Yeagle P L
Department of Biochemistry, State University of New York, Buffalo 14214.
FASEB J. 1989 May;3(7):1833-42.
Recent studies of structure-function relationships in biological membranes have revealed fundamental concepts concerning the regulation of cellular membrane function by membrane lipids. Considerable progress has been made in understanding the roles played by two membrane lipids: cholesterol and phosphatidyl-ethanolamine. Cholesterol has been shown to regulate ion pumps, which in some cases show an absolute dependence on cholesterol for activity. These studies suggest that an essential role that cholesterol plays in mammalian cell biology is to enable crucial membrane enzymes to provide function necessary for cell survival. Studies of phosphatidylethanolamine regulation of membrane protein activity and regulation of membrane morphology led to hypotheses concerning the roles for this particular lipid in biological membranes. New information on lipid-protein interactions and on the nature of the lipid head groups has permitted the development of mechanistic hypotheses for the regulation of membrane protein activity by phosphatidyl-ethanolamine. In addition, intermediates in the lamellar-nonlamellar phase transitions of membrane systems containing phosphatidylethanolamine, or other lipids with similar properties, have recently been implicated in facilitating membrane fusion. Finally, studies of transmembrane movement of lipids have provided new insight into the regulation of membrane lipid asymmetry and the biogenesis of cell membranes. These kinds of studies are harbingers of a new generation of progress in the field of cell membranes.
近期对生物膜结构与功能关系的研究揭示了有关膜脂对细胞膜功能调节的基本概念。在理解两种膜脂——胆固醇和磷脂酰乙醇胺所起的作用方面已取得了相当大的进展。胆固醇已被证明可调节离子泵，在某些情况下，离子泵的活性对胆固醇表现出绝对依赖性。这些研究表明，胆固醇在哺乳动物细胞生物学中所起的一个重要作用是使关键的膜酶能够提供细胞存活所需的功能。对磷脂酰乙醇胺对膜蛋白活性的调节以及对膜形态的调节的研究，引发了关于这种特定脂质在生物膜中作用的假说。关于脂-蛋白相互作用以及脂质头部基团性质的新信息，使得人们能够提出关于磷脂酰乙醇胺调节膜蛋白活性的机制假说。此外，含有磷脂酰乙醇胺或其他具有类似性质脂质的膜系统在层状-非层状相变过程中的中间体，最近被认为与促进膜融合有关。最后，对脂质跨膜运动的研究为膜脂不对称性的调节和细胞膜的生物发生提供了新的见解。这类研究预示着细胞膜领域新一代进展的到来。
