Premium
The human MDR3 P‐glycoprotein promotes translocation of phosphatidylcholine through the plasma membrane of fibroblasts from transgenic mice
Author(s) -
Smith Alexander J.,
Timmermans-Hereijgers Johanna L.P.M.,
Roelofsen Ben,
Wirtz Karel W.A.,
van Blitterswijk Wim J.,
Smit Jaap J.M.,
Schinkel Alfred H.,
Borst Piet
Publication year - 1994
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(94)01135-4
Subject(s) - genetically modified mouse , phosphatidylcholine , membrane glycoproteins , p glycoprotein , secretion , transgene , microbiology and biotechnology , glycoprotein , biology , membrane protein , chemistry , membrane , biochemistry , phospholipid , gene , multiple drug resistance , antibiotics
The mouse mdr2 P‐glycoprotein (P‐gp) and its human MDR3 homologue are present in high concentrations in the canalicular membrane of hepatocytes. Mice lacking this protein are unable to secrete phosphatidylcholine (PC) into bile, suggesting that this P‐gp is a PC translocator. We have tested this in fibroblasts from transgenic mice expressing the MDR 3 gene under a vimentin promoter. Transgenic and control fibroblasts were incubated with [ 14 C]choline to label PC. When the labeled cells were incubated with a PC transfer protein and acceptor liposomes, transfer of radioactive PC was enhanced in transgenic cells relative to the wild type controls. We conclude that the MDR3 P‐glycoprotein is able to promote the transfer of PC from the inner to the outer leaflet of the plasma membrane, supporting the idea that this protein functions as a PC flippase.