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Caveolin-1-dependent and -independent membrane domains.
- Source :
-
Journal of lipid research [J Lipid Res] 2009 Aug; Vol. 50 (8), pp. 1609-20. Date of Electronic Publication: 2008 Dec 12. - Publication Year :
- 2009
-
Abstract
- Lipid rafts defined as cholesterol- and sphingomyelin-rich domains have been isolated from different cell types that vary greatly in their lipid profiles. Here, we investigated the contribution of the structural protein caveolin-1 (Cav1) to the overall lipid composition and domain abundance in mouse embryonic fibroblasts (MEFs) from wild-type (WT) or Cav1-deficient (Cav1(-/-)) animals. Our findings show that Cav1 expression had no effect on free (membrane-associated) cholesterol levels. However, Cav1(-/-)-deficient cells did have a higher proportion of sphingomyelin, decreased abundance of unsaturated phospholipids, and a trend toward shorter fatty acid chains in phosphatidylcholine. We isolated detergent-resistant membranes (DRMs), nondetergent raft domains (NDR), and cholesterol oxidase (CO)-sensitive domains and assessed the abundance of ordered domains in intact cells using the fluorescent dye Laurdan. Despite differences in phospholipid composition, we found that cholesterol levels in DRMs, NDR, and CO-sensitive domains were similar in both cell types. The data suggest that Cav1 is not required to target cholesterol to lipid rafts and that CO does not specifically oxidize caveolar cholesterol. In contrast, the abundance of ordered domains in adherent cells is reduced in Cav1(-/-) compared with WT MEFs, suggesting that cell architecture is critical in maintaining Cav1-induced lipid rafts.
- Subjects :
- Animals
Caveolae
Caveolin 1 analysis
Caveolin 1 deficiency
Caveolin 2 analysis
Cell Membrane Structures chemistry
Cells, Cultured
Cholesterol analysis
Cholesterol Esters analysis
Cholesterol Oxidase metabolism
Fatty Acids analysis
Female
Male
Mice
Mice, Knockout
Phosphatidylcholines analysis
Proto-Oncogene Proteins c-yes metabolism
Sphingomyelins analysis
Caveolin 1 physiology
Membrane Microdomains chemistry
Phospholipids analysis
Subjects
Details
- Language :
- English
- ISSN :
- 1539-7262
- Volume :
- 50
- Issue :
- 8
- Database :
- MEDLINE
- Journal :
- Journal of lipid research
- Publication Type :
- Academic Journal
- Accession number :
- 19074371
- Full Text :
- https://doi.org/10.1194/jlr.M800601-JLR200