The molecular basis of abetalipoproteinemia.
Abetalipoproteinemia is a recessive genetic disease in humans characterized by the virtual absence of apolipoprotein (apo)B and apoB-containing lipoproteins in plasma. Microsomal triglyceride transfer protein (MTP), a resident lipid transfer protein within the endoplasmic reticulum of hepatocytes and enterocytes, has been shown to be absent in enterocytes from subjects with this disease. MTP is a heterodimer of a unique large subunit and protein disulfide isomerase. It has been demonstrated that the absence of MTP in abetalipoproteinemia is secondary to mutations in the gene for the large subunit of MTP. Thus, mutations in the gene for the large subunit of MTP are a cause of abetalipoproteinemia, which indicates that the MTP is a necessary component for the assembly and secretion of apoB-containing lipoproteins from the liver and intestine.
Gregg
R E
RE
Department of Metabolic Diseases, Bristol-Myers Squibb Pharmaceutical Research Institute, Princeton, New Jersey.
Wetterau
J R
JR
D000012:Abetalipoproteinemia / Q000235:genetics*; D001055:Apolipoproteins B / Q000172:deficiency; D002352:Carrier Proteins / Q000235:genetics*; D053480:Cholesterol Ester Transfer Proteins; D004721:Endoplasmic Reticulum / Q000378:metabolism; D006023:Glycoproteins; D006801:Humans; D007422:Intestines / Q000648:ultrastructure; D008099:Liver / Q000648:ultrastructure; D009154:Mutation
D001055:Apolipoproteins B; C506642:CETP protein, human; D002352:Carrier Proteins; D053480:Cholesterol Ester Transfer Proteins; D006023:Glycoproteins