Effects of unsaturated fatty acids on cell membrane functions

Abstract

Biological membranes consist of lipid bilayers composed primarily of phospholipids and cholesterol. Proteins with important membrane functions, such as enzymes, receptors and transporters are enclosed in the lipid bilayer. A basic question is whether interactions with lipids in the bilayer can modulate the activity of membrane proteins. From the standpoint of cellular physiology and metabolic regulation, a critical point has been whether changes in membrane lipid composition actually occur in living cells as a response to changes in the lipid availability, and if so, whether the changes are of sufficient magnitude to influence membrane functions. During the last decade an extensive amount of information regarding these issues has been obtained, especially from studies with liposomes and mammalian cells in culture. The purpose of this review is briefly to describe how changes in membrane lipids, especially fatty acid composition, may modulate physiological properties of membranes, such as fluidity, and cellular functions.