Synthesis and function of hepatic very-low-density lipoprotein

• Published in: Biochemical Society transactions Vol. 32; no. Pt 1; p. 59
• Main Authors: Gibbons, G F, Wiggins, D, Brown, A-M, Hebbachi, A-M
• Format: Journal Article
• Language: English
• Published: England 01.02.2004
• Subjects: Animals; Apolipoproteins B - metabolism; Humans; Lipoproteins, VLDL - biosynthesis; Lipoproteins, VLDL - metabolism; Liver - metabolism; Particle Size; Triglycerides - metabolism
• ISSN: 0300-5127
• DOI: 10.1042/bst0320059

Most of the triacylglycerol (TAG) utilized for the assembly of very-low-density lipoprotein (VLDL) in the secretory apparatus of the hepatocyte is mobilized by lipolysis of the cytosolic TAG pool, followed by re-esterification. The lipases involved include arylacetamide deacetylase and/or triacylglycerol hydrolase. Some of the re-esterified products of lipolysis gain access to an apolipoprotein-B-rich VLDL precursor to form mature VLDL. Some, however, are returned to the cytosolic pool in a process that is stimulated by insulin and inhibited by microsomal triacylglycerol transfer protein (MTP). Phospholipids also contribute to VLDL TAG in a process which involves ADP-ribosylation factor-1 (ARF-1)-mediated activation of phospholipase D. The temporary storage of TAG in the liver, followed by its mobilization and secretion as VLDL, form part of a process by which the liver protects vulnerable body tissues from excess lipotoxic non-esterified ('free') fatty acids in the plasma.