Deborah J. Allen

Biosynthesis of Membrane Phospholipids in Yeast — Genetic and Molecular Studies

Baker’s yeast, Saccharomyces cerevisiae, synthesizes its membrane phospholipids by utilizing pathways largely common to other eukaryotes (Figure 1). This simple unicellular organism can easily be manipulated using well established classical genetics and powerful molecular genetics. A large collection of yeast mutants defective in various aspects of biosynthesis and regulation of phospholipids has been collected over the last several decades (Henry, 1982; Nikoloff and Henry, 1991; Swede et al., 1991). These mutants permit the phospholipid content of the yeast membrane to be manipulated to a substantial degree. Much progress has been made recently in purifying the phospholipid biosynthetic enzymes from yeast and in cloning the structural genes encoding them (Carman and Henry, 1989). Several genes involved in regulation of phospholipid biosynthesis have also been cloned (Hoshizaki et al., 1990; White et al., 1991b). Thus, in yeast, it is now possible to explore the regulation and biosynthesis of phospholipids at a level of sophistication not yet possible in any other eukaryotic organism.