ATP-dependent glutathione disulphide transport mediated by the MRP gene-encoded conjugate export pump.
We have previously shown that the multidrug resistance protein (MRP) mediates the ATP-dependent membrane transport of the endogenous glutathione conjugate leukotriene C4 (LTC4) and of structurally related anionic conjugates of lipophilic compounds [Jedlitschky, Leier, Buchholz, Center and Keppler (1994) Cancer Res. 54, 4833-4836; Leier, Jedlitschky, Buchholz, Cole, Deeley and Keppler (1994) J. Biol. Chem. 269, 27807-27810]. We demonstrate in the present study that MRP also mediates the ATP-dependent transport of GSSG, as shown in membrane vesicles from human leukaemia cells overexpressing MRP (HL60/ADR cells) or HeLa cells transfected with an MRP expression vector (HeLa T5 cells) in comparison with the respective parental or control cells. The Km value for ATP-dependent transport of GSSG was 93 +/- 26 microM (mean value +/- S.D., n=5) in membrane vesicles from HeLa T5 cells. GSH, at a concentration of 100 microM, was not a substrate for any significant ATP-dependent MRP-mediated transport. The transport of GSSG was competitively inhibited by LTC4, by the leukotriene D4 receptor antagonist 3-([{3-(2-[7-chloro-2-quinolinyl]ethenyl)phenyl}-{(3-dimethylamino-3- oxopropyl)-thio}-methyl]thio)propanoic acid (MK 571) and by S-decylglutathione, with K1 values of 0.3, 0.6 and 0.7 microM respectively. These studies identify MRP as the membrane glycoprotein which mediates the ATP-dependent export of GSSG from these cells.
Leier
I
I
Division of Tumour Biochemistry, Deutsches Krebsforschungszentrum, Heidelberg, Germany.
Jedlitschky
G
G
Buchholz
U
U
Center
M
M
Cole
S P
SP
Deeley
R G
RG
Keppler
D
D
D018528:ATP-Binding Cassette Transporters / Q000235:genetics* / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism*; D001648:Bile Canaliculi / Q000378:metabolism; D001692:Biological Transport; D002462:Cell Membrane / Q000378:metabolism; D005978:Glutathione / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000378:metabolism; D019803:Glutathione Disulfide; D006367:HeLa Cells; D006801:Humans; D017997:Leukotriene C4 / Q000378:metabolism; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D014316:Tritium; D014407:Tumor Cells, Cultured
D018528:ATP-Binding Cassette Transporters; D000255:Adenosine Triphosphate; D005978:Glutathione; D019803:Glutathione Disulfide; D017997:Leukotriene C4; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D014316:Tritium