1990 Fiscal Year Annual Research Report

シナプス小胞と原形質膜との融合過程における低分子量GTP結合蛋白質の役割

Research Project

Project/Area Number	02241208
Research Institution	Kobe University
Principal Investigator	菊池章神戸大学, 医学部, 助手 (10204827)
Keywords	低分子量GTP結合蛋白質 / <smg>___ー p25A / GDP解離抑制蛋白質 / シナプス / トランスロケ-ション
Research Abstract	昨年度までに私共は低分子量G蛋白質の1つである<smg>___ー p25Aを均一に精製し、そのcDNAを単離し、さらに<smg>___ー p25AのmRNAが大脳、小脳や副腎髄質などの神経組織に大量に発現していることを明らかにした。本年度はまず、<smg>___ー p25Aの神経組織における細胞内分布を生化学的解析と免疫電顕的解析により検討した。その結果、<smg>___ー p25Aは大脳ではシナプスに最も大量に存在し、シナプス内では主としてシナプス小胞と前シナプス膜に、一部シナプス可溶性画分にも存在するが、後シナプス膜には存在しないことが明らかになった。一方、組織化学的解析により、<smg>___ー p25Aはシナプス以外にも外分泌細胞や内分泌細胞に存在することが明らかとなった。したがって、<smg>___ー p25Aは分泌反応に重要な役割を果していることが示唆された。続いて、私共は<smg>___ー p25AのGDP/GTP交換反応を抑制するGDP解離抑制蛋白質(GDI)を均一蛋白質にまで精製し、そのcDNAを単離して、全一次構造を決定した。<smg>___ー p25AGDIは447個のアミノ酸から成る分子量50,565の蛋白質であった。また、私共は<smg>___ー p25AはGDP結合型でもGTP結合型でもシナプス小胞やシナプス膜に結合することを見出した。さらに、私共は<smg>___ー p25A GDIがGDP結合型<smg>___ー p25Aのシナプス小胞やシナプス膜への結合を抑制することと、一度シナプス小胞やシナプス膜に結合したGDP結合型<smg>___ー p25Aのそれらからの解離を促進することを明らかにした。しかし、<smg>___ー p25A GDIはGTP結合型<smg>___ー p25Aのシナプス小胞やシナプス膜への結合には作用しなかった。したがって、シナプスにおいて<smg>___ー p25Aは<smg>___ー p25Aのトランスロケ-ションを制御していると考えられる。ある種の低分子量G蛋白質が小胞と細胞膜の融合に関与している可能性が示唆されているので、<smg>___ー p25A GDIー<smg>___ー p25A系はシナプスにおいてシナプス小胞とシナプス膜との融合過程に関与している可能性が強いと考えられる。以上の結果を得たことにより、本年度の研究計画はほぼ達成できたと考えている。

Research Products

(12 results)

All Other

All Publications (12 results)

[Publications] Sasaki,T.: "Purification and characterization from bovine brain cytosol of a protein that inhibits the dissociation of GDP from and the subsequent binding of GTP to smg p25A,a ras p21ーlike GTPーbinding protein." J.Biol.Chem.265. 2333-2337 (1990)
[Publications] Hata,Y.: "Inhibition of the ras p21 GTPaseーactivating proteinーstimulated GTPase activity of cーHaーras p21 by smg p21 having the same putative effector domain as ras p21s." J.Biol.Chem.265. 7104-7107 (1990)
[Publications] Ueda,T.: "Purification and characterization from bovine brain cytosol of a novel regulatory protein inhibiting the dissociation of GDP from and the subsequent binding of GTP to rhoB p20,a ras p21ーlike GTPーbinding protein." J.Biol.Chem.265. 9373-9380 (1990)
[Publications] Mizoguchi,A.: "Localization and subcellular distribution of smg p25A,a ras p21ーlike GTPーbinding protein,in rat brain." J.Biol.Chem.265. 11872-11879 (1990)
[Publications] Araki,S.: "Regulation of reversible binding of smg p25A,a ras p21ーlike GTPーbinding protein,to synaptic plasma membranes and vesicles by its specific regulatory protein,GDP dissociation inhibitor." J.Biol.Chem.265. 13007-13015 (1990)
[Publications] Kim,S.: "Tissue and subcellular distributions of the smgー21/rap1/Krevー1 proteins which are partly distinct from those of cーras p21s." Mol.Cell.Biol.10. 2645-2652 (1990)
[Publications] Matsui,Y.: "Molecular cloning and characterization of a novel type of regulatory protein (GDI) for smg p25A,a ras p21ーlike GTPーbinding protein." Mol.Cell.Biol.10. 4116-4122 (1990)
[Publications] Hoshijima,M.: "Purification and characterization from bovine brain membranes of a GTPーbinding protein with a Mr of 21,000 ADPーribosylated by an ADPーribosyl transferase contaminated in botulinum toxin type C1ーidentification as the rhoA gene product." Mol.Brain Res.7. 9-16 (1990)
[Publications] Yamamoto,J.: "A GTPaseーactivating protein for rhoB p20,a ras p21ーlike GTPーbinding proteinーpartial purification,characterization and subcellular distribution in rat brain." Mol.Brain Res.7. 105-111 (1990)
[Publications] Fukumoto,Y.: "Molecular cloning and characterization of a novel type of regulatory protein (GDI) for the rho proteins,ras p21ーlike small GTPーbinding proteins." Oncogene. 5. 1321-1328 (1990)
[Publications] Matsui,Y.: "Molecular cloning of smg p21B and identification of smg p21 purified from bovine brain and human platelets as smg p21B." Biochem.Biophys.Res.Commun.166. 1010-1016 (1990)
[Publications] Fujioka,H.: "A small GTPーbinding protein (G protein) recognized by smg p25A GDP dissociation inhibitor (GDI) in human platelet membranes and GDI for this small G protein in human platelet cytosol." Biochem.Biophys.Res.Commun.1244. 168-1252 (1990)

