ABCC1 p.Pro1150Val
| Predicted by SNAP2: | A: N (57%), C: N (57%), D: D (66%), E: D (66%), F: D (59%), G: D (63%), H: D (63%), I: D (63%), K: D (66%), L: D (59%), M: D (59%), N: D (59%), Q: D (59%), R: D (63%), S: N (57%), T: D (59%), V: D (63%), W: D (71%), Y: D (59%), |
| Predicted by PROVEAN: | A: D, C: D, D: D, E: D, F: D, G: D, H: D, I: D, K: D, L: D, M: D, N: D, Q: D, R: D, S: D, T: D, V: D, W: D, Y: D, |
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[hide] Role of proline 1150 in functional interactions be... Biochem Pharmacol. 2008 Apr 15;75(8):1659-69. Epub 2008 Feb 5. Letourneau IJ, Nakajima A, Deeley RG, Cole SP
Role of proline 1150 in functional interactions between the membrane spanning domains and nucleotide binding domains of the MRP1 (ABCC1) transporter.
Biochem Pharmacol. 2008 Apr 15;75(8):1659-69. Epub 2008 Feb 5., 2008-04-15 [PMID:18336795]
Abstract [show]
The ATP-binding cassette multidrug resistance protein 1 (MRP1) mediates ATP-dependent cellular efflux of drugs and organic anions. We previously described a mutant, MRP1-Pro1150Ala, which exhibits selectively increased estradiol glucuronide (E217betaG) and methotrexate transport as well as altered interactions with ATP. We have now further explored the functional importance of MRP1-Pro1150 at the interface of transmembrane helix 15 and cytoplasmic loop 7 (CL7) by replacing it with Gly, Ile, Leu and Val. All four mutants exhibited a phenotype similar to MRP1-Pro1150Ala with respect to organic anion transport and [gamma32P]8N3ATP photolabeling. They also displayed very low levels of substrate-independent vanadate-induced trapping of [alpha32P]8N3ADP. To better understand the relationship between the altered nucleotide interactions and transport activity of these mutants, [alpha32P]8N3ADP trapping experiments were performed under different conditions. Unlike leukotriene C4, E217betaG decreased [alpha32P]8N3ADP trapping by both wild-type and mutant MRP1. [alpha32P]8N3ADP trapping by MRP1-Pro1150Ala could be increased by using Ni2+ instead of Mg2+, and by decreasing temperature; however, the transport properties of the mutant remained unchanged. We conclude that the reduced [alpha32P]8N3ADP trapping associated with loss of Pro1150, or the presence of E217betaG, is due to enhanced ADP release following ATP hydrolysis rather than a reduction in ATP hydrolysis itself. We hypothesize that loss of Pro1150 alters the role of CL7 as a coupling helix that mediates signaling between the nucleotide binding domains and some substrate binding sites in the membrane spanning domains of MRP1.
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No. Sentence Comment
52 Mutagenesis was performed according to the manufacturer`s instructions with the following sense primers (the substituted nucleotides causing the mutation are underlined; silent nucleotide substitutions added to introduce or disrupt a restriction site are in bold; other nucleotide substitutions are in lowercase typeface; and diagnostic restriction enzymes are indicated in parentheses): MRP1-Pro1150Gly (50 -G TCG GTC AGC CGG TCg GGG GTC TAT TCC C-30 ) (BsrFI), MRP1-Pro1150Ile (50 -C AGC CGC TCC ATC GTC TAC TCC CAT TTC AAC-30 ) (AccI), MRP1- Pro1150Leu (50 -CG GTC AGC CGG TCC CTC GTC TAC TCC CAT TTC-30 ) (AccI) and MRP1-Pro1150Val (50 -CG GTC AGC CGG TCC GTG GTC TAT TCC C-30 ) (RsrII).
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ABCC1 p.Pro1150Val 18336795:52:625
status: NEW109 Levels of [3 H]LTC4 labeling of the Pro1150Gly, Pro1150Ile, Pro1150Leu and Pro1150Val mutants were also comparable to wild-type MRP1 (Fig. 3A).
