Phosphatidylinositol biosynthesis: Biochemistry and regulation

Phosphatidylinositol (PI) is a ubiquitous membrane lipid in eukaryotes. It is becoming increasingly obvious that PI and its metabolites play a myriad of very diverse roles in eukaryotic cells. The Saccharomyces cerevisiae PISI gene is essential and encodes PI synthase, which is required for the synthesis of PI. Recently, PISI expression was found to be regulated in response to carbon source and oxygen availability. It is particularly significant that the promoter elements required for these responses are conserved evolutionarily throughout the Saccharomyces genus. In addition, several genome-wide strategies coupled with more traditional screens suggest that several other factors regulate PISI expression. The impact of regulating PISI expression on PI synthesis will be discussed along with the possible role(s) that this may have on diseases such as cancer. (c) 2005 Elsevier B.V. All rights reserved.