MOUSE MICROSOMAL TRIGLYCERIDE TRANSFER PROTEIN LARGE SUBUNIT - CDNA CLONING, TISSUE-SPECIFIC EXPRESSION, AND CHROMOSOMAL LOCALIZATION

Microsomal triglyceride transfer protein (MTP) catalyzes the transfer of triglyceride, cholesteryl ester, and phospholipid between membranes . It is essential for the secretion of apolipoprotein B from the cell. Mutations in MTP are a major cause of abetalipoproteinemia. The mouse is a popular animal model for lipoprotein metabolism. We have cloned and sequenced mouse MTP cDNA. The DNA-deduced amino acid sequence indi cates that mouse MTP contains 894 amino acids; the mouse protein shows 93, 86, and 83% sequence identity to the hamster, human, and bovine s equences, respectively. Northern blot analysis indicates that mouse MT P mRNA is expressed at high levels in the small intestine and at subst antially lower levels in the liver and that it is not detectable in si x other tissues examined. The mouse MTP gene has been localized to the distal region of chromosome 3 by Southern blots of interspecific back cross panels using progeny derived from matings of (C57BL/BJ x SPRET/E i)F1 x SPRET/Ei. Comparison of MTP sequences from human, bovine, hamst er, and mouse indicates that the C-terminal region of MTP is better co nserved than its N-terminal region, (C) 1996 Academic Press, Inc.