Involvement of membrane-associated proteins in the acute regulation of cellular fatty acid uptake.

The transport of long-chain fatty acids across cellular membranes most likely occurs to some extent by passive diffusion and additionally is facilitated by a number of membrane-associated and cytoplasmic proteins. In this overview we focus on the involvement of the membrane proteins fatty acid translocase (FAT/CD36), plasma membrane fatty acid-binding protein (FABPpm) and fatty acid-transport protein (FATP). Newly obtained evidence is presented that in skeletal muscle, fatty acid uptake is subject to short-term regulation by translocation of FAT/CD36 from intracellular stores to the plasma membrane, analogous to the regulation of muscular glucose uptake by GLUT-4 translocation. These new findings establish a significant role of membrane-associated proteins in the cellular fatty acid-uptake process. Possible implications for the uptake and transport of long-chain fatty acids by the brain are discussed.