Vance Jean E, Steenbergen Rineke
Canadian Institutes for Health Research, Group on Molecular and Cell Biology of Lipids, 332 HMRC, University of Alberta, Edmonton, Canada AB T6G 2S2.
Prog Lipid Res. 2005 Jul;44(4):207-34. doi: 10.1016/j.plipres.2005.05.001.
Phosphatidylserine (PS) is a quantitatively minor membrane phospholipid that is synthesized by prokaryotic and eukaryotic cells. In this review we focus on genes and enzymes that are involved in PS biosynthesis in bacteria, yeast, plants and mammalian cells and discuss the available information on the regulation of PS biosynthesis in these organisms. The enzymes that synthesize PS are restricted to endoplasmic reticulum membranes in yeast and mammalian cells, yet PS is widely distributed throughout other organelle membranes. Thus, mechanisms of inter-organelle movement of PS, particularly the transport of PS from its site of synthesis to the site of PS decarboxylation in mitochondria, are considered. PS is normally asymmetrically distributed across the membrane bilayer, thus the mechanisms of transbilayer translocation of PS, particularly across the plasma membrane, are also discussed. The exposure of PS on the outside surface of cells is widely believed to play a key role in the removal of apoptotic cells and in initiation of the blood clotting cascade. PS is also the precursor of phosphatidylethanolamine that is made by PS decarboxylase in bacteria, yeast and mammalian cells. Furthermore, PS is required as a cofactor for several important enzymes, such as protein kinase C and Raf-1 kinase, that are involved in signaling pathways.
磷脂酰丝氨酸（PS）是一种在数量上占比小的膜磷脂，由原核细胞和真核细胞合成。在本综述中，我们重点关注细菌、酵母、植物和哺乳动物细胞中参与PS生物合成的基因和酶，并讨论这些生物体中PS生物合成调控的现有信息。在酵母和哺乳动物细胞中，合成PS的酶局限于内质网膜，但PS广泛分布于其他细胞器膜中。因此，我们考虑了PS在细胞器间移动的机制，特别是PS从其合成位点到线粒体中PS脱羧位点的运输。PS通常不对称地分布在膜双层中，因此也讨论了PS跨双层转运的机制，特别是跨质膜的转运。人们普遍认为，PS在细胞外表面的暴露在凋亡细胞的清除和凝血级联反应的启动中起关键作用。PS也是细菌、酵母和哺乳动物细胞中由PS脱羧酶合成的磷脂酰乙醇胺的前体。此外，PS是几种重要酶（如参与信号通路的蛋白激酶C和Raf-1激酶）的辅助因子。
