved in the stimulation of PI turnover in G0/G1 arrested yeast cells. Here we show that addition of glucose to previously glucose-starved cells, stimulates the PI turnover with fast kinetics also in yeast cells that were not arrested in the G0/G1 phase of the cell cycle. In addition PI turnover is equally stimulated in temperature sensitive cdc25-1 and cdc25-5 strains at restrictive temperature, as well as in ras1, ras2 strain, suggesting that PI turnover stimulation is not dependent on the CDC25-RAS mediated signal transduction pathway.