1996 Fiscal Year Annual Research Report

核・細胞質間のコミュニケーション

Research Project

Project/Area Number	07282103
Research Institution	Osaka University
Principal Investigator	米田悦啓大阪大学, 医学部, 教授 (80191667)
Co-Investigator(Kenkyū-buntansha)	東義明九州大学, 大学院・医学系研究科, 助手安達喜文京都大学, 化学研究所, 助手 (50201893) 恵口豊大阪大学, 医学部, 助教授 (20243206) 藤田尚志東京都臨床医学総合研究所, 腫瘍細胞研究部門, 室長 (10156870) 大島靖美九州大学, 理学部, 教授 (90037606)
Keywords	核蛋白質輸送 / mRNA輸送 / 核膜孔ターゲティング複合体 / 核膜孔 / アポトーシス / 細胞核 / 細胞内情報伝達
Research Abstract	細胞核と細胞質の間の情報交換のメカニズムを分子レベルで解明することは、細胞核の機能的構築を解明していく上で重要であると考え、主として、核膜孔を介した蛋白質やmRNAの輸送のメカニズムの解析を進め、以下のような成果を得た。 1.細胞外刺激を受けてはじめて細胞質から核へ移行する蛋白質の代表として、転写因子の1つであるStat1に着目し、その輸送メカニズムを解析した。その結果、細胞質において核局在化シグナル(NLS)が認識されるステップが、SV40T抗原のように構成的に核内に運ばれる蛋白質と全く異なり、NLS受容体として分離された分子の1つであるNPI-1によって特異的に運ばれ、もう1つのグループに属するRch1は全く関与しないことがわかった。 2.分裂酵母S.pombeを用いて、mRNA輸送に異常を示す温度感受性変異株を複数樹立し、その変異を相補する遺伝子の同定を行った。その結果、mrt-2とmrt-3と呼ぶ2つの株について、遺伝子が同定でき、それぞれ、細胞周期に関与する遺伝子であるpim-1^+とユビキチン活性化酵素E1のホモログであることがわかった。 3.Bcl-2,Bcl-x_Lによって抑制される各種細胞死において、Bcl-2,Bcl-x_LはICEファミリープロテアーゼの活性化シグナル伝達経路を上流で遮断することにより、細胞死を抑制していることがわかった。また、細胞死において、核内で起こる変化を誘導するため、何らかの因子が能動的に核内に輸送されることが必要であることが明らかとなった。 4.核膜孔に存在する巨大なRan結合蛋白質RanBP2は、核膜孔ターゲティング複合体の1つの構成因子であるPTAC97と結合することがわかった。以上のように、核一細胞質間物質輸送のメカニズムに関して、研究計画に沿った成果が得られた。

Research Products
(19 results)

All Other

All Publications (19 results)

[Publications] Toshinao Kurihara: "Partial purifaication and charcterization of a protein kinase that is activated by nuclear localization signal peptides." FEBS Lett.380. 241-245 (1996)
[Publications] Shigeru Kawahire: "Subcellular distribution and phosphorylation of the nuclear localization signal binding protein,NBP60." Exp.Cell Res.222. 385-394 (1996)
[Publications] Kanji Yoshida: "Targeted disruption of gp130,a common signal trqansducer for the interleukine 6 family of cytokines,leads to myocardial and hematological disorders." Proc.Natl.Acad.Sci.USA. 93. 407-411 (1996)
[Publications] Taro Tachibana: "Exogenously injected nuclear import factor p10/NTF2 inhibits signal-mediated nuclear import and export of proteins in living cells." FEBS Lett.397. 177-182 (1996)
[Publications] Toshihiro Sekimoto: "Interferon-g-dependent nuclear import of Statl is mediated by the GTPase activity of Ran/TC4." J.Biol.Chem.271. 31017-31020 (1996)
[Publications] Hiroshi Kajikawa: "Expression of highly polysialylated NCAM(NCAM-H) in developing and adult chicken auditory organ." Hearing Res.103. 123-130 (1997)
[Publications] Noriko Yasuhara: "Essential role of active nuclear transport in apoptosis." Genes to Cells. (in press). (1997)
[Publications] Mitsutoshi Yoneyama: "Autocrine amplification of the type I interferon gene expression mediated by interferon stimulated gene factor 3(ISGF3)." J.Biochem.120. 160-169 (1996)
[Publications] Wakako Suhara: "Structure of mouse interferon stimulated gene factor 3γ(ISGF3γ/p48) cDNA and chromosomal localization of the gene." J.Biochem.119. 231-234 (1996)
[Publications] Seiichi Urushiyama: "Isolation of novel pre-mRNA splicing mutants of Schizosaccharomyces pombe." Mol.Gen.Genet.(in press).
[Publications] Reiko Hirai: "A human transforming growth factor-β type II redceptor that contains an insertion in the extracellular domain." Exp.Cell Res.223. 135-141 (1996)
[Publications] Shigeomi Shimizu: "Bcl-2 blocks loss of mitochondrial membrane potential while ICE inhibitors act at a differnt step during inhibition of death induced by respiratory chain inhibitors." Oncogene. 13. 21-29 (1996)
[Publications] Shigeomi Shimizu: "Bcl-2 expression prevents activation of the ICE protease cascade" Oncogene. 12. 2251-2257 (1996)
[Publications] Shigeomi Shimizu: "Induction of apoptosis as well as necrosis by hypoxia,and predominant prevention of apoptosis by Bcl-2 and Bcl-x_L." Cancer Res.56. 2161-2166 (1996)
[Publications] Shigeomi Shimizu: "Retardation of chemical hypoxia-induced necrotic cell death by Bcl-2 and ICE inhibitors:possible involvement of common mediators in apoptotic and necrotic signal transducers." Oncogene. 12. 2045-2050 (1996)
[Publications] Yoshiaki Azuma: "Conserved histidine recidues of RCCl are essential for nucleotide exchange on Ran." J.Biochem.120. 82-91 (1996)
[Publications] Tomoyuki Ohba: "Premature chromatin condensation induced by loss of RCCl is inhibited by GTP-and GTPγS-Ran,but not GDP-Ran." J.Biol.Chem.271. 14665-14667 (1996)
[Publications] Yoshihiro Yoneda: "Membrane Protein:Structure,Function and Expression Control" Karger Medical and Scientific Publishers, 413 (1997)
[Publications] 米田悦啓: "細胞核ネットワーク" 羊土社, 112 (1996)

