cDNA Cloning of Mouse and Human Cholesterol 25-Hydroxylases, Polytopic Membrane Proteins That Synthesize a Potent Oxysterol Regulator of Lipid Metabolism

Oxysterols regulate the expression of genes involved in cholesterol and lipid metabolism and serve as intermediates in cholesterol catabolism. Among the most potent of regulatory oxysterols is 25-hydroxycholesterol, whose biosynthetic enzyme has not yet been isolated. Here, we report the cloning of cholesterol 25-hydroxylase cDNAs from the mouse and human. The encoded enzymes are polytopic membrane proteins of 298 and 272 amino acids,...