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
言語種別 英語
発行・発表の年月 2010/05
形態種別 研究論文
査読 査読あり
標題 On the Impact of Precursor Unfolding during Protein Import into Chloroplasts
執筆形態 その他
掲載誌名 MOLECULAR PLANT
出版社・発行元 OXFORD UNIV PRESS
巻・号・頁 3(3),pp.499-508
著者・共著者 Maike Ruprecht,Tihana Bionda,Takehiro Sato,Maik S. Sommer,Toshiya Endo,Enrico Schleiff
概要 Protein translocation across membranes is a fundamental cellular process. The majority of the proteins of organelles such as mitochondria and chloroplasts is synthesized in the cytosol and subsequently imported in a post-translational manner. The precursor proteins have to be unfolded at least for translocation, but it has also been assumed that they are unfolded during transport to the organelle in the cytosol. Unfolding is governed by chaperones and the translocon itself. At the same time, chaperones provide the energy for the import process. The energetic properties of the chloroplast translocon were studied by import of the Ig-like module of the muscle protein titin fused to the transit peptide of the chloroplast targeted oxygen evolving complex subunit of 33 kDa (OE33). Our results suggest that p(OE33)titin is folded prior to import and that translocation is initiated by unfolding after having bound to the translocon at the chloroplast surface. Using a set of stabilizing and destabilizing mutants of titin previously analyzed by atomic force microscopy and as passenger for mitochondrial translocation, we studied the unfolding force provided by the chloroplast translocon. Based on these results, a model for translocation is discussed.
DOI 10.1093/mp/ssp116
ISSN 1674-2052