1996 Fiscal Year Annual Research Report

核・細胞質間のコミュニケーション

Principal Investigator

米田 悦啓 大阪大学, 医学部, 教授 (80191667)

Research Products

[Publications] Toshinao Kurihara: "Partial purifaication and charcterization of a protein kinase that is activated by nuclear localization signal peptides." FEBS Lett.380. 241-245 (1996)

[Publications] Shigeru Kawahire: "Subcellular distribution and phosphorylation of the nuclear localization signal binding protein,NBP60." Exp.Cell Res.222. 385-394 (1996)

[Publications] Kanji Yoshida: "Targeted disruption of gp130,a common signal trqansducer for the interleukine 6 family of cytokines,leads to myocardial and hematological disorders." Proc.Natl.Acad.Sci.USA. 93. 407-411 (1996)

[Publications] Taro Tachibana: "Exogenously injected nuclear import factor p10/NTF2 inhibits signal-mediated nuclear import and export of proteins in living cells." FEBS Lett.397. 177-182 (1996)

[Publications] Toshihiro Sekimoto: "Interferon-g-dependent nuclear import of Statl is mediated by the GTPase activity of Ran/TC4." J.Biol.Chem.271. 31017-31020 (1996)

[Publications] Hiroshi Kajikawa: "Expression of highly polysialylated NCAM(NCAM-H) in developing and adult chicken auditory organ." Hearing Res.103. 123-130 (1997)

[Publications] Noriko Yasuhara: "Essential role of active nuclear transport in apoptosis." Genes to Cells. (in press). (1997)

[Publications] Mitsutoshi Yoneyama: "Autocrine amplification of the type I interferon gene expression mediated by interferon stimulated gene factor 3(ISGF3)." J.Biochem.120. 160-169 (1996)

[Publications] Wakako Suhara: "Structure of mouse interferon stimulated gene factor 3γ(ISGF3γ/p48) cDNA and chromosomal localization of the gene." J.Biochem.119. 231-234 (1996)

[Publications] Seiichi Urushiyama: "Isolation of novel pre-mRNA splicing mutants of Schizosaccharomyces pombe." Mol.Gen.Genet.(in press).

[Publications] Reiko Hirai: "A human transforming growth factor-β type II redceptor that contains an insertion in the extracellular domain." Exp.Cell Res.223. 135-141 (1996)

[Publications] Shigeomi Shimizu: "Bcl-2 blocks loss of mitochondrial membrane potential while ICE inhibitors act at a differnt step during inhibition of death induced by respiratory chain inhibitors." Oncogene. 13. 21-29 (1996)

[Publications] Shigeomi Shimizu: "Bcl-2 expression prevents activation of the ICE protease cascade" Oncogene. 12. 2251-2257 (1996)

[Publications] Shigeomi Shimizu: "Induction of apoptosis as well as necrosis by hypoxia,and predominant prevention of apoptosis by Bcl-2 and Bcl-x_L." Cancer Res.56. 2161-2166 (1996)

[Publications] Shigeomi Shimizu: "Retardation of chemical hypoxia-induced necrotic cell death by Bcl-2 and ICE inhibitors:possible involvement of common mediators in apoptotic and necrotic signal transducers." Oncogene. 12. 2045-2050 (1996)

[Publications] Yoshiaki Azuma: "Conserved histidine recidues of RCCl are essential for nucleotide exchange on Ran." J.Biochem.120. 82-91 (1996)

[Publications] Tomoyuki Ohba: "Premature chromatin condensation induced by loss of RCCl is inhibited by GTP-and GTPγS-Ran,but not GDP-Ran." J.Biol.Chem.271. 14665-14667 (1996)

[Publications] Yoshihiro Yoneda: "Membrane Protein:Structure,Function and Expression Control" Karger Medical and Scientific Publishers, 413 (1997)

[Publications] 米田悦啓: "細胞核ネットワーク" 羊土社, 112 (1996)

米田悦啓大阪大学, 医学部, 教授 (80191667)