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BioAssay: AID 681905

TP_TRANSPORTER: inhibition of MTX uptake (MTX: 20 uM, cAMP: 300 uM) in membrane vesicles from MRP4-expressing Sf9 cells

Human MRP4 (ABCC4, MOAT-B) is a lipophilic anion transporter that is able to confer resistance to nucleotide analogues and methotrexate (MTX). We previously investigated the implications of the ability of MRP4 to confer resistance to nucleotide analogues and determined that the pump is competent in the MgATP-energized transport of cyclic nucleotides and estradiol 17beta-D-glucuronide. Here we more ..
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 Tested Compounds
 Tested Compounds
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Unspecified(1)
 
 
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 Related BioAssays
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AID: 681905
Data Source: ChEMBL (839044)
Depositor Category: Other
BioAssay Version:
Deposit Date: 2013-05-16
Modify Date: 2013-11-17

Data Table ( Complete ):           All
Target
Sequence: RecName: Full=Multidrug resistance-associated protein 4; AltName: Full=ATP-binding cassette sub-family C member 4; AltName: Full=MRP/cMOAT-related ABC transporter; AltName: Full=Multi-specific organic anion transporter B; Short=MOAT-B
Description ..   
Protein Family: ATP-binding cassette domain 2 of multidrug resistance-associated protein
Comment ..   

Gene:ABCC4     Related Protein 3D Structures     More BioActivity Data..
Tested Compound:
Description:
Title: Analysis of methotrexate and folate transport by multidrug resistance protein 4 (ABCC4): MRP4 is a component of the methotrexate efflux system.

Abstract: Human MRP4 (ABCC4, MOAT-B) is a lipophilic anion transporter that is able to confer resistance to nucleotide analogues and methotrexate (MTX). We previously investigated the implications of the ability of MRP4 to confer resistance to nucleotide analogues and determined that the pump is competent in the MgATP-energized transport of cyclic nucleotides and estradiol 17beta-D-glucuronide. Here we examine the potential role of MRP4 in conferring resistance to MTX and related processes by determining the selectivity of the transporter for MTX, MTX polyglutamates, and physiological folates. In so doing, it is shown that MRP4 is active in the transport of MTX as well as the physiological folates folic acid (FA) and N(5)-formyltetrahydrofolic acid (leucovorin). MTX, FA, and leucovorin are subject to high capacity [V(max(MTX)), 0.24 +/- 0.05 nmol/mg/min; V(max (FA)), 0.68 +/- 0.14 nmol/mg/min; V(max(leucovorin)), 1.95 +/- 0.18 nmol/mg/min], low affinity [K(m(MTX)), 0.22 +/- 0.01 mM; K(m(FA)), 0.17 +/- 0.02 mM; K(m (leucovorin)), 0.64 +/- 0.23 mM] transport by MRP4. In addition, as would be expected were MRP4 a component of the MTX efflux system, its capacity to transport this agent is abrogated by the addition of a single glutamyl residue. It is also shown that glutamylation similarly affects the ability of MRP2 to transport MTX. On the basis of these transport properties, it is concluded that the efflux system for MTX includes MRP2 and MRP4, in addition to MRP1 and MRP3, and that MRP4 represents a common efflux system for both MTX and certain nucleotide analogues.
Categorized Comment
ChEMBL Assay Type: Functional

ChEMBL Assay Data Source: TP-search Transporter Database

ChEMBL Assay Test Type: In vitro

ChEMBL Assay Cell Type: Sf9

ChEMBL Assay Subcellular Fraction: membrane vesicle

ChEMBL Target ID: 104069

ChEMBL Target Type: Target is a single protein chain

Result Definitions
TIDNameDescriptionHistogramTypeUnit
OutcomeThe BioAssay activity outcomeOutcome
1Activity activity commentActivity activity commentString
2Activity standard flagActivity standard flagInteger
3Activity qualifierActivity qualifierString
4Activity published valueActivity published valueFloat%
5Activity standard valueActivity standard valueFloat%

Data Table (Concise)
Classification
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