P-glycoprotein is localized in caveolae in resistant cells and in brain capillaries.
A significant proportion of P-glycoprotein (P-gp) and caveolin was co-localized in caveolae isolated from resistant (CH(R)C5) cells overexpressing P-gp and from drug-sensitive Chinese hamster ovary cells (AuxB1). The proportion of P-gp and caveolin associated with caveolar microdomains was higher in CH(R)C5 cells grown in the presence of P-gp substrates (cyclosporin A or colchicine) than in untreated CH(R)C5 cells. Coimmunoprecipitation of P-gp and caveolin from CH(R)C5 lysates suggests that there is a physical interaction between them. Furthermore, co-localization of P-gp and caveolin was found in caveolae from brain capillaries, indicating that this association also takes place in vivo.
Demeule
M
M
Laboratoire de Médecine Moléculaire, Centre de Cancérologie Charles Bruneau-UQAM, Département de Chimie-Biochimie, Montréal, Canada.
Jodoin
J
J
Gingras
D
D
Béliveau
R
R
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000098:blood supply*; D016466:CHO Cells; D002196:Capillaries / Q000378:metabolism*; D006224:Cricetinae; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism; D011233:Precipitin Tests; D014407:Tumor Cells, Cultured
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D008565:Membrane Proteins