RP1: Identification of ubiquitin-dependent pathways involved in neuron-specific protein degradation

泛素/蛋白酶体系统(UPS)是消除错误折叠或调节蛋白的关键，对神经元的正常发育和功能起着至关重要的作用。几个泛素分子以多泛素链的形式连接在一起通常涉及三类酶：泛素激活酶(EL)、泛素结合酶(E2)和泛素连接酶(E3)。然而，在某些情况下，多泛素化需要泛素链延长因子的额外活性，称为E4酶。我们拟议的研究的中心目标是确定参与神经元特异性蛋白质降解的泛素依赖途径。利用基于绿色荧光蛋白(GFP)的底物可以快速定量泛素依赖的蛋白降解，我们建立了模式生物秀丽线虫不同组织的体内降解实验。识别神经元和其他组织特有的蛋白分解途径将为了解UPS和神经元分化提供新的机制见解。

The ubiquitin/proteasome system (UPS) is pivotal for the elimination of misfolded or regulatory proteins, and plays a crucial role in correct neuronal development and function. Attachment of several ubiquitin molecules in form of a polyubiquitin chain usually involves three classes of enzymes: a ubiquitin-activating enzyme (El), a ubiquitinconjugating enzyme (E2), and a ubiquitin ligase (E3). In some cases however polyubiquitylation requires the additional activity of ubiquitin chain elongation factors, termed E4 enzymes.The central objective of our proposed research is to identify ubiquitin-dependent pathways involved in neuron-specific protein degradation. Using green fluorescent protein (GFP)-based substrates that allow rapid quantification of ubiquitin-dependent proteolysis, we have established an in vivo degradation assay in different tissues of the model organism Caenorhabditis elegans. The identification of proteolytic pathways specific for neurons and other tissues will provide novel mechanistic insights into the UPS and neuronal differentiation.