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エンドウ トシヤ
ENDO TOSHIYA
遠藤 斗志也 所属 京都産業大学 生命科学部 先端生命科学科 職種 客員教授 |
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| 言語種別 | 英語 |
| 発行・発表の年月 | 2008/10 |
| 形態種別 | 研究論文 |
| 査読 | 査読あり |
| 標題 | Step-size analyses of the mitochondrial Hsp70 import motor reveal the Brownian ratchet in operation |
| 執筆形態 | その他 |
| 掲載誌名 | JOURNAL OF BIOLOGICAL CHEMISTRY |
| 出版社・発行元 | AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC |
| 巻・号・頁 | 283(40),pp.27325-27332 |
| 著者・共著者 | Koji Yamano,Mika Kuroyanagi-Hasegawa,Masatoshi Esaki,Mihoko Yokota,Toshiya Endo |
| 概要 | Newly synthesized mitochondrial precursor proteins have to become unfolded by the mitochondrial Hsp70 ( mtHsp70) import motor to cross the mitochondrial membranes. To assess the mechanism of unfolding of precursor proteins by mtHsp70, we designed a system to measure step sizes of the mtHsp70 import motor, which are distances at which the motor system moves along polypeptide chains during a single turnover of ATP. We made a series of fusion proteins consisting of a mitochondrial presequence containing the first mtHsp70 binding site, a spacer sequence containing an Hsp70 avoidance segment followed by the second mtHsp70 binding site, and different folded mature domains. Analyses of the dependence of the import rates of those fusion proteins on the lengths of Hsp70 avoidance segments allowed us to estimate the step sizes, which differ for different mature domains and different lengths of the spacers. These results suggest that the mtHsp70 import motor functions at least as a molecular Brownian ratchet to unfold mitochondrial precursor proteins. |
| DOI | 10.1074/jbc.M805249200 |
| ISSN | 0021-9258 |