Analysis of the PUB22 ubiquitin ligase mediated regulation of exocyst-dependent exocytosis during plant immune responses

植物免疫反应过程中 PUB22 泛素连接酶介导的胞吐依赖性胞吐作用的调节分析

• 批准号: 195694284
• 负责人: Professor Dr. Marco Trujillo Linke
• 金额: --
• 依托单位: Lehrstuhl für Pflanzenphysiologie
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2011
• 资助国家: 德国
• 起止时间: 2010-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/195694284?language=en
• 关键词: Analysis; PUB22; ubiquitin; ligase; mediated

We have shown that the plant u-box type E3 ubiquitin ligases triplet PUB22-PUB24, is a negative regulator of PAMP-triggered signalling and immunity. Ubiquitin ligases are at the heart of the ubiquitination process because they specify the ubiquitination target. We’ve identified an Arabidopsis homologue of the Exo70 subunit (Exo70h1) of the Exocyst complex as a ubiquitination target of PUB22, the main ligase of the triplet. The exocyst is an octameric complex that mediates early steps of exocytosis, termed ‘tethering’, and little is known about its function in plants. Our work shows that Exo70 is required for signalling triggered by biotic cues and immune responses suggesting that the phenotype observed in pub22-pub24 mutant plants is, at least in part, caused by the targeting of Exo70h1. However, the reason why the regulation of the Exocyst complex would lead to altered signalling and immune responses remains open. In this project we aim at elucidating the potential functions of PUB22-PUB24 and Exo70h1 by identifying the intracellular compartment(s) in which they’re localized. Furthermore, we’ll study the interaction and the targeting of Exo70h1 by PUB22 and that of homologues to decipher possible regulation networks. We will also investigate the link between PUB22-PUB24 and the modulation of receptor levels, as shown by our preliminary data, which suggests a potential link to exocytosis and therefore Exo70h.

我们已经表明，植物u-box型E3泛素连接酶三联体PUB 22-PUB 24是PAMP触发的信号传导和免疫的负调节剂。泛素连接酶是泛素化过程的核心，因为它们指定了泛素化的靶点。我们已经确定了外囊复合物的Exo 70亚基（Exo 70 h1）的拟南芥同源物作为PUB 22（三联体的主要连接酶）的泛素化靶标。外孢囊是一种八聚体复合物，介导胞吐作用的早期步骤，称为“拴系”，但对其在植物中的功能知之甚少。我们的工作表明，Exo 70是由生物信号和免疫反应触发的信号所必需的，这表明在pub 22-pub 24突变体植物中观察到的表型至少部分是由Exo 70 h1的靶向引起的。然而，为什么外囊复合物的调节会导致信号传导和免疫反应的改变仍然是开放的。在这个项目中，我们的目标是阐明PUB 22-PUB 24和Exo 70 h1的潜在功能，通过确定它们定位的细胞内区室。此外，我们将研究PUB 22与Exo 70 h1的相互作用和靶向作用，以及同源物的相互作用和靶向作用，以破译可能的调控网络。我们还将研究PUB 22-PUB 24与受体水平调节之间的联系，如我们的初步数据所示，这表明与胞吐作用以及因此与Exo 70 h之间存在潜在联系。