蛋白質膜透過系を構成するSec因子の構造と膜透過の分子機構

• 研究課題/領域番号: 07458148
• 研究種目: 基盤研究(B)
• 配分区分: 補助金
• 応募区分: 一般
• 研究分野: 構造生物化学
• 研究機関: 東京大学
• 研究代表者: 徳田 元 東京大学, 分生細胞生物学研究所, 教授 (40125943)
• 研究期間 (年度): 1995 – 1996
• 研究課題ステータス: 完了 (1996年度)
• 配分額: 7,100千円 (直接経費: 7,100千円); 1996年度: 3,000千円 (直接経費: 3,000千円); 1995年度: 4,100千円 (直接経費: 4,100千円)
• キーワード: 蛋白質膜透過 / 膜蛋白質 / SecG / SecA / 合成致死 / 膜内配向性 / 膜トポロジー / 大腸菌

研究概要

4種のSec因子、SecA,SecY,SecE,SecGから効率の高い膜透過装置をプロテオリポソームに再構成する実験系を確立した。蛋白質膜透過系を構成する膜内在性因子SecGは、可溶性因子SecAと連携し、SecAが膜内に挿入する時SecGの膜内配向性が反転し、SecAが膜から脱離する時SecGの配向性が元に復帰することを明らかにした。SecAとSecGは膜透過反応時に相互作用すること、両因子の二重変異株は致死的になる場合があること、SecG欠損によってSecAの膜への挿入は低下すること、SecAの変異によってSecAの膜への挿入は低下すること、SecAの変異によってSecGの配向性反転も低下すること、などを明らかにした。

