Sterol carrier protein-2

The compartmentalization of cholesterol metabolism implies target-specific cholesteroI trafficking between the endoplasmic reticulum, plasma membrane, lysosomes, mitochondria and peroxisomes. One hypothesis has been that sterol carrier protein-2 (SCP2, also known as the non-specific lipid transfer protein) acts in cholesterol transport through the cytoplasm. Recent studies employing gene targeting in mice showed, however, that mice lacking SCP2 and the related putative sterol carrier known as SCPx, develop a defect in peroxisomal P-oxidation. In addition, diminished peroxisomal a-oxidation of phytanic acid (3,7,11,15-tetramethylhexadecanoic acid) in these null mice was attributed to the absence of SCP2 which has a number of properties supporting a function as carrier for fatty acyl-CoAs rather than for sterols. (C) 2000 Elsevier Science B.V. All rights reserved.