Secretion of apolipoprotein B-containing lipoproteins from HeLa cells is dependent on expression of the microsomal triglyceride transfer protein and is regulated by lipid availability.
AUTOR(ES)
Gordon, D A
RESUMO
To elucidate the role of the microsomal triglyceride transfer protein (MTP) in lipoprotein assembly, MTP and apolipoprotein B-53 (apoB 53; the N-terminal 53% of apoB) were expressed in HeLa cells. The results showed that apoB-53 could be expressed in HeLa cells with or without expression of MTP. In contrast, efficient secretion of apoB-53 required expression of MTP. Ultracentrifugal density flotation analysis showed that apoB-53 was secreted predominantly as a particle with the density of high density lipoprotein. An essentially identical apoB-53 particle density distribution was obtained after transient expression of apoB-53 in McArdle RH-7777 rat hepatoma cells. The mass of apoB-53 secreted was greater, and the flotation density was lower, from cells fed lipid, suggesting that apoB secretion in HeLa cells was regulated by lipid availability, similar to what has been described for lipoprotein-producing cell lines. These results indicate that MTP is necessary and sufficient to direct the regulated secretion of apoB-53 in HeLa cells.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=44455Documentos Relacionados
- Selective removal of apolipoprotein B-containing serum lipoproteins from blood plasma.
- Mechanisms of enhanced cholesteryl ester transfer from high density lipoproteins to apolipoprotein B-containing lipoproteins during alimentary lipemia.
- Genetic evidence for a role of adiponutrin in the metabolism of apolipoprotein B-containing lipoproteins
- An inhibitor of the microsomal triglyceride transfer protein inhibits apoB secretion from HepG2 cells.
- A nuclear cap binding protein from HeLa cells.
