title: Cellular localization and interaction of ABCA1 and caveolin-1 in aortic endothelial cells after HDL incubation.
abstract: The goal of this study was to investigate the cellular localization and the interaction between caveolin-1 and ABCA1 in cholesterol-loaded aortic endothelial cells after HDL incubation. Immunofluorescence confocal microscopy showed that ABCA1 was found primarily on the cell surface, whereas caveolin-1 was revealed on the cell surface and in the cytoplasm. The HDL appeared to colocalize with ABCA1 and caveolin-1 on the cell surface. No free HDL was revealed in the cytoplasm. The HDL was colocalized neither with early endosome marker (CD71) nor with late endosome marker (LAMP2). The chemical cross-linking and immunoprecipitation analysis revealed that ABCA1 binds directly to both HDL and caveolin-1, whereas HDL does not bind directly to caveolin-1. The studies provide evidence for a direct interaction between ABCA1 and HDL, ABCA1 and caveolin-1, but not HDL and caveolin-1, indicating that ABCA1 may act as a structural platform between HDL and caveolin-1 on the cell surface during cellular cholesterol efflux.
authors.affiliation: Department of Life Science, Life Science Research Center, Tunghai University, Taichung, Taiwan, ROC.
authors.forename: Wei-Ting
authors.initials: WT
authors.lastname: Chao
authors.forename: Shu-Huai
authors.initials: SH
authors.lastname: Tsai
authors.forename: Yu-Chun
authors.initials: YC
authors.lastname: Lin
authors.forename: Wei-Wen
authors.initials: WW
authors.lastname: Lin
authors.forename: Vivian C
authors.initials: VC
authors.lastname: Yang
mesh_terms: D064286:ATP Binding Cassette Transporter 1; D018528:ATP-Binding Cassette Transporters / Q000378:metabolism*; D000818:Animals; D001013:Aorta, Thoracic / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D001693:Biological Transport, Active; D051242:Caveolin 1; D022461:Caveolins / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D002784:Cholesterol / Q000378:metabolism; D011992:Endosomes / Q000378:metabolism; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000378:metabolism*; D008075:Lipoproteins, HDL / Q000378:metabolism / Q000494:pharmacology*; D008954:Models, Biological; D011485:Protein Binding; D051381:Rats; D013347:Subcellular Fractions / Q000378:metabolism
chemical_list: D064286:ATP Binding Cassette Transporter 1; D018528:ATP-Binding Cassette Transporters; C495537:Cav1 protein, rat; D051242:Caveolin 1; D022461:Caveolins; D008075:Lipoproteins, HDL; D002784:Cholesterol