アポトーシスにおける細胞質から核への情報伝達メカニズム

• Project/Area Number: 11237204
• Research Category: Grant-in-Aid for Scientific Research on Priority Areas
• Allocation Type: Single-year Grants
• Review Section: Biological Sciences
• Research Institution: Osaka University
• Principal Investigator: 辻本 賀英 大阪大学, 医学系研究科, 教授 (70132735)
• Co-Investigator(Kenkyū-buntansha): 清水 重臣 大阪大学, 医学系研究科, 助教授 (70271020) ; 恵口 豊 大阪大学, 医学系研究科, 助教授 (20243206)
• Project Period (FY): 1999 – 2003
• Project Status: Completed (Fiscal Year 2003)
• Budget Amount: ¥60,900,000 (Direct Cost: ¥60,900,000); Fiscal Year 2003: ¥12,100,000 (Direct Cost: ¥12,100,000); Fiscal Year 2002: ¥12,100,000 (Direct Cost: ¥12,100,000); Fiscal Year 2001: ¥12,000,000 (Direct Cost: ¥12,000,000); Fiscal Year 2000: ¥12,000,000 (Direct Cost: ¥12,000,000); Fiscal Year 1999: ¥12,700,000 (Direct Cost: ¥12,700,000)
• Keywords: アポトーシス / 核 / ミトコンドリア / プログラム細胞死 / カスペース / シトクロムc / DNA傷害 / Acinus / Bcl-2

Research Abstract

アポトーシス時には、細胞内コンパートメントを越えてシグナル伝達が行なわれるが、我々は、特にミトコンドリア、細胞質、核の間でのシグナル伝達機構の解明に取り組んできた。種々のアポトーシスシグナルは最終的にミトコンドリアに集約され、カスペース活性化因子シトクロムcなどの細胞質への漏出を惹起し、カスペースを活性化させる。カスペースは種々や細胞質内たんぱくを切断し、アポトーシスに特徴的な構造変化を誘導する。
本年度の成果は以下の通りである。
DNA傷害(特にDNA2重鎖切断)により誘導されるアポトーシスにおいて核からどのようにして、アポトーシス信号がミトコンドリアに伝達されるかを解明するために、単離ミトコンドリアを用いたアッセイ系を利用し、DNA2重鎖切断により惹起されるシトクロムc漏出誘導因子の精製を通し、リンカーヒストンの一つH1.2を同定した。H1.2遺伝子発現のサイレンシングやH1.2ノックアウトマウスを用い、DNA2重鎖切断により誘導されるアポトーシスにおけるH1.2の重要な役割の確証を得た。DNA2重鎖切断によりH1.2が核より細胞質に遊離することとその遊離にp53が必須であることも示した。

Research Products

• [Publications] Tsujimoto, Y.: "Cell death regulation by the Bcl-2 protein family in the mitochondria"J.Cell.Physiol.. 167. 158-167 (2003)
• [Publications] Konishi, A.: "Involvement of histone H1.2 in apoptosis induced by DNA double-strand breaks."Cell. 114. 673-688 (2003)
• [Publications] Sugioka, R.: "BH4-domain peptide from Bcl-xL exerts anti-apoptotic activity in vivo."Oncogene. 22. 8432-8440 (2003)
• [Publications] Shinzawa, K.: "PLA2 activity is required for nuclear shrinkage in caspase-independent cell death."J.Cell Biol.. 163. 1219-1230 (2003)
• [Publications] Tsujimoto, Y.: "The voltage-dependant anion channel : an essential player in apoptosis"Biochimie. 9. 187-193 (2002)
• [Publications] Tsujimoto, Y.: "Bcl-2 family of proteins : life-or-death switch in mitochondria"Bioscience Report. 22. 47-58 (2002)
• [Publications] Sugiyama, T.: "Activation of mitochondrial voltage-dependent anion channel by a pro-apoptotic BH3-only protein Bim"Oncogene. 21. 4944-4956 (2002)
• [Publications] Akao, Y.: "Apoptosis induced by N-methyl(R)salsolinol, an endogenous neurotoxin, is mediated by mitochondrial permeability transition and suppressed by Bcl-2 and rasagiline, N-prooargyl-1(R)-aminoindan"J.Neurochem.. (in press). (2002)
• [Publications] Lee, M.: "Reactive astrocytes express bis, a bcl-2-binding protein, after transient forebrain ischemia"Exp Neurol.. 175. 338-346 (2002)
• [Publications] Nomura, M.: "14-3-3 interacts directly with and negatively regulates pro-apoptotic Bax"J. Biol. Chem.. (in press). (2002)
• [Publications] Tsujimoto, Y.: "Apoptosis the molecular biology of programmed cell death eds.M.D. Jaconson & N.McCarthy"Oxford Univ. press. 321 (2002)
• [Publications] Shimizu, S.: "Essential role of voltage-dependent anion channel in various forms of apoptosis in mammalian cells"J.Cell Biology. 152. 237-250 (2001)
• [Publications] Tsujimoto, Y.: "The voltage-dependent anion channel : an essential role in apoptosis"Biochimie. (in press). (2001)
• [Publications] Shimizu,S.: "Pro-apoptotic BH3-only Bcl-2 family members induce cytochrome c release, but not mitochondrial membrane potential loss......"Proc.Natl.Acad.Sci.USA.. 97. 577-582 (2000)
• [Publications] Shimizu,S.: "BH4 domain of anti-apoptotic Bcl-2 family members closes VDAC, and inhibits apoptotic mitochondrial changes and cell death."Proc.Natl.Acad.Sci.USA.:. 97. 3100-3105 (2000)
• [Publications] Shimizu,S.: "Electrophysiological study of a novel large pore formed by Bax and VDAC, which is permeable to cytochrome c"J.Biol.Chem.:. 275. 12321-12325 (2000)
• [Publications] Shimizu,S.: "Bax and Bcl-xL independently regulate apoptotic changes of yeast mitochondria that require VDAC but not adenine nucleotide translocato"Oncogene. 19. 4309-4318 (2000)
• [Publications] Kusano,H.: "Human gelsolin prevents apoptosis by inhibiting apoptotic mitochondrial changes via closing VDAC."Oncogene. 19. 4807-4814 (2000)
• [Publications] Shimizu,S.: "Essential role of voltage-dependent anion channel in various forms of apoptosis in mammalian cells."J.Cell Biol.. (印刷中). (2000)
• [Publications] Eguchi, Y.: "ATP-dependent steps in apoptotic signal transduction"Cancer Res.. 59. 2174-2181 (1999)
• [Publications] Shimizu, S.: "Bcl-2 family protein s regulate the release of apoptogenic cytochrome c by the mitochondrial channel VDAC"Nature. 399. 483-487 (1999)
• [Publications] Lee, J. -H.: "Bis, a Bcl-2-binding protein that synergizes with Bcl-2 in preventing cell death"Oncogene. 18. 6183-6190 (1999)
• [Publications] Ohtsubo, T.: "Identification of NHF2, a member of the NF-E2 family of transcription factors, as a substrate for caspase-2(-like)"Cell Death Diff.. 6. 865-872 (1999)
• [Publications] Sahara, S.: "Acinus is a caspase-3-activated protein required for apoptotic chromatin condensation"Nature. 401. 168-173 (1999)
• [Publications] Nomura, M.: "Apoptotic cytosol facilitates Bax translocation to mitochondria that involves cytosolic factor regulated by Bcl-2"Cancer Res.. 59. 5542-5548 (1999)