ABCB1 p.Asn91Gln
| Predicted by SNAP2: | A: N (57%), C: D (59%), D: N (61%), E: N (61%), F: N (57%), G: N (66%), H: N (57%), I: N (57%), K: N (53%), L: N (53%), M: N (53%), P: N (57%), Q: N (72%), R: N (53%), S: N (82%), T: N (82%), V: N (57%), W: D (75%), Y: N (53%), |
| Predicted by PROVEAN: | A: N, C: N, D: N, E: N, F: N, G: N, H: N, I: N, K: N, L: N, M: N, P: N, Q: N, R: N, S: N, T: N, V: N, W: D, Y: N, |
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[hide] A T3587G germ-line mutation of the MDR1 gene encod... Mol Cancer Ther. 2006 Apr;5(4):877-84. Mutoh K, Mitsuhashi J, Kimura Y, Tsukahara S, Ishikawa E, Sai K, Ozawa S, Sawada J, Ueda K, Katayama K, Sugimoto Y
A T3587G germ-line mutation of the MDR1 gene encodes a nonfunctional P-glycoprotein.
Mol Cancer Ther. 2006 Apr;5(4):877-84., [PMID:16648557]
Abstract [show]
The human multidrug resistance gene 1 (MDR1) encodes a plasma membrane P-glycoprotein (P-gp) that functions as an efflux pump for various structurally unrelated anticancer agents. We have identified two nonsynonymous germ-line mutations of the MDR1 gene, C3583T MDR1 and T3587G MDR1, in peripheral blood cell samples from Japanese cancer patients. Two patients carried the C3583T MDR1 allele that encodes H1195Y P-gp, whereas a further two carried T3587G MDR1 that encodes I1196S P-gp. Murine NIH3T3 cells were transfected with pCAL-MDR-IRES-ZEO constructs carrying either wild-type (WT), C3583T, or T3587G MDR1 cDNA and selected with zeocin. The resulting zeocin-resistant mixed populations of transfected cells were designated as 3T3/WT, 3T3/H1195Y, and 3T3/I1196S, respectively. The cell surface expression of I1196S P-gp in 3T3/I1196S cells could not be detected by fluorescence-activated cell sorting, although low expression of I1196S P-gp was found by Western blotting. H1195Y P-gp expression levels in 3T3/H1195Y cells were slightly lower than the corresponding WT P-gp levels in 3T3/WT cells. By immunoblotting analysis, both WT P-gp and H1195Y P-gp were detectable as a 145-kDa protein, whereas I1196S P-gp was visualized as a 140-kDa protein. 3T3/I1196S cells did not show any drug resistance unlike 3T3/H1195Y cells. Moreover, a vanadate-trap assay showed that the I1196S P-gp species lacks ATP-binding activity. Taken together, we conclude from these data that T3587G MDR1 expresses a nonfunctional P-gp and this is therefore the first description of such a germ-line mutation. We contend that the T3587G MDR1 mutation may affect the pharmacokinetics of MDR1-related anticancer agents in patients carrying this allele.
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No. Sentence Comment
196 The SDS-PAGE profile of I1196S P-gp is also very similar to the glycosylation-deficient P-gp that has the three amino acid substitutions, N91Q, N94Q, and N99Q (39).
X
ABCB1 p.Asn91Gln 16648557:196:138
status: NEW