Targeted degradation of proteins by affinity peptide conjugated ubiquitin (APCU)

亲和肽结合泛素（APCU）靶向降解蛋白质 蛋白质降解具有许多DNA/RNA操作无法涵盖的独特性质 工具.为了了解生物过程的机制，并达到理想的治疗效果， 迫切需要设计用于诱导蛋白质降解的技术。然而，很少有选择是 目前用于此类目的。此外，现有的工具具有已知的局限性，例如难以 适应或钟形剂量反应曲线，或脆弱性的负调控的去， 泛素化系统为了扩大工具的选择，并克服现有方法的局限性，我们 我建议建立一种新的方法，通过缀合泛素部分与 与靶蛋白具有高亲和力的分子。对于一个证明或概念，肽将首先被用作亲和力 分子。这种原型因此被称为亲和肽缀合泛素（APCU）。在我们的初步研究中， 我们设计了一个原型APCU分子，它带有一个靶向MCL 1的肽，MCL 1是一种过度表达的癌蛋白， 在许多类型的癌症中。我们发现，这种分子可以特异性地降低MCL 1蛋白的水平， 促进其退化。在本研究中，我们将确定APCU的作用机制 设计此类分子的方法和最佳条件。我们还将确定剂量 MCL 1靶向APCU的响应曲线及其去泛素化系统的敏感性。进而 为广泛使用和未来的体内应用做准备，我们将在其他几个方面测试APCU的应用。 蛋白质，并探索用条件缀合策略形成APCU分子的可行性。这 这项研究如果成功，将提供一种非常有价值的工具，专门降解蛋白质， 研究和潜在的治疗用途。

Targeted degradation of proteins by affinity peptide conjugated ubiquitin (APCU) Protein degradation possesses many unique properties that cannot be covered by DNA/RNA manipulation tools. To understand the mechanism of biological processes, and to achieve desirable therapeutic effects, techniques designed to induce protein degradation are in critical needs. However, very few options are currently available for such purposes. Also, the existing tools have known limitations such as difficulty for adaptation or bell-shaped dose-response curve, or vulnerability for a negative regulation by the de- ubiquitination system. To expand the option for tools, and to overcome limitations of current methods, we propose to establish a new approach to induce protein degradation by conjugating a ubiquitin moiety with a molecule of high affinity to a target protein. For a proof or concept, peptides will first be used as the affinity molecule. This prototype is thus called affinity peptide conjugated ubiquitin (APCU). In our preliminary study, we designed a prototype APCU molecule with a peptide targeting MCL1, an oncoprotein that is over-expressed in many types of cancer. We found that this molecule can specifically reduce the level of MCL1 protein by promoting its degradation. In the proposed study, we will determine the action mechanism of the APCU approach and the optimal conditions for designing this types of molecules. We will also determine the dose response curve of the MCL1-targeting APCU and its sensitivity of de-ubiquitination system. Furthermore, to prepare for a wide usage and future in vivo applications, we will test the application of APCU on several other proteins and explore the feasibility of forming an APCU molecule with a conditional conjugation strategy. This proposed study, if secedes, will provide a highly valuable tool to specifically degrade a protein for mechanistic investigations and for potential therapeutic usages.