Dissecting the role of the Golgi complex and lipid rafts in biosynthetic transport of cholesterol to the cell surface
AUTOR(ES)
Heino, Sanna
FONTE
The National Academy of Sciences
RESUMO
In this study, we compared the transport of newly synthesized cholesterol with that of influenza virus hemagglutinin (HA) from the endoplasmic reticulum to the plasma membrane. The arrival of cholesterol on the cell surface was monitored by cyclodextrin removal, and HA transport was monitored by surface trypsinization and endoglycosidase H digestion. We found that disassembly of the Golgi complex by brefeldin A treatment resulted in partial inhibition of cholesterol transport while completely blocking HA transport. Further, microtubule depolymerization by nocodazole inhibited cholesterol and HA transport to a similar extent. When the partitioning of cholesterol into lipid rafts was analyzed, we found that newly synthesized cholesterol began to associate with low-density detergent-resistant membranes rapidly after synthesis, before it was detectable on the cell surface, and its raft association increased further upon chasing. When cholesterol transport was blocked by using 15°C incubation, the association of newly synthesized cholesterol with low-density detergent-insoluble membranes was decreased and cholesterol accumulated in a fraction with intermediate density. Our results provide evidence for the partial contribution of the Golgi complex to the transport of newly synthesized cholesterol to the cell surface and suggest that detergent-resistant membranes are involved in the process.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=26955Documentos Relacionados
- Lipid rafts function in biosynthetic delivery of proteins to the cell surface in yeast
- Cholesterol, lipid rafts, and disease
- Role of the Golgi complex in the intracellular transport of secretory proteins.
- Golgi-dependent transport of cholesterol to the Chlamydia trachomatis inclusion
- Nef increases the synthesis of and transports cholesterol to lipid rafts and HIV-1 progeny virions