| Autor: |
Nicole A. Braun, Peter J. Mohler, Karl H. Weisgraber, Alyssa H. Hasty, MacRae F. Linton, Patricia G. Yancey, Yan Ru Su, Sergio Fazio, Larry L. Swift |
| Jazyk: |
angličtina |
| Rok vydání: |
2006 |
| Předmět: |
|
| Zdroj: |
Journal of Lipid Research, Vol 47, Iss 6, Pp 1176-1186 (2006) |
| Druh dokumentu: |
article |
| ISSN: |
0022-2275 |
| DOI: |
10.1194/jlr.M500503-JLR200 |
| Popis: |
We have investigated apolipoprotein E (apoE) recycling in Chinese hamster ovary (CHO) cells, a peripheral cell that does not produce lipoproteins or express apoE. Using a pulse-chase protocol in which cells were pulsed with 125I-apoE-VLDL and chased for different periods, ∼30% of the apoE internalized during the pulse was resecreted within a 4 h chase in a relatively lipid-free state. The addition of lysosomotropic agents or brefeldin A had no effect on apoE recycling. Unlike previous results with hepatocytes and macrophages, neither apoA-I nor upregulation of ABCA1 stimulated apoE recycling. However, cyclodextrin, which extracts cholesterol from plasma membrane lipid rafts, increased recycling. Confocal studies revealed that apoE, internalized during a 1 h pulse, colocalizes with early endosomal antigen-1, Rab5, Rab11a, and lysobisphosphatidic acid but not with lysosomal-associated membrane protein-1. Colocalization of apoE and Rab11a persisted even after cells had been chased for 1 h, suggesting a pool of apoE within the endosomal recycling compartment (ERC). Our data suggest that apoE recycling in CHO cells is linked to cellular cholesterol removal via the ERC and phospholipid-containing acceptors in a pathway alternative to the ABCA1-apoA-I axis. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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