Functional incorporation of P-glycoprotein into Xenopus oocyte plasma membrane fails to elicit a swelling-evoked conductance

• Published in: Biochemical and biophysical research communications 1997-08, Vol.237 (2), p.407-412
• Main Authors: Aleu, J, Ivorra, I, Lejarreta, M, Gonzalez-Ros, J M, Morales, A, Ferragut, J A
• Format: Article
• Language: English
• Subjects: Animals; ATP-Binding Cassette, Sub-Family B, Member 1 - metabolism; Cell Line; Cell Membrane - metabolism; Drug Resistance, Multiple; Leukemia L1210 - metabolism; Leukemia L1210 - pathology; Membrane Potentials; Mice; Oocytes - metabolism; Oocytes - physiology; Xenopus
• ISSN: 0006-291X
• DOI: 10.1006/bbrc.1997.7150

Microinjecton of Xenopus oocytes with P-glycoprotein-containing membranes from multidrug resistant cells following a recently published procedure resulted in the transplantation of the protein to the plasma membrane of the oocytes and was confirmed by Western blot analysis. These oocytes showed a reduced intracellular accumulation of daunomycin, when compared to uninjected oocytes or to those injected with membrane vesicles lacking P-glycoprotein, thus indicating that the protein had been incorporated in a transport-competent form. On the other hand, transplantation of P-glycoprotein to the oocyte membrane did not significantly change either the appearance or the properties of swelling-elicited membrane conductance with respect to those determined in oocytes either uninjected or injected with membranes lacking P-glycoprotein. These results do not support a role for P-glycoprotein as a swelling-activated chloride channel.