Fig. 1. Putative model for the effect of n-3 PUFA on lipid rafts.
Lipid rafts are nanoscale regions of the plasma membrane, enriched in cholesterol, sphingomyelin, and phospholipids containing saturated acyl chains. Both transmembrane and peripheral membrane proteins can be localized to lipid rafts. Upon treatment with a combination of n-3 PUFA or DHA alone, these PUFA are incorporated into phospholipids which are inserted into both raft and non-raft regions of the plasma membrane. This results in enhanced clustering of lipid raft regions, which are depleted of cholesterol and sphingomyelin. Additionally, many lipid raft associated proteins “mislocalize” to the bulk membrane domain. This results in a suppression of lipid raft mediated processes, including T-cell activation and downstream signal transduction.