New insights into the roles of phosphoinositides and inositol polyphosphates in yeast

During the past half century, we have progressed from simply viewing myo-inositol-containing glycerophospholipids as quantitatively minor membrane constituents to the present, very striking, situation in which more and more important cellular functions are being assigned to a plethora of phosphorylated derivatives of inositol and phosphatidylinositol. Two such examples are discussed briefly: the activation by environmental stresses of the single phosphoinositidase C of yeast, which is related to the phospholipase C δs of other eukaryotes, and the involvement of PtdIns(3,5)P₂ in endomembrane trafficking.