メンブレントラフィックによる調節性分泌の制御機構

• Project/Area Number: 15079201
• Research Category: Grant-in-Aid for Scientific Research on Priority Areas
• Allocation Type: Single-year Grants
• Review Section: Biological Sciences
• Research Institution: Gunma University
• Principal Investigator: 泉 哲郎 Gunma University, 生体調節研究所, 教授 (00212952)
• Project Period (FY): 2003 – 2007
• Project Status: Completed (Fiscal Year 2007)
• Budget Amount: ¥106,400,000 (Direct Cost: ¥106,400,000); Fiscal Year 2007: ¥19,600,000 (Direct Cost: ¥19,600,000); Fiscal Year 2006: ¥19,600,000 (Direct Cost: ¥19,600,000); Fiscal Year 2005: ¥19,600,000 (Direct Cost: ¥19,600,000); Fiscal Year 2004: ¥23,800,000 (Direct Cost: ¥23,800,000); Fiscal Year 2003: ¥23,800,000 (Direct Cost: ¥23,800,000)
• Keywords: 調節性分泌 / 分泌顆粒 / インスリン分泌 / SNARE蛋白質 / Rab蛋白質

Research Abstract

これまで申請者らは、低分子量GTPase Rab27aとそのエフェクター蛋白質exophilinsが、多細胞生物で高度に分化している刺激依存性の分泌経路(調節性分泌経路)で広く機能していることを報告してきた。これを反映して、Rab27a遺伝子の変異は、皮膚、毛髪の淡色化、免疫異常を引き起こすことが知られている。しかしRab27aのアイソフォームであるRab27bの機能については、研究が遅れていた。そこで申請者らは、Rab27b遺伝子のプロモーター直下にLacZ(β-galactosidare)遺伝子を導入したノックアウトマウスを作製した。本マウスはLacZ染色により、Rab27b遺伝子の発現を全組織で調べることができる。ヘテロマウスの染色の結果、Rab27bは内・外分泌細胞のみならず、脳、組織表面保護や機械伸展刺激を受ける細胞に広帆に発現していた。ホモ欠損マウスは、目立った表現型は認められなかったが、Rab27a/Rab27bダブルノックアウトマウスの下垂体内分泌細胞では、細胞膜近傍の分泌顆粒数が著明に低下しており、これら低分子量GTPaseが顆粒の細胞内輸送に関与していることが明らかになった。しかしながらホルモン分泌量に対する影響は軽度の低下を示すのみで、顆粒の細胞内における位置と開口放出頻度に明らかな関係がないことがわかった。これらの知見は、刺激により開口放出する分泌小胞は、必ずしも細胞膜近傍に存在するものではないことを示しており、これまでの通説を再考する必要性があることを示している。

