高等植物の液胞の機能分化を支える膜蛋白質の変動

• Project/Area Number: 10219209
• Research Category: Grant-in-Aid for Scientific Research on Priority Areas
• Allocation Type: Single-year Grants
• Review Section: Biological Sciences
• Research Institution: Okazaki National Research Institutes
• Principal Investigator: 西村 幹夫 岡崎国立共同研究機構, 基礎生物学研究所, 教授 (80093061)
• Project Period (FY): 1998 – 2002
• Project Status: Completed (Fiscal Year 2002)
• Budget Amount: ¥36,000,000 (Direct Cost: ¥36,000,000); Fiscal Year 2002: ¥9,900,000 (Direct Cost: ¥9,900,000); Fiscal Year 2001: ¥10,800,000 (Direct Cost: ¥10,800,000); Fiscal Year 2000: ¥4,500,000 (Direct Cost: ¥4,500,000); Fiscal Year 1999: ¥5,300,000 (Direct Cost: ¥5,300,000); Fiscal Year 1998: ¥5,500,000 (Direct Cost: ¥5,500,000)
• Keywords: 高分子量前駆体 / PAC小胞 / 膜タンパク質 / PV72 / ゴルジ体 / タンパク質蓄積型液胞 / ツニカマイシン / ER / 液胞分化 / GFP / ゴルジ装置 / BY-2細胞 / 液胞輸送レセプター / 液胞 / オルガネラ分化 / 水チャネル / 形質転換植物 / 細胞内輸送 / 液胞プロセシング酵素 / 細胞死 / プロテイナーゼ

Research Abstract

私達は先に種子貯蔵タンパク質の前駆体を蓄積する新規な小胞(PAC小胞)が液胞への貯蔵タンパク質の輸送に働くことを明らかにしている。PV72はPAC小胞の主要な膜タンパク質として同定されたタイプ1型膜タンパク質である。PV72はCa^<2+>依存的に貯蔵タンパク質の1つである2S-アルブミンの前駆体と結合すること、また2S-アルブミン前駆体の液胞移行シグナルの局在するC末端と結合することが明らかとなった。PV72では種子の登熟中期に一過的に蓄積することから貯蔵タンパク質の合成に関与していることが示唆された。PV72とGFPの融合タンパク質はゴルジ体に局在していること、またPV72が複合型の糖鎖をもっていることから、PV72はゴルジ体を経由して運ばれていることが判明した。これらの結果から、PV72はPAC小胞とゴルジ体間をリサイクルしており、種子貯蔵タンパク質のレセプターとして働いていることが示唆された。

Research Products

• [Publications] Miwa Kuroyanagi: "Activation of Arabidopsis vacuolar processing enzyme by self-catalytic removal of an auto-inhibitory domain of the C-terminal propeptide"Plant Cell Physiol.. 43. 143-151 (2002)
• [Publications] Etsuko Watanabe: "Calcium-mediated association of a putative vacuolar sorting receptor PV72 with a propeptide of 2S albumin"J.Biol.Chem.. 277. 8708-8715 (2002)
• [Publications] Tomoo Shimada: "A vacuolar-sorting receptor on the membrane of the PAC vesicles that accumulate precursors of seed storage proteins"Plant Cell Physiol.. 43. 1086-1095 (2002)
• [Publications] Ryo Matsushima: "An endoplasmic reticulum-derived structure that is induced under stress conditions in Arabidopsis"Plant Physiol.. 130. 1807-1814 (2002)
• [Publications] Ryo Matsushima: "A novel ER-derived compartment, the ER body, selectively accumulates a b-glucosidase with an ER retention signal in Arabidopsis"Plant J. 33. 493-502 (2003)
• [Publications] Takao Minamikawa: "Degradation of ribulose-bisphosphate carboxylase by vacuolar enzymes of senescing French bean leaves : immunocytochemical and ultrastructural observations"Protoplasma. 218. 144-153 (2001)
• [Publications] Naoto Mitsuhashi: "A novel membrane protein that is of transported to protein storage vacuoles via precursor-accumulating vesicles"Plant Cell. 13. 2361-2372 (2001)
• [Publications] Yasuko Hayashi: "A proteinase-storing body that prepares for cell death or stresses in the epidermal cells of Arabidopsis"Plant Cell Physiol.. 42. 894-899 (2001)
• [Publications] Kenji Yamada: "A slow maturation of a cysteine protease with a granulin domain in the vacuoles of senescing Arabidopsis leaves"Plant Physiol.. 127. 1626-1634 (2001)
• [Publications] Naoto Mitsuhashi et.al: "Caracterization of Organelles in the Vacuolar-Sorting Pathway by Visualization with GFP in Tobacco BY-2 Cells"Plant Cell Physiol.. 41(9). 993-1001 (2000)
• [Publications] Yamada,K. et al.: "Multiple functional proteins are produced by cleaving Asn-G1n bonds of a single precursor protein by vacuolar processing enzyme."J.Boil.Chem.. 274. 2563-2570 (1999)
• [Publications] Hayashi,M. et al.: "Induction of precursor-accumulating vesicles by expression of chimeric genes consisting of pumpkin 2S albumin and phosphinothricin acetytransferase."Plant Cell Physiol.. 40. 263-272 (1999)
• [Publications] Koumoto,Y. et al.: "Chloroplast Cpn20 forms a tetrameric structure in Arabidopsis thaliana."Plant J.. 17. 467-477 (1999)
• [Publications] Hiraiwa,N., M.Nishimura and I.Hara-Nishimura: "Vacuolar processing enzyme is activated self-catalytically by sequential removal of the C-terminal and N-terminal propeptides."FEBS Lett.. 447. 213-216 (1999)
• [Publications] Kinoshita,T. et al.: "Vacuolar processing enzyme is up-regulated in the lytic vacuoles of vegetative tissues during senescence and under various stressed conditions."Plant J.. 19. 43-53 (1999)
• [Publications] Yamada,K.: "Multiple functional proteins are produced by cleaving Asn-Gln bonds of a single precursor by vacuolar processing enzyme." J.Biol.Chem.274. 2563-2570 (1999)
• [Publications] Hara-Nishimura,I.: "Transport of storage proteins to protein storage vacuoles is mediated by large precursor-accumulating vesicles." Plant Cell,. 10. 825-836 (1998)
• [Publications] Hara-Nishimura,I.: "Vacuolar processing enzyme in protein storage vacuoles and lytic vacuoles." J.Plant Physiol.152. 668-674 (1998)
• [Publications] Hiraiwa,N.: "Vacuolar processing enzyme is self-catalytically activated by a sequential removal of the C-terminal and N-terminal propeptides." FEBS Let.(in press).
• [Publications] Hayashi,M.: "Accumulation of a fusion protein containing 2S albumin induces novel vesicles in vegetative cells of Arabidopsis." Plant Cell Physiol.(in press).