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ABCC1 p.Pro1150Val 18336795:109:75
status: NEW147 Under these conditions, the Pro1150Gly, Pro1150Ile and Pro1150Leu mutants exhibited similar levels of [a32 P]8N3ADP trapping (50-70% reduction) (Fig. 5B), while trapping by the Pro1150Val mutant was only slightly reduced (20%) relative to wild-type MRP1 (Fig. 5B).
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ABCC1 p.Pro1150Val 18336795:147:177
status: NEW221 Although none of the amino acids could replace Pro1150 with respect to the substrate specificity of MRP1, it is interesting that MRP1-Pro1150Val exhibited a substantially smaller decrease in vanadate-induced [a32 P]8N3ADP trapping than the other mutants.
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ABCC1 p.Pro1150Val 18336795:221:134
status: NEW[hide] Structural and functional properties of human mult... Curr Med Chem. 2011;18(3):439-81. He SM, Li R, Kanwar JR, Zhou SF
Structural and functional properties of human multidrug resistance protein 1 (MRP1/ABCC1).
Curr Med Chem. 2011;18(3):439-81., [PMID:21143116]
Abstract [show]
Multidrug ABC transporters such as P-glycoprotein (P-gp/MDR1/ABCB1) and multidrug resistance protein 1 (MRP1/ABCC1) play an important role in the extrusion of drugs from the cell and their overexpression can be a cause of failure of anticancer and antimicrobial chemotherapy. Recently, the mouse P-gp/Abcb1a structure has been determined and this has significantly enhanced our understanding of the structure-activity relationship (SAR) of mammalian ABC transporters. This paper highlights our current knowledge on the structural and functional properties and the SAR of human MRP1/ABCC1. Although the crystal structure of MRP1/ABCC1 has yet to be resolved, the current topological model of MRP1/ABCC1 contains two transmembrane domains (TMD1 and TMD2) each followed by a nucleotide binding domain (NBD) plus a third NH2-terminal TMD0. MRP1/ABCC1 is expressed in the liver, kidney, intestine, brain and other tissues. MRP1/ABCC1 transports a structurally diverse array of important endogenous substances (e.g. leukotrienes and estrogen conjugates) and xenobiotics and their metabolites, including various conjugates, anticancer drugs, heavy metals, organic anions and lipids. Cells that highly express MRP1/ABCC1 confer resistance to a variety of natural product anticancer drugs such as vinca alkaloids (e.g. vincristine), anthracyclines (e.g. etoposide) and epipodophyllotoxins (e.g. doxorubicin and mitoxantrone). MRP1/ABCC1 is associated with tumor resistance which is often caused by an increased efflux and decreased intracellular accumulation of natural product anticancer drugs and other anticancer agents. However, most compounds that efficiently reverse P-gp/ABCB1-mediated multidrug resistance have only low affinity for MRP1/ABCC1 and there are only a few effective and relatively specific MRP1/ABCC1 inhibitors available. A number of site-directed mutagenesis studies, biophysical and photolabeling studies, SAR and QSAR, molecular docking and homology modeling studies have documented the role of multiple residues in determining the substrate specificity and inhibitor selectivity of MRP1/ABCC1. Most of these residues are located in the TMs of TMD1 and TMD2, in particular TMs 4, 6, 7, 8, 10, 11, 14, 16, and 17, or in close proximity to the membrane/cytosol interface of MRP1/ABCC1. The exact transporting mechanism of MRP1/ABCC1 is unclear. MRP1/ABCC1 and other multidrug transporters are front-line mediators of drug resistance in cancers and represent important therapeutic targets in future chemotherapy. The crystal structure of human MRP1/ABCC1 is expected to be resolved in the near future and this will provide an insight into the SAR of MRP1/ABCC1 and allow for rational design of anticancer drugs and potent and selective MRP1/ABCC1 inhibitors.
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No. Sentence Comment
758 The Pro1150Gly, Pro1150Ile, Pro1150Leu and Pro1150Val mutants exhibited a phenotype similar to the Pro1150Ala mutant with respect to organic anion transport and [ 32 P]8N3ATP photolabeling [347].
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ABCC1 p.Pro1150Val 21143116:758:43
status: NEW