Elucidation of the new signal transition pathway regarding auxin

阐明生长素的新信号转换途径

• 批准号: 09440263
• 负责人: NAGATA Toshiyuki
• 金额: $ 8.38万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09440263/
• 关键词: auxin; signal trnasduction pathway; tobacco mesophyll protoplasts; cell cycle; dedifferentiation; cytokinin; cell division; DNA合成; プロトプラスト; 信号伝達; 馴化細胞; 転写因子; イオンチャンネル; 出芽コウボ; 2ハイブリッドシシステム; タンパク質キナーゼC

Although auxin was discovered as the first plant hormone, its molecular mechanism is least understood. Thus, this study was-attempted to elucidate signal transduction pathways downstream from auxin application. As we have identified auxin-regulated genes, parA, parB and parC, in our previous study, we further characterized auxin-responsive elements to these genes and subsequetnly showed that there are specific binding proteins to these elements, which are supposed to be involved in auxin-signalling pathways. In the meantime, we found that cytokinin, which is requested for the induction of cell division in tobacco mesophyll protoplasts, was found to play a critical role for the entry into cell cycle. It seems that cell cycle entry was triggered by cytokinin and the cell cycle progression was further facilitated by the gene products of auxin-regulated genes of parA, parB and parC, which encode different types of glutathione S-transferases. This is a completely new interpretation for the … More entry of tobacco mesophyll protoplasts into cell cycle progression, resulting in active cell division.On the other hand, regarding auxin-signalling pathways for tobacco BY-2 cell proliferation, we have identified an auxin-regualted gene, arcA, upon the addition of auxin to the auxin-starved BY-2 cells. In this case, involvement of β-subunit of KィイD1+ィエD1-ion channel proteins was proposed, but we have not gotten decisive conclusion for this pathway. However, we have identified another completely new pathway for auxin signalling. When we added culture filtrates of auxin-habituated 2B-13 cells to the auxin-starved BY-2 cells, we could see the induction of cell division in these cells. This was hot due to the low molecular weight plant hormones in the culture filtrates, but rather to higher molecular mass proteins. Further elucidation of the protein by a gel filtration using Sephadex G25 revealed that it was due to ca. 30 kDa protein. Though the nature of this protein has not been determined yet, it is certain that there is a new signalling pathway downstream from auxin application, as there has been reported no such pathways. Less

尽管生长素被发现为第一个植物，但其分子机制最少被理解。这是为了阐明生长素应用下游的信号转导途径而被取消。正如我们在先前的研究中确定了生长素调节的基因，Para，parb和Parc，我们进一步表征了对这些基因的生长素反应元素，并进行了表明，这些元素与这些元素有特定的结合蛋白，这些元素应与生长素 - 签名途径有关。同时，我们发现烟草叶肉原生质体中需要诱导细胞分裂的细胞分裂素在进入细胞周期中起着至关重要的作用。看来细胞周期的进入是由细胞分裂素触发的，并且由PARA，PARB和PARC的生长素调节基因的基因产物进一步制备了细胞周期的进程，该基因编码不同类型的谷胱甘肽S-转移酶。这是……对……更多的烟草叶叶叶原生质体进入细胞周期进程的全新解释，从而导致活性细胞分裂。另一方面，关于烟草By-2细胞增殖的生长素签名途径，我们在向生长素恒定的By-2细胞中添加了生长素后，鉴定了生长素恢复的基因ARCA。在这种情况下，提出了KYI D1+IE D1-ION通道蛋白的β-亚基的参与，但我们尚未获得该途径的决定性结论。但是，我们已经确定了生长素信号传导的另一种全新途径。当我们将生长素摄取的2B-13细胞的培养物过滤器添加到恒星的BY-2细胞中时，我们可以看到这些细胞中细胞分裂的诱导。由于培养物过滤器中的分子量低，而是由于较高的分子质量蛋白，这很热。使用Sephadex G25通过凝胶过滤进一步阐明该蛋白质表明，这是由于Ca所致。 30 kDa蛋白。尽管尚未确定该蛋白质的性质，但可以肯定的是，由于没有这种途径，因此生长素应用下游有一个新的信号通路。较少的

项目成果

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