Yeast sphingolipids: recent developments in understanding biosynthesis, regulation, and function

Abstract

Sphingolipids function as required membrane components of virtually all eukaryotic cells. Data indicate that members of the sphingolipid family of lipids, including sphingoid bases, sphingoid base phosphates, ceramides, and complex sphingolipids, serve vital functions in cell biology by both direct mechanisms (e.g., binding to G-protein coupled receptors to transduce an extracellular signal) and indirect mechanisms (e.g., facilitating correct intracellular protein transport). Because of the diverse roles these lipids play in cell biology, it is important to understand not only their biosynthetic pathways and regulation of sphingolipid synthesis, but also the mechanisms by which some sphingolipid species with specific functions are modified or converted to other sphingolipid species with alternate functions. Due to many factors including ease of culture and genetic modification, and conservation of major sphingolipid metabolic pathways, Saccharomyces cerevisiae has served as an ideal model system with which to identify enzymes of sphingolipid biosynthesis and to dissect sphingolipid function. Recent exciting developments in sphingolipid synthesis, transport, signaling, and overall biology continue to fuel vigorous investigation and inspire investigations in mammalian sphingolipid biology.

Scheme 1

Major pathways of sphingolipid metapolism in Saccharomyces cerevisiae