研究成果

• [文献書誌] Hanada,M.: "SecG plays a critical role in protein translocation in the absence of the proton motive force a well as at low temperature." FEBS Lett.381. 25-28 (1996)
  • 説明: 「研究成果報告書概要(和文)」より
• [文献書誌] Nishiyama,K.: "Inversion of the membrane topology of SecG coupled with SecA-dependent preprotein translocation." Cell. 85. 71-81 (1996)
  • 説明: 「研究成果報告書概要(和文)」より
• [文献書誌] Kontinen,V.P.: "Roles of the conserved cytoplasmic region and non-conserved carboxy-terminal region of SecE in E.coli protein translocase." J.Biochemistry. 119. 1124-1130 (1996)
  • 説明: 「研究成果報告書概要(和文)」より
• [文献書誌] Kontinen,V.P.: "The secG deletion mutation of Escherichia coli is suppressed by expression of a novel regulate gene of Bacillus subtilis." FEBS Lett.389. 281-284 (1996)
  • 説明: 「研究成果報告書概要(和文)」より
• [文献書誌] Hirano,M.: "The carboxyl-terminal region is essential for SecA dimerization." Biochem.Biophys.Res.Commun.229. 90-95 (1996)
  • 説明: 「研究成果報告書概要(和文)」より
• [文献書誌] Tokuda,H.: "Topology inversion of SecG,a membrane factor of E.coli protein translocase." Membrane Proteins. 183-190 (1997)
  • 説明: 「研究成果報告書概要(和文)」より
• [文献書誌] Kontinen,V.P.: "Overexpression of phosphatidylglycerophosphate synthase rcstores protein translocation in a secG deletion mutant of Escherichia coli at low temperature." FEBS Lett.364. 157-160 (1995)
  • 説明: 「研究成果報告書概要(和文)」より
• [文献書誌] Matsuyama,S.: "A novel pcriplasmic carrier protein involved in the sorting and transport of E.coli lipoproteins destined for the outer membrane." EMBOJ.14. 3365-3372 (1995)
  • 説明: 「研究成果報告書概要(和文)」より
• [文献書誌] Nishiyama,K.: "Prcferential interaction of SecG with SecE stabilizes an unstable SecE derivative in the Escherichia coli cytoplasmic membrane." Biochem.Biophys.Res.Commun.217. 217-223 (1995)
  • 説明: 「研究成果報告書概要(和文)」より
• [文献書誌] Akiyama,Y.: "FtsH (HПB) is an ATP-dependent pretcase sclectively acting on SecY and some ther membrane proteins." J.Biol.Chem.271. 31196-31201 (1996)
  • 説明: 「研究成果報告書概要(和文)」より
• [文献書誌] Tokuda,H.: "Protein traffic from the cytosol to the outer membrane of Escherichia coli." Protein targetting. (in press). (1997)
  • 説明: 「研究成果報告書概要(和文)」より
• [文献書誌] Kontinen V.P., and Tokuda, H.: "Overexpression of phosphatidylglycerophosphate synthase restores protein translocation in a secG deletion mutant of Escherichia coli at low temperature" FEBS Lett.364. 157-160 (1995)
  • 説明: 「研究成果報告書概要(欧文)」より
• [文献書誌] Matsuyama, S., Tajima, T., and Tokuda, H.: "A novel periplasmic carrier protein involved in the sorting and transport of E.coli lipoproteins destined for the outer membrane" EMBO J.14. 3365-3372 (1995)
  • 説明: 「研究成果報告書概要(欧文)」より
• [文献書誌] Nishiyama, K., and Tokuda, H.: "Preferential interaction of SecG with SecE stabilizes an unstable SecE derivative in the Escherichia coli cytoplasmic membrane" Biochem.Biophys.Res.Commun.217. 217-223 (1995)
  • 説明: 「研究成果報告書概要(欧文)」より
• [文献書誌] Hanada, M., Nishiyama, K., and Tokuda, H.: "SecG plays a critical role in protein translocation in the absence of the proton motive force as well as at low temperature" FEBS Lett.381. 25-28 (1996)
  • 説明: 「研究成果報告書概要(欧文)」より
• [文献書誌] Nishiyama, K., Suzuki, T., and Tokuda, H.: "Inversion of the membrane topology of SecG coupled with SecA-dependent preprotein translocation" Cell. 85. 71-81 (1996)
  • 説明: 「研究成果報告書概要(欧文)」より
• [文献書誌] Kontinen, V.P., Yamanaka, M., Nishiyama, K., and Tookuda, H.: "Roles of the conserved cytoplasmic region and non-conserved carboxyterminal region of SecE in E.coli protein translocase" J.Biochemistry. 119. 1124-1130 (1996)
  • 説明: 「研究成果報告書概要(欧文)」より
• [文献書誌] Kontinen, V.P., Helander, I.M., and Tokuda, H.: "The secG deletion mutation of Escherichia coli is suppressed by expression of a novel regulatory gene of Bacillus subtilis" FEBS Lett.389. 281-284 (1996)
  • 説明: 「研究成果報告書概要(欧文)」より
• [文献書誌] Hirano, M., Matsuyama, S., and Tokuda, H.: "The carboxyl-terminal region is essential for SecA dimerization" Biochem.Biophys.Res.Commun.229. 90-95 (1996)
  • 説明: 「研究成果報告書概要(欧文)」より
• [文献書誌] Akiyama, Y., Kihara, A., Tokuda, H., and Ito, K.: "FtsH (HflB) is an ATP-dependent protease selectively acting on SecY and some other membrane proteins." J.Biol.Chem.271. 31196-31201 (1996)
  • 説明: 「研究成果報告書概要(欧文)」より
• [文献書誌] Tokuda, H.: "Topology inversion of SecG,a membrane factor of E.coli protein translocase" Membrane Proteins : "Structure, function and expression control" (ed.N.Hamasaki and K.Mihara, Kyusyu University Press/Karger Medical and Scientific Publishers). 183-190 (1997)
  • 説明: 「研究成果報告書概要(欧文)」より
• [文献書誌] Tokuda, H., and Matsuyama, S.: "Protein traffic from the cytosol to the outer membrane of Escherichia coli" "Protein targetting" (ed.D.Protein Phoenix, Portland Press). (in press). (1997)
  • 説明: 「研究成果報告書概要(欧文)」より
• [文献書誌] Hanada,M.: "SecG plays a critical role in protein translocation in the absence of the proton motive force as well as at low temperature." FEBS Lett.381. 25-28 (1996)
• [文献書誌] Nishiyama,K.: "Inversion of the membrane topology of SecG coupled with SecA-dependent preprotein translocation." Cell. 85. 71-81 (1996)
• [文献書誌] Kontinen,V.P.: "Roles of the conserved cytoplasmic region and non-conserved carboxy-terminal region of SecE in E.coli protein translocase." J.Biochemistry. 119. 1124-1130 (1996)
• [文献書誌] Kontinen,V.P.: "The secG deletion mutation of Escherichia coli is suppressed by expression of a novel regulatory gene of Bacillus subtilis." FEBS Lett.389. 281-284 (1996)
• [文献書誌] Hirano,M.: "The carboxyl-terminal region is essential for SecA dimerization." Biochem.Biophys.Res.Commun.229. 90-95 (1996)
• [文献書誌] Tokuda,H.: "Topology inversion of SecG,a membrane factor of E.coli protein translocase." Kyushu University Press.(in press). (1997)
• [文献書誌] Kontinen,V.P.: "Overexpression of phosphatidylglycerophosphate synthase restores protein translocation in a secG deletion mutant of Escherichia coli at temperature." FEBS Lett.364. 157-160 (1995)
• [文献書誌] Matsuyama,S.: "A novel periplasmic carmier protein involved in the sorting and transport of E.coli Iipoproteins destined for theouter membrane." EMBOJ.14. 3365-3372 (1995)
• [文献書誌] Nishiyama,K.: "Preferential interaction of SecG with SecE stabilizes an unstable SecE derivative in the Escherichia coli cytoplasmic membrane." Biochem.Biophys.Res.Commun.217. 217-223 (1995)
• [文献書誌] Nishiyama,K.: "Inversion of the membrane topology of SecG coupled with SecA-dependent preprotein translocation." Cell. (in press). (1996)
• [文献書誌] Hanada,M.: "SecG plays a critical role in protein translocation in the absence of the proton motive force as well as at low temperature." FEBS Lett.(in press). (1996)