An allostatic control of membrane lipid composition by SREBP1.

The maintenance of membrane lipid composition within strict limits is critical to maintain optimum cellular function. The biophysical properties of the membrane can be influenced among other factors by the saturation/unsaturation of the phospholipid fatty acyl chain. The rate-limiting enzyme in unsaturated fatty acid biosynthesis is the desaturase enzyme which in turn is regulated by the lipid transcription factor sterol regulatory element binding protein (SREBP1). In this review, we collect some evidence suggesting SREBP1 network as an important allostatic regulator necessary to maintain the pool of unsaturated fatty acid lipid species that can be incorporated into biological membranes. Copyright 2010 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.