Alteration of Substrate Specificity by Mutations at the His61 Position in Predicted Transmembrane Domain 1 of Human MDR1/P-Glycoprotein
| العنوان: | Alteration of Substrate Specificity by Mutations at the His61 Position in Predicted Transmembrane Domain 1 of Human MDR1/P-Glycoprotein |
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| المؤلفون: | Kouichi Kino, Kazumitsu Ueda, Tohru Komano, Masaki Morishima, Yoshitomo Taguchi, Susan E. Kane |
| المصدر: | Biochemistry. 36:8883-8889 |
| بيانات النشر: | American Chemical Society (ACS), 1997. |
| سنة النشر: | 1997 |
| مصطلحات موضوعية: | Models, Molecular, DNA Mutational Analysis, Mutant, Cystic Fibrosis Transmembrane Conductance Regulator, Antineoplastic Agents, Vinblastine, Biochemistry, Substrate Specificity, Tumor Cells, Cultured, Side chain, Humans, Histidine, Rhodamine 123, ATP Binding Cassette Transporter, Subfamily B, Member 1, Gene, Ion channel, Etoposide, Fluorescent Dyes, P-glycoprotein, chemistry.chemical_classification, Antibiotics, Antineoplastic, Binding Sites, biology, Rhodamines, Fluoresceins, Antineoplastic Agents, Phytogenic, Protein Structure, Tertiary, Amino acid, Transmembrane domain, chemistry, Doxorubicin, Drug Resistance, Neoplasm, Mutagenesis, Site-Directed, biology.protein, Chloride channel, Colchicine |
| الوصف: | In CFTR, a member of the ABC superfamily and a chloride channel, amino acid substitutions in its transmembrane domains 1 and 6 (TM1, TM6) have been reported to modulate the anion selectivity or ion conductance of the ion channel. In P-glycoprotein, no amino acid substitution in TM1, but some in TM6, have been reported to modify the substrate specificity of this protein. In this work, we demonstrated the involvement of His61, which is in the middle of the predicted TM1, in the function of P-glycoprotein. His61 was replaced by all other amino acid residues, and each of the mutant cDNAs was introduced into drug-sensitive human carcinoma cells, KB3-1. The drug-resistance profile of cells stably expressing each mutated P-glycoprotein was investigated by comparing their relative resistance to vinblastine, colchicine, VP16, and adriamycin. The resistance to vinblastine was increased by replacing His61 by amino acids with smaller side chains, while it was lowered by replacing by amino acids with bulkier side chains. The reverse effect was observed for resistance to colchicine and VP16. The resistance to adriamycin was increased by replacing by amino acids with bulkier side chains except Lys or Arg, which have a basic side chain. We also showed that the replacement of His61 by Phe and Lys greatly impaired the efflux of calcein AM, while the replacement had no effect on the efflux of rhodamine 123. These results suggest that an amino acid residue at position 61 in TM1 is important in deciding the substrate specificity of P-glycoprotein. |
| تدمد: | 1520-4995 0006-2960 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f6cbbc23ca5f468663a930202e7a6fbf https://doi.org/10.1021/bi970553v |
| رقم الأكسشن: | edsair.doi.dedup.....f6cbbc23ca5f468663a930202e7a6fbf |
| قاعدة البيانات: | OpenAIRE |
Find this issue from the American Chemical Society | تدمد: | 15204995 00062960 |
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