1995 Fiscal Year Annual Research Report

神経伝達物質の放出機構におけるRab3A低分子量G蛋白質系の機能と作用機構

Research Project

Project/Area Number	07279225
Research Institution	Osaka University
Principal Investigator	佐々木卓也大阪大学, 医学部, 助手 (40241278)
Co-Investigator(Kenkyū-buntansha)	高井義美大阪大学, 医学部, 教授 (60093514)
Keywords	Rab3A / 低分子量G蛋白質 / 神経伝達物質 / Rabphilin-3A / C2様領域 / Ca^<2+> / Ca^<2+>センサー / RabGDI
Research Abstract	私共の研究室では、Rab3A低分子量G蛋白質とその関連蛋白質による神経伝達物質の放出の制御について解析を続けている。私共は、Rab3Aの標的蛋白質Rabphilin-3Aを見い出しているが、本年度の本研究で、Rabphilin-3Aが細胞内で神経伝達物質の放出に実際に働いていることを証明した。すなわち、私共は、Rabphilin-3Aとその変異体のリコンビナント蛋白質をヤリイカの巨大シナプスにマイクロインジェクションすることによって、Rabphilin-3Aが神経伝達物質の放出を制御していることを明らかにした。さらに、私共は、Rabphilin-3Aとそのアンチセンスや変異体の遺伝子を、ヒト成長ホルモン(GH)の遺伝子と共に、クロマフィン細胞やPC12細胞に強制発現させることによって、Rabphilin-3AがCa^<2+>依存性のGHの分泌を制御することを明らかにした。神経伝達物質の放出にはプレシナプス内のCa^<2+>の流入が必要であるが、私共は、Rabphilin-3AのC2様領域が実際にCa^<2+>と結合することから、Rabphilin-3AがCa^<2+>センサーとなって神経伝達物質の放出を制御していると考えている。一方、私共は、すでに、Rab3Aの活性制御蛋白質としてRab GDIを見い出しているが、本年度の本研究で、新たに、Rab3Aを活性化するRab3A GETと、Rab3Aを不活化するRab3A GAPの精製に世界に先がけて成功した。このように、本年度の本研究は予想以上に進展し、当初の目的はほぼ完全に達成することができた。

Research Products

(12 results)

All Other

All Publications (12 results)

[Publications] Kuribara,H.: "Synergist activation of rat brain phospholipase D by ADP-ribosylation factor and rhoA p21, and its inhibition by clostridium botulinum C3 exoenzyme." J. Biol. Chem.270. 25667-25671 (1995)
[Publications] Takaishi,K.: "Translocation of activated Rho from the cytopiasm to membrane ruffling area, cell-cell adhesion sites and cleavage furrows." Oncogene. 11. 39-48 (1995)
[Publications] Orita,S.: "Doc2: a novel brain protein havig two repeated C2-like domains." Biochem. Biophys. Res. Commun.206. 439-448 (1995)
[Publications] Araki,K.: "purification and characterization of Rab GDIβ from rat brain." Biochem. Biophys. Res. Commun.211. 296-305 (1995)
[Publications] Takahashi,K.: "Heterotetramer formation of prenylated Rab3A with two Rabphilin-3A molecules." Biochem. Biophys. Res. Commun.217. 979-986 (1995)
[Publications] Regazzi,R.: "Prenylcysteine analogs mimicking the C-terminus of GTP-binding proteins stimulate exocytosis from Permeabilized HIT-T15 cells- compatrson with the effect of Rab3AL peptide." Biochim. Biophys. Acta. 1268. 269-278 (1995)
[Publications] Takai,Y.: "Rho as a regulator of the cytoskeleton." Trends in Biochemical Sciences. 20. 227-231 (1995)
[Publications] Orita,S.: "Doc2 enhances Ca^<2+>-dependent exocytosis from PC12 cells." J. Biol. Chem.(in press).
[Publications] Fujita,Y.: "Phosphorylation of Munc-18/n-Secl/rbSec1 by protein kinase C- Its implication in regulating the interaction of Munc-18/n-Secl/rbSecl with Syntaxin." J. Biol. Chem.(in press).
[Publications] Matsuda,S.: "A membrane-associated GDP/GTP exchange protein specific for Rho small GTP-binding protein-partial purification and Characterization from rat brain." Oncogene. (in press).
[Publications] Taniguchi,T.: "Cholecystokinin-B/gastrin receptors mediate rapid formation of actin stress fibers." Oncogene. (in press).
[Publications] Komuro,R.: "Involvement of rabphilin-3A in Ca^<2+>-dependent exocytosis from PC12 cells." Biochem. Biophys. Res. Commun.(in press).

1995 Fiscal Year Annual Research Report

神経伝達物質の放出機構におけるRab3A低分子量G蛋白質系の機能と作用機構

Principal Investigator

佐々木 卓也 大阪大学, 医学部, 助手 (40241278)

Research Products

[Publications] Kuribara,H.: "Synergist activation of rat brain phospholipase D by ADP-ribosylation factor and rhoA p21, and its inhibition by clostridium botulinum C3 exoenzyme." J. Biol. Chem.270. 25667-25671 (1995)

[Publications] Takaishi,K.: "Translocation of activated Rho from the cytopiasm to membrane ruffling area, cell-cell adhesion sites and cleavage furrows." Oncogene. 11. 39-48 (1995)

[Publications] Orita,S.: "Doc2: a novel brain protein havig two repeated C2-like domains." Biochem. Biophys. Res. Commun.206. 439-448 (1995)

[Publications] Araki,K.: "purification and characterization of Rab GDIβ from rat brain." Biochem. Biophys. Res. Commun.211. 296-305 (1995)

[Publications] Takahashi,K.: "Heterotetramer formation of prenylated Rab3A with two Rabphilin-3A molecules." Biochem. Biophys. Res. Commun.217. 979-986 (1995)

[Publications] Regazzi,R.: "Prenylcysteine analogs mimicking the C-terminus of GTP-binding proteins stimulate exocytosis from Permeabilized HIT-T15 cells- compatrson with the effect of Rab3AL peptide." Biochim. Biophys. Acta. 1268. 269-278 (1995)

[Publications] Takai,Y.: "Rho as a regulator of the cytoskeleton." Trends in Biochemical Sciences. 20. 227-231 (1995)

[Publications] Orita,S.: "Doc2 enhances Ca^<2+>-dependent exocytosis from PC12 cells." J. Biol. Chem.(in press).

[Publications] Fujita,Y.: "Phosphorylation of Munc-18/n-Secl/rbSec1 by protein kinase C- Its implication in regulating the interaction of Munc-18/n-Secl/rbSecl with Syntaxin." J. Biol. Chem.(in press).

[Publications] Matsuda,S.: "A membrane-associated GDP/GTP exchange protein specific for Rho small GTP-binding protein-partial purification and Characterization from rat brain." Oncogene. (in press).

[Publications] Taniguchi,T.: "Cholecystokinin-B/gastrin receptors mediate rapid formation of actin stress fibers." Oncogene. (in press).

[Publications] Komuro,R.: "Involvement of rabphilin-3A in Ca^<2+>-dependent exocytosis from PC12 cells." Biochem. Biophys. Res. Commun.(in press).

佐々木卓也大阪大学, 医学部, 助手 (40241278)