Omega-3 fatty acids and the expression of membrane proteins: Emphasis on molecules of immunologic importance

Omega-3 (omega3) fatty acids are associated with a variety of health benefi ts from normal neurologic development and vision, to heart disease, arthrit is and cancer. The omega3 fatty acid docosahexaenoic acid in particular acc umulates in biological membranes and there may serve either structural or s ubstrate functions. Proteins resident in or associated with membranes are l ikely to be influenced by changes in their lipid environment. The mechanism s through which omega3 fatty acids exert their influence over proteins are not always clear, and may include direct interactions that induce conformat ional change, formation of membrane lipid microdomains of unique compositio n; modulation of eicosanoid production; participation in oxidation; and alt eration of gene expression. Much of the complexity of this area stems from the often divergent effects that omega3 fatty acids have on different cell types in different states of activation. Here I present a sampling of prote ins involved in various functions including adhesion, immunologic recogniti on, and signal transduction; the emphasis is on cells and processes of the immune system. Included are effects of free fatty acids and of fatty acyl c hains esterified into phospholipids, and phenomena that appear unique to on e or more omega3 fatty acids or that are common to several different fatty acid classes. Understanding basic mechanisms of w3 fatty acid action, for e xample, on structure and function of membrane proteins will assist us in us ing these dietary components more effectively for human health.