TRIACYLGLYCEROL IN BIOMEMBRANES

A better knowledge of the biochemical and biophysical properties of ce ll membranes has revealed fundamental concepts concerning the regulati on of cell functions by intrinsic components of the lipid matrix. Memb rane lipids exhibit high chemical heterogeneity, with hundreds of dist inct chemical species; studies of structure-function relationships hav e unraveled new roles for an increasing number of these lipids as dete rminants of membrane structure, anchors for membrane-associated protei ns or signalling agents. Recent observations have confirmed triacylgly cerol (TG) as a quantitatively minor intrinsic membrane component whic h seems to play a specific role in important metabolic events such as cell stimulation or transformation and metastatic processes. The rapid turnover of the acyl chains into TG of cell membranes suggests an act ive metabolism. In the plasma membrane, TG appears to be implicated in the generation of transient non-bilayer domains suspected to be assoc iated with specific cellular events. This paper summarizes the current information on TG metabolism and focuses on the potential role of thi s neutral lipid species on the structure and function of cell membrane s.