Research Products

• [Journal Article] Exophilin 4/Slp2-a targets glucagon granules to the plasma membrane through unique Ca^<2+>-inhibitory phospholipid-binding activity of the C2A domain (2007)
  • Author(s): Yu M., et. al.
  • Journal Title: Mol. Biol. Cell 18 Pages: 688-696
  • Peer Reviewed
• [Journal Article] A subset of p23 localized on secretory granules in the pancreatic β-cells (2007)
  • Author(s): Hosaka M., et. al.
  • Journal Title: J. Histochem. Cytochem. 55 Pages: 235-245
  • Peer Reviewed
• [Journal Article] Structure of the small GTPase Rab27b shows an unexpected swapped dimer (2007)
  • Author(s): Chavas LMG, et. al.
  • Journal Title: Acta Cryst. D 63 Pages: 769-779
  • Peer Reviewed
• [Journal Article] Physiological roles of Rab27 effectors in regulated exocytosis (2007)
  • Author(s): Izumi T.
  • Journal Title: Endocrine J. 54 Pages: 649-657
  • NAID: 10020092451
  • Peer Reviewed
• [Journal Article] Rab27b is expressed in a wide range of exocytic cells and involved in the delivery of secretory granules near the plasma membrane (2007)
  • Author(s): Gomi H., et. al.
  • Journal Title: Mol. Biol. Cell 18 Pages: 4377-4386
  • Peer Reviewed
• [Journal Article] Secretory vesicle docking to the plasma membrane: molecular mechanism and functional significance (2007)
  • Author(s): Izumi T., et. al.
  • Journal Title: Diabetes, Obesity, and Metabolism 9 Pages: 109-117
• [Journal Article] Syntaxin 8 has two functionally distinct di-leucine-based motifs (2007)
  • Author(s): Kasai K., et. al.
  • Journal Title: Cell. Mol. Biol. Lett. 13 Pages: 144-154
  • Peer Reviewed
• [Journal Article] Exophilin4/Slp2-a targets glucagon granules to the plasma membrane through unique Ca^<2+>-inhibitory phospholipid-binding activity of the C2A domain (2007)
  • Author(s): Yu M., et al.
  • Journal Title: Mol.Biol.Cell 18(2) Pages: 688-696
• [Journal Article] A subset of p23 localized on secretory granules in the pancreatic β-cells (2007)
  • Author(s): Hosaka M., et al.
  • Journal Title: J.Histochem.Cytochem. 55(3) Pages: 235-245
• [Journal Article] Chromosome 2 locus Nidd5 has a potent effect on adiposity in the TSOD mouse (2006)
  • Author(s): Mizutani S., et al.
  • Journal Title: Mammalian Genome 17(5) Pages: 375-384
• [Journal Article] Granuphilin is activated by SREBP-1c and involved in impaired insulin secretion in diabetic mice (2006)
  • Author(s): Kato T., et al.
  • Journal Title: Cell Metabolism 4(2) Pages: 143-154
• [Journal Article] Rab27a mediates the tight docking of insulin granules onto the plasma membrane during glucose stimulation. (2005)
  • Author(s): Kasai K., et al.
  • Journal Title: J.Clin.Invest. 115 Pages: 388-396
• [Journal Article] Functional analysis of Rab27a effector granuphilin in insulin exocytosis. (2005)
  • Author(s): Izumi T., et al.
  • Journal Title: Methods Enzymol. 403 Pages: 216-229
• [Journal Article] Granuphilin molecularly docks insulin granules to the fusion machinery. (2005)
  • Author(s): Gomi H., et al.
  • Journal Title: J.Cell.Biol. 171 Pages: 99-109
• [Journal Article] Cytoplasmic transport signal is involved in phogrin targeting and localization to secretory granules. (2005)
  • Author(s): Torii S., et al.
  • Journal Title: Traffic 6 Pages: 1213-1224
• [Journal Article] Functional analysis of Rab27a effector granuphilin in insulin exocytosis. (2005)
  • Author(s): Izumi T., et al.
  • Journal Title: Methods Enzymol. 390 Part G(in press)
• [Journal Article] Rab27 effector granuphilin promotes the plasma membrane targeting of insulin granules via interaction with syntaxin 1a. (2004)
  • Author(s): Torii S., et al.
  • Journal Title: J.Biol.Chem. 279 Pages: 22532-22538
• [Journal Article] Rab27b localizes to zymogen granules and regulates pancreatic acinar exocytosis. (2004)
  • Author(s): Chem X., et al.
  • Journal Title: Biochem.Biophys.Res.Commun. 323 Pages: 1157-1162
• [Journal Article] Chromosome 2 locus Nidd5 has a potent effect on adiposity in the TSOD mouse.
  • Author(s): Mizutani S., et al.
