Evidence that during very low density lipoprotein assembly in rat hepatocytes most of the triacylglycerol and phospholipid are packaged with apolipoprotein B in the Golgi complex.
Rat liver lipids were labelled by an intraportal injection of [3H]palmitic acid followed by isolation of rough and smooth endoplasmic reticulum or 'cis' or 'trans'-enriched Golgi fractions. The preparations were separated into membrane and contents and the apolipoprotein B of the content fractions was immunoprecipitated. More than 90% of the labelled triacylglycerol and phospholipid secreted into the blood immunoprecipitated with apolipoprotein B. Under the same experimental conditions 8, 12, 27 and 59% of the lipids of the rough, smooth, 'cis-Golgi' and 'trans-Golgi' contents, respectively, were immunoprecipitated. Thus, the 'trans-Golgi' region appears to be the major intracellular site of assembly of apolipoprotein B with triacylglycerol and phospholipid.
Higgins
J A
JA
Dept of Biochemistry, Sheffield, England.
D000818:Animals; D001055:Apolipoproteins B / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000378:metabolism; D006056:Golgi Apparatus / Q000378:metabolism*; D007163:Immunosorbent Techniques; D007425:Intracellular Membranes / Q000378:metabolism; D007700:Kinetics; D008079:Lipoproteins, VLDL / Q000378:metabolism*; D008099:Liver / Q000378:metabolism* / Q000648:ultrastructure; D008861:Microsomes / Q000378:metabolism; D019308:Palmitic Acid; D010169:Palmitic Acids / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism*; D051381:Rats; D014280:Triglycerides / Q000378:metabolism*; D014316:Tritium
D001055:Apolipoproteins B; D008079:Lipoproteins, VLDL; D010169:Palmitic Acids; D010743:Phospholipids; D014280:Triglycerides; D014316:Tritium; D019308:Palmitic Acid