Role Of A Lys63-Specific E2 Ubiquitin-Conjugating Enzyme/Variant In Plant Innate Immunity

泛素化是一种主要的真核蛋白修饰过程，它将泛素这种高度保守的小蛋白附着在底物上。泛素化过程包括三个连续的酶促反应，分别由泛素活化酶（E1）、泛素偶联酶（E2）和泛素连接酶（E3）催化。近年来，泛素化已成为植物抗多种病原体免疫的重要调控机制。几种植物E3连接酶已被证明是宿主免疫和免疫相关细胞死亡的积极或消极调节因子。相比之下，E2酶在植物免疫中的作用，特别是那些指导非经典赖氨酸63特异性泛素化的酶，实际上是未知的。打开植物免疫的新视角，研究人员发现番茄防御细菌病原体的E2泛素结合酶可以指导赖氨酸63特异性泛素化。本课题研究人员将对植物免疫中赖氨酸63连接泛素化的关键组分进行表征，这对了解泛素化系统对植物免疫的调控具有重要意义。此外，这项工作将有助于揭示由赖氨酸63连接泛素化控制的生物过程和蛋白质，目前对其了解非常有限。该项目的组成部分是培养来自科学领域代表性不足的少数民族的博士后、研究生和本科生；将该项目的研究结果纳入PI所在机构的本科/研究生水平实验课程中，目前少数民族学生占学生总数的30%以上；并与阿肯色合作推广服务处合作，将该项目的调查结果分发给公众和利益相关者。

Ubiquitination is a major eukaryotic protein modification process that attaches ubiquitin, a highly conserved small protein, to substrates. The ubiquitination process involves three consecutive enzymatic reactions that are catalyzed by ubiquitin-activating enzyme (E1), ubiquitin-conjugating enzyme (E2) and ubiquitin ligase (E3), respectively. In recent years, ubiquitination has emerged as a key regulatory mechanism of plant immunity against many pathogens. Several plant E3 ligases have been shown to act as either positive or negative regulators of host immunity and immunity-associated cell death. In contrast, roles of E2 enzymes in plant immunity, particularly those that direct non-classical lysine 63-specific ubiquitination, are virtually unknown. Opening a new perspective on plant immunity, the investigators have implicated in tomato defense against a bacterial pathogen an E2 ubiquitin-conjugating enzyme that directs lysine 63-specific ubiquitination. In this project the investigators will characterize key components of lysine 63-linked ubiquitination in plant immunity, which is of fundamental importance to the understanding of the regulation of plant immunity by the ubiquitination system. Additionally, this work will assist in efforts to unravel biological processes and proteins that are controlled by lysine 63-linked ubiquitination, knowledge of which is very limited at present. Integral to this project is training of post-doctoral, graduate and undergraduate students from minority groups that are underrepresented in science; incorporation of findings from this project to a dual-listed undergraduate-/graduate-level laboratory course taught at the PI's institution, where minority students currently make up over 30% of the student population; and partnering of the investigators with the Arkansas Cooperative Extension Service to distribute findings from this project to the general public and stakeholders.