オーキシン情報伝達系の分子機構研究

• Project/Area Number: 14036201
• Research Category: Grant-in-Aid for Scientific Research on Priority Areas
• Allocation Type: Single-year Grants
• Review Section: Biological Sciences
• Research Institution: Hokkaido University
• Principal Investigator: 山本 興太朗 北海道大学, 大学院・理学研究院, 教授 (80142008)
• Co-Investigator(Kenkyū-buntansha): 綿引 雅昭 北海道大学, 大学院・理学研究院, 助手 (70396282)
• Project Period (FY): 2002 – 2006
• Project Status: Completed (Fiscal Year 2006)
• Budget Amount: ¥111,300,000 (Direct Cost: ¥111,300,000); Fiscal Year 2006: ¥22,200,000 (Direct Cost: ¥22,200,000); Fiscal Year 2005: ¥22,200,000 (Direct Cost: ¥22,200,000); Fiscal Year 2004: ¥22,200,000 (Direct Cost: ¥22,200,000); Fiscal Year 2003: ¥22,200,000 (Direct Cost: ¥22,200,000); Fiscal Year 2002: ¥22,500,000 (Direct Cost: ¥22,500,000)
• Keywords: オーキシン / ルシフェラーゼ融合タンパク質 / 蛍光相関分光法 / タンパク質分解調節 / オーキシン応答因子 / Aux / IAAタンパク質 / 偏差成長 / 伸長成長 / 屈性 / 稔性 / 受粉 / 雄蘂 / 花糸 / 遺伝子 / シグナル伝達 / 植物 / 発生・分化 / 発現制御 / 信号伝達系 / 遺伝子発現 / 突然変異体

Research Abstract

MSG2タンパク質を検出するために、ルシフェラーゼ融合タンパク質として検出することを試みた。その結果、シロイヌナズナ黄化芽生えでのMSG2 promoter (pMSG2)::MSG2::LUC活性は、pMSG2::LUCの1/10程度だった。この差がMSG2タンパク質にかかる分解調節だと考えられる。このMSG2::LUC活性はプロモーター活性同様、オーキシン処理によって早期に増加した。明所で栽培した芽生えでは、プラシノステロイドによってMSG2のメッセージが増加することが報告されているが、MSG2::LUCを用いて調べたところ、MSG2タンパク質レベルも同様に増加することが分かった。Aux/IAAとARFとの相互作用を物理的な蛍光相関分光法(fluorescence correlation spectroscopy)を用いて測定した。Aux/IAAとしては、MSG2とAXR2とSLR、 ARFのタンパク質問相互作用ドメインとしてはNPH4/ARF7とMP/ARF5のドメインIIIとドメインIV(CTD)を選んで、両者をHeLa細胞に一過的に発現させ、蛍光強度の相関係数を測定した。その結果、Aux/IAAとARF-CTDの相互作用は強く、両者はほぼ100%結合すること、一方Aux/IAA同士、またはARF-CTD同士の結合は比較的弱く、この場合は20%程度しか結合していないことが分かった。このことは、Aux/IAAレベルの小さい変動でもARFの結合状態を変化させうることを示唆している。

Research Products

• [Journal Article] Differential expression of the auxin primary-response gene MASSUGU2/IAA19 during tropic responses of Arabidopsis hypocotyls. (2007)
  • Author(s): Saito, K.
  • Journal Title: Physiol. Plant. 130 Pages: 148-156
• [Journal Article] Specificity and similarity of functions of the Aux/IAA genes in auxin signaling of Arabidopsis revealed by promoter-exchange experiments between MSG2/IAA19, AXR2/IAA3 and SLR/IAA14. (2007)
  • Author(s): Muto, H.
  • Journal Title: Plant Physiol. 143・5(印刷中)
• [Journal Article] What makes each Aux/IAA gene unique in its gene family, expression pattern or properties of the gene product? (2007)
  • Author(s): Muto, H.
  • Journal Title: Plant Signaling ＆ Behavior 2(印刷中)
• [Journal Article] Inhibition of brassinosteroid biosynthesis by either a dwarf4 mutation or a brassinosteroid biosynthesis inhibitor rescues defects in tropic responses of hypocotyls in the Arabidopsis mutant, non-phototropic hypocotyl 4. (2006)
  • Author(s): Nakamoto, D.
  • Journal Title: Plant Physiol. 141 Pages: 456-464
• [Journal Article] Fluorescence cross-correlation analyses of molecular interaction between Aux/IAA protein and protein-protein interaction domain of auxin response factors of Arabidopsis expressed in HeLa cells. (2006)
  • Author(s): Muto, H.
  • Journal Title: Plant Cell Physiol. 47 Pages: 1095-1101
• [Journal Article] Overexpression of RADICAL INDUCED CELL DEATHl (RCDl) gene of Arabidopsis causes weak rcdl phenotype with compromised oxidative-stress responses. (2006)
  • Author(s): Fujibe, T.
  • Journal Title: Biosci. Biotech. Biochem. 70 Pages: 1827-1831
• [Journal Article] Isolation of a mutant of Ferl gene, acting synergistically with the ARF8 gene to control development of the anther and filament in Arabidopsis. (2005)
  • Author(s): Tian, C.E.
  • Journal Title: J.Integ.Plant Biol 47 Pages: 327-333
• [Journal Article] The Arabidopsis SHORT VALVE protein, responsible for translation reinitiation, is required for anxin-mediated gynoecium patterning. (2005)
  • Author(s): Nishimura, T.
  • Journal Title: Plant Cell 17 Pages: 2940-2953
• [Journal Article] Disruption and overexpression of Auxin Response Factor 8 gene of Arabidopsis affect hypocotyl elongation and root growth habit, indicating its possible involvement in auxin homeostasis in light condition. (2004)
  • Author(s): Tian, C.-e., Muto, H., Higuchi, K., Matamura, T., Tatematsu, K., Koshiba, T., Yamamoto, K.T.
  • Journal Title: Plant J. 40 Pages: 333-333
• [Journal Article] Overexpression of CONSTITUTIVE DIFFERENTIAL GROWTH 1 gene, which encodes a RLCKVII-subfamily protein kinase, causes abnormal differential and elongation growth after organ differentiation in Arabidopsis. (2004)
  • Author(s): Muto, H., Yabe, N., Asami, T., Hasunuma, K., Yamamoto, K.T.
  • Journal Title: Plant Physiol. 136 Pages: 3124-3124
• [Book] Methods in Molecular Biology (2007)
  • Author(s): Muto, H.
  • Publisher: Humana Press, Totowa, NJ(印刷中)
• [Publications] Fujibe, T., Saji, H., Arakawa, K., Yabe, N., Takeuchi, Y, Yamamoto, K.T.: "A methyl viologen-resistant mutant of Arabidopsis, which is allelic to ozone-sensitive rcd1, is tolerant to supplemental ultraviolet-B irradiation."Plant Physiology. 134. 275-285 (2004)
• [Publications] Tatematsu, K., Kumagai, S., Muto H., Sato, A., Watahiki, M.K., Harper, R.M., Liscum, B., Yamamoto, K.T.: "MASSUGU2 encodes Aux/IAA19, an auxin-regulated protein that functions together with the transcriptional activator NPH4/ARF7 to regulate differential growth responses of hypocotyl and formation of lateral roots in Arabidopsis."Plant Cell. 16. 379-393 (2004)
• [Publications] Imai, A., Akiyama, T., Kato, T., Sato, S., Tabata, S., Yamamoto, K.T., Takahashi, T.: "Spermine is not essential for survival of Arabidopsis."FEBS Letters. 556. 148-152 (2004)