Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
16
pubmed:dateCreated
1996-6-18
pubmed:abstractText
The 190-kDa multidrug resistance protein (MRP) has recently been associated with the transport of cysteinyl leukotrienes and several glutathione (GSH) S-conjugates. In the present study, we have examined the transport of leukotriene C4 (LTC4) in membrane vesicles from MRP-transfected HeLa cells (T14), as well as drug-selected H69AR lung cancer cells which express high levels of MRP. V(max) and K(m) values for LTC4 transport by membrane vesicles from T14 cells were 529 +/- 176 pmol mg(-1) min(-1) and 105 +/- 31 nM, respectively. At 50 nM LTC4, the K(m) (ATP) was 70 micron. Transport in T14 vesicles was osmotically-sensitive and was supported by various nucleoside triphosphates but not by non- or slowly-hydrolyzable ATP analogs. LTC4 transport rates in membrane vesicles derived from H69AR cells and their parental and revertant variants were consistent with their relative levels of MRP expression. A 190-kDa protein in T14 membrane vesicles was photolabeled by [3H]LTC4 and immunoprecipitation with MRP-specific monoclonal antibodies (mAbs) confirmed that this protein was MRP. LTC4 transport was inhibited by an MRP-specific mAb (QCRL-3) directed against an intracellular conformational epitope of MRP, but not by a mAb (QCRL-1) which recognizes a linear epitope. Photolabeling with [3H]LTC4 was also inhibitable by mAb QCRL-3 but not mAb QCRL-1. GSH did not inhibit LTC4 transport. However, the ability of alkylated GSH derivatives to inhibit transport increased markedly with the length of the alkyl group. S-Decylglutathione was a potent competitive inhibitor of [3H]LTC4 transport (K(i(app)) 116 nM), suggesting that the two compounds bind to the same, or closely related, site(s) on MRP. Chemotherapeutic agents including colchicine, doxorubicin, and daunorubicin were poor inhibitors of [3H]LTC4 transport. Taxol, VP-16, vincristine, and vinblastine were also poor inhibitors of LTC4 transport but inhibition by these compounds was enhanced by GSH. Uptake of [3H]vincristine into T14 membrane vesicles in the absence of GSH was low and not dependent on ATP. However, in the presence of GSH, ATP-dependent vincristine transport was observed. Levels of transport increased with concentrations of GSH up to 5 mM. The identification of an MRP-specific mAb that inhibits LTC4 transport and prevents photolabeling of MRP by LTC4, provides conclusive evidence of the ability of MRP to transport cysteinyl leukotrienes. Our studies also demonstrate that MRP is capable of mediating ATP-dependent transport of vincristine and that transport is GSH-dependent.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Adenosine Triphosphate, http://linkedlifedata.com/resource/pubmed/chemical/Antineoplastic Agents, http://linkedlifedata.com/resource/pubmed/chemical/Cations, Divalent, http://linkedlifedata.com/resource/pubmed/chemical/Glutathione, http://linkedlifedata.com/resource/pubmed/chemical/Leukotriene B4, http://linkedlifedata.com/resource/pubmed/chemical/Leukotriene C4, http://linkedlifedata.com/resource/pubmed/chemical/Membrane Proteins, http://linkedlifedata.com/resource/pubmed/chemical/P-Glycoprotein, http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Sucrose, http://linkedlifedata.com/resource/pubmed/chemical/Vinblastine, http://linkedlifedata.com/resource/pubmed/chemical/Vincristine
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
19
pubmed:volume
271
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9675-82
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:8621643-Adenosine Triphosphate, pubmed-meshheading:8621643-Antineoplastic Agents, pubmed-meshheading:8621643-Biological Transport, pubmed-meshheading:8621643-Carcinoma, Small Cell, pubmed-meshheading:8621643-Cations, Divalent, pubmed-meshheading:8621643-Cell Line, pubmed-meshheading:8621643-Cell Membrane, pubmed-meshheading:8621643-Glutathione, pubmed-meshheading:8621643-HeLa Cells, pubmed-meshheading:8621643-Humans, pubmed-meshheading:8621643-Kinetics, pubmed-meshheading:8621643-Leukotriene B4, pubmed-meshheading:8621643-Leukotriene C4, pubmed-meshheading:8621643-Lung Neoplasms, pubmed-meshheading:8621643-Membrane Proteins, pubmed-meshheading:8621643-Osmolar Concentration, pubmed-meshheading:8621643-P-Glycoprotein, pubmed-meshheading:8621643-Recombinant Proteins, pubmed-meshheading:8621643-Sucrose, pubmed-meshheading:8621643-Transfection, pubmed-meshheading:8621643-Tumor Cells, Cultured, pubmed-meshheading:8621643-Vinblastine, pubmed-meshheading:8621643-Vincristine
pubmed:year
1996
pubmed:articleTitle
Multidrug resistance protein (MRP)-mediated transport of leukotriene C4 and chemotherapeutic agents in membrane vesicles. Demonstration of glutathione-dependent vincristine transport.
pubmed:affiliation
Cancer Research Laboratories, Queen's University, Kingston, Ontario, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't