Coupling between phosphatidylinositol metabolism and cdc 28 gene product of Saccharomyces cerevisiae: on the possible mechanism of cdc 28 gene action

Abstract

It was shown that the decrease in phosphatidylinositol (PI) content in cdc 28 G₁-cells was due to a defect in inositol transport. This decrease in inositol transport was linked to microtubular function which was evident by the effect of a microtubular disrupting agent (colcemid) on inositol transport in stationary phase A364A cells. The involvement of PI in yeast G₁ phase was further substantiated by the observation that o-phenanthroline, which blocks yeast cells in G₁ phase, could inhibit inositol transport and PI levels as well. It is proposed that the regulation of PI metabolism is mediated by the gene cdc 28 and that microtubules may play a major role in the mechanism of action of this gene product.