Biological Consequences of Alterations in the Physical Properties of Membranes

Abstract

Membranes serve important functions for cell organization and for the transduction of signals from the external environment to the cell interior. These functions are generally determined by specific molecules in the membrane such as receptors and membrane bound enzymes. The functioning of these receptors and enzymes are modulated by the nature of their physical environment, i.e. the efficiency of signal transduction and the activity of membrane-bound enzymes will be affected by the nature of the membrane surrounding the specific functional sites. In addition, some properties of membranes such as permeability or membrane fusion may not be absolutely dependent on the presence of specific proteins but may also occur by non-specific mechanisms. In this review, we will focus on the modulation of viral fusion, protein kinase C activity and insulin signalling in adipocytes as examples of membrane functions that are modulated by the physical properties of the membrane. An earlier review of our work in this area has recently appeared (Epand, 1990a).