  • Journal Title: Mammalian Genome (in press)
• [Presentation] TSODマウスの遺伝学的解析 (2007)
  • Author(s): 泉 哲郎
  • Organizer: 第3回TSOD(肥満・糖尿病)マウス研究会情報交換会
  • Place of Presentation: 東京
  • Year and Date: 2007-08-10
• [Presentation] Docking and fusion of endocrine granules in regulated exocytosis (2007)
  • Author(s): Tetsuro Izumi
  • Organizer: Metabolic syndrome and cellular signaling
  • Place of Presentation: Daegu, Korea
  • Year and Date: 2007-06-07
• [Presentation] インスリン顆粒のドッキング、フュージョンの分子機構 (2007)
  • Author(s): 泉 哲郎
  • Organizer: 第50回日本糖尿病学会年次学術集会(シンポジウム:小胞輸送と糖代謝調節)
  • Place of Presentation: 仙台
• [Presentation] グルカゴン顆粒の細胞膜への誘導を制御する膵α細胞特異的Rab27aエフェクター分子Exophilin 4 (2007)
  • Author(s): 河西和雄
  • Organizer: 第50回日本糖尿病学会年次学術集会
  • Place of Presentation: 仙台
• [Presentation] Granuphilinの発現はSREBP-1cにより活性化されインスリン分泌不全の原因となる (2007)
  • Author(s): 加藤豊範
  • Organizer: 第50回日本糖尿病学会年次学術集会
  • Place of Presentation: 仙台
• [Presentation] Exophilin4/Slp2-a targets glucagon granules to the plasma membrane through unique Ca^<2+>-inhibitory phospholipid-binding activity of the C2A domain (2007)
  • Author(s): Kazuo Kasai
  • Organizer: The 59th Annual Meeting of Japan Society for Cell Biology
  • Place of Presentation: Fukuoka
• [Presentation] ホルモン分泌の分子機構(教育講演) (2007)
  • Author(s): 泉 哲郎
  • Organizer: 第80回日本内分泌学会
  • Place of Presentation: 東京
• [Presentation] Roles of Rab27a and its effector granuphilin in insulin exocytosis (2007)
  • Author(s): Tetsuro Izumi
  • Organizer: 3rd Scientific Meeting of Asia-Pacific Diabetes and Obesity Study Group
  • Place of Presentation: Taizhou, China
• [Presentation] Docking and fusion of insulin granules in pancreatic beta cells (2007)
  • Author(s): Tetsuro Izumi
  • Organizer: International Symposium on Membrane Traffic
  • Place of Presentation: Awaji-shima, Hyogo, Japan
• [Book] 訳Ondine cieaver and Douglas A. Melton膵内分泌組織の発生Development of the endocrine pancreas. Chapter 2 in Kahn"Jolin's Diabetes Mellitus 14th edition(ジョスリン糖尿病学第2版) (2007)
  • Author(s): 泉 哲郎
  • Total Pages: 20
  • Publisher: メディカル・サイエンス・インターナショナル
• [Book] グラニュフィリンというタンパク質がインスリン分泌を抑制する.糖尿病最前線 ベンチノート (2007)
  • Author(s): 泉 哲郎
  • Total Pages: 1
  • Publisher: メディカル・ジャーナル社
• [Book] 2型糖尿病の動物モデルーげっ歯類.カラー版 糖尿病学 基礎と臨床 (2007)
  • Author(s): 泉 哲郎
  • Total Pages: 4
  • Publisher: 西村書店
• [Book] インスリン開口放出におけるGranuphilinの役割.特集「インスリン開口放出機構の最新の知見」 内分泌・糖尿病科 (2007)
  • Author(s): 泉 哲郎
  • Total Pages: 5
  • Publisher: 科学評論社
• [Remarks]
  • URL: http://imcr.showa.gunma-u.ac.jp/lab/geneeng/index.html
• [Publications] Izumi T., et al.: "Dominant negative pathogenesis by mutant proinsulin in the Akita diabetic mouse."Diabetes. 52・2. 409-416 (2003)
• [Publications] Yaguchi M., et al.: "Neurological study of C57BL/6Akita mouse, type 2 diabetic model : enhanced expression of αB-crystallin in oligodendrocytes."Neuropathology. 23・1. 44-50 (2003)
• [Publications] Zhang B., et al.: "Parathyroid hormone-related protein induces insulin expression through activation of MAP kinase-specific phosphatase-1 that dephosphorylates c-Jun NH2-terminal kinase in pancreatic β-cells."Diabetes. 52・1. 2720-2730 (2003)
• [Publications] Chen Y., et al.: "Rab27b is associated with fusiform vesicles and may be involved in targeting uroplakins to urothelial apical membranes."Proc.Natl.Acad.Sci., USA. 24. 14012-14017 (2003)
• [Publications] Izumi T., et al.: "Roles of Rab27 and its effectors in the regulated secretory pathways."Cell Struct. Funct.. 28・5. 465-474 (2003)
• [Publications] Hosaka M., et al.: "Secretogranin III binds to cholesterol in the secretory granule membrane as an adapter for chromogranin A."J.Biol.Chem.. 279. 3627-3634 (2004)
• [Publications] Fujisawa T., et al.: "Functional localization of proprotein-convertase furin and its substrate TGFβ in EGF Receptor-expressing gastric chief cells."Growth Factors. (in press). (2004)
• [Publications] Torii S., et al.: "Rab27 effector granuphilin promotes the plasma membrane targeting of insulin granules via interaction with syntaxin 1a."J.Biol.Chem.. 279(in press). (2004)