1990 Fiscal Year Annual Research Report

シナプス小胞と原形質膜との融合過程における低分子量GTP結合蛋白質の役割

Principal Investigator

菊池 章 神戸大学, 医学部, 助手 (10204827)

Research Products

[Publications] Sasaki,T.: "Purification and characterization from bovine brain cytosol of a protein that inhibits the dissociation of GDP from and the subsequent binding of GTP to smg p25A,a ras p21ーlike GTPーbinding protein." J.Biol.Chem.265. 2333-2337 (1990)

[Publications] Hata,Y.: "Inhibition of the ras p21 GTPaseーactivating proteinーstimulated GTPase activity of cーHaーras p21 by smg p21 having the same putative effector domain as ras p21s." J.Biol.Chem.265. 7104-7107 (1990)

[Publications] Ueda,T.: "Purification and characterization from bovine brain cytosol of a novel regulatory protein inhibiting the dissociation of GDP from and the subsequent binding of GTP to rhoB p20,a ras p21ーlike GTPーbinding protein." J.Biol.Chem.265. 9373-9380 (1990)

[Publications] Mizoguchi,A.: "Localization and subcellular distribution of smg p25A,a ras p21ーlike GTPーbinding protein,in rat brain." J.Biol.Chem.265. 11872-11879 (1990)

[Publications] Araki,S.: "Regulation of reversible binding of smg p25A,a ras p21ーlike GTPーbinding protein,to synaptic plasma membranes and vesicles by its specific regulatory protein,GDP dissociation inhibitor." J.Biol.Chem.265. 13007-13015 (1990)

[Publications] Kim,S.: "Tissue and subcellular distributions of the smgー21/rap1/Krevー1 proteins which are partly distinct from those of cーras p21s." Mol.Cell.Biol.10. 2645-2652 (1990)

[Publications] Matsui,Y.: "Molecular cloning and characterization of a novel type of regulatory protein (GDI) for smg p25A,a ras p21ーlike GTPーbinding protein." Mol.Cell.Biol.10. 4116-4122 (1990)

[Publications] Yamamoto,J.: "A GTPaseーactivating protein for rhoB p20,a ras p21ーlike GTPーbinding proteinーpartial purification,characterization and subcellular distribution in rat brain." Mol.Brain Res.7. 105-111 (1990)

[Publications] Fukumoto,Y.: "Molecular cloning and characterization of a novel type of regulatory protein (GDI) for the rho proteins,ras p21ーlike small GTPーbinding proteins." Oncogene. 5. 1321-1328 (1990)

[Publications] Matsui,Y.: "Molecular cloning of smg p21B and identification of smg p21 purified from bovine brain and human platelets as smg p21B." Biochem.Biophys.Res.Commun.166. 1010-1016 (1990)

[Publications] Fujioka,H.: "A small GTPーbinding protein (G protein) recognized by smg p25A GDP dissociation inhibitor (GDI) in human platelet membranes and GDI for this small G protein in human platelet cytosol." Biochem.Biophys.Res.Commun.1244. 168-1252 (1990)

菊池章神戸大学, 医学部, 助手 (10204827)