Identification of a Form of Acyl-CoA:Cholesterol Acyltransferase Specific to Liver and Intestine in Nonhuman Primates *

摘要: The present study demonstrates that two different forms of the intracellular cholesterol esterification enzyme acyl-CoA:cholesterol acyltransferase (ACAT) are in nonhuman primate hepatocyte; one is similar to originally cloned from human genomic DNA, here termed ACAT1, while a second gene product, ACAT2, reported here. ACAT2 product was an African green monkey liver cDNA library. Sequence analysis isolated, full-length clone identified open reading frame encoding 526-amino acid protein with essentially no sequence similarity ACAT1 over N-terminal 101 amino acids but 57% identity predicted remaining 425 acids. Transfection into mammalian cell types resulted production abundant ACAT activity which sensitive inhibitors. Northern blot showed mRNA expressed primarily and intestine monkeys. In contrast, almost all tissues examined. Topologic predictions indicates it has seven trans-membrane domains configuration places putative active site lumen endoplasmic reticulum. This orientation reticulum membrane, addition its expression only intestine, suggests this may have as primary function, secretion cholesteryl esters apoB-containing lipoproteins.