EXPRESSION CLONING AND CHARACTERIZATION OF A NOVEL ADIPOCYTE LONG-CHAIN FATTY-ACID TRANSPORT PROTEIN

Long chain fatty acids (LCFAs) are an important energy substrate used by cardiac myocytes and other cells, but the mechanism whereby these m olecules cross the plasma membrane is poorly understood. We used an ex pression cloning strategy and a cDNA library from 3T3-L1 adipocytes to identify a cDNA that, when expressed in cultured cells, augments upta ke of LCFAs. This cDNA encodes a novel 646 amino acid fatty acid trans port protein (FATP) with six predicted membrane-spanning regions and t hat is integrally associated with membranes. Immunocytochemistry and s ubcellular fractionation of 3T3-L1 adipocytes show that FATP is locali zed to the plasma membrane. We propose that FATP is a plasma membrane transporter for LCFAs.