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
発行・発表の年月 2000/10/13
形態種別 研究論文
標題 Identification of mammalian TOM22 as a subunit of the preprotein translocase of the mitochondrial outer membrane
執筆形態 その他
掲載誌名 Journal of Biological Chemistry
巻・号・頁 275(41),31996-32002頁
著者・共著者 Kazuko Saeki,Hiroyuki Suzuki,Makoto Tsuneoka,Maki Maeda,Ryo Iwamoto,Hidetoshi Hasuwa,Seiichiro Shida,Tsuyoshi Takahashi,Masao Sakaguchi,Toshiya Endo,Yoshiki Miura,Eisuke Mekada,Katsuyoshi Mihara
概要 A mitochondrial outer membrane protein of ~22 kDa (1C9-2) was purified from Vero cells assessing immuno-reactivity with a monoclonal antibody, and the cDNA was cloned based on the partial amino acid sequence of the trypsin-digested fragments. 1C9-2 had 19-20% sequence identity to fungal Tom22, a component of the preprotein translocase of the outer membrane (the TOM complex) with receptor and organizer functions. Despite such a low sequence identity, both shared a remarkable structural similarity in the hydrophobicity profile, membrane topology in the Ncyt-Cin orientation through a transmembrane domain in the middle of the molecule, and the abundant acidic amino acid residues in the N-terminal domain. The antibodies against 1C9-2 inhibited the import of a matrix-targeted preprotein into isolated mitochondria. Blue native polyacrylamide gel electrophoresis of digitonin-solubilized outer membranes revealed that 1C9-2 is firmly associated with TOM40 in the ~400-kDa complex, with a size and composition similar to those of the fungal TOM core complex. Furthermore, 1C9-2 complemented the defects of growth and mitochondrial protein import in Δtom22 yeast cells. Taken together, these results demonstrate that 1C9-2 is a functional homologue of fungal Tom22 and functions as a component of the TOM complex.
DOI 10.1074/jbc.M004794200
ISSN 0021-9258
PMID 10900208