Abstract
Metabolic control and inter-organelle transport of phospholipids are essential events for membrane biogenesis in eukaryotes. The synthesis of the phospholipid phosphatidylserine (PS) in eukaryotes occurs in the endoplasmic reticulum (ER) and a subdomain of this organelle known as the mitochondria-associated membrane (MAM). In cultured mammalian cells, the PS synthesis is inhibited by exogenous PS, and this feedback control occurs not through regulation of expression of PS synthase genes, but through inhibition of PS synthases by PS. Meanwhile PS synthesized in ER/MAM is transported to various organelles including the plasma membranes, mitochondria, and Golgi. A significant body of data suggests that the inter-organelle transport of PS occurs at zones of contact between donor and acceptor membranes. Recent studies have identified some of the lipids and proteins that participate inthe PS transport from ER/MAM to mitochondria or Golgi. In this review, I describe the current understanding of the regulation of PS biosynthesis in mammalian cells and the transport of PS from ER/MAM to mitochondria or Golgi in mammalian and yeast cells.
