For whom the bell tolls: Linking protease degradomes with the proteasome through the N-end rule pathway to understand biological function.

细胞内蛋白酶切割蛋白质底物以显示多肽片段。这些片段是什么？它们是否具有新的活性？细胞如何调节它们的稳定性？这些问题是本提案的重点，它将首次尝试系统地结合植物蛋白生物化学的两个不同领域：蛋白酶的作用和泛素介导的多肽降解。它将解决一个新的假设，在这两个重要的影响，即N-末端规则途径是一个未发现的组件控制植物蛋白酶的生物学功能，通过连接蛋白酶靶泛素蛋白酶体系统。该项目将大大增加已知植物N-末端规则底物的数量，并将提供对植物蛋白酶作用后果的生物学理解。它将专注于植物免疫反应，并寻求发现新的N端规则底物，增强免疫反应。

Intracellular proteases cleave protein substrates to reveal polypeptide fragments. What are those fragments, do they have novel activities, and how does the cell regulate their stability? These questions are the focus of this proposal, that will attempt for the first time to systematically unite two different areas of plant protein biochemistry; the action of proteases and the ubiquitin-mediated degradation of polypeptides. It will address a novel hypothesis with important implications in both, that the N-end rule pathway is an undiscovered component controlling the biological function of plant proteases by linking protease targets to the ubiquitin proteasome system. The project will vastly increase the number of known plant N-end rule substrates, and will provide a biological understanding of the consequences of plant protease action. It will focus on the plant immune response and seek to uncover novel N-end rule substrate(s) that enhance the immune response.