Exploiting bacterial effector proteins to study human ubiquitin signaling

项目摘要 翻译后信号通过泛素化对所有真核生物都是必不可少的，而这一过程的失调 这一过程可能会导致严重的疾病形式。泛素信号在许多领域的深远重要性 细胞过程源于其形成一组不同聚合链的能力，这些聚合链发出不同结果的信号。 泛素信号的复杂性远远超过了我们对其调控和细胞结果的理解。 虽然某些泛素链类型的信号作用是已知的(例如，蛋白质降解或细胞周期 监管)，许多所谓的“非典型”链的功能仍然是一个谜，尽管几十年来 研究。作为研究基础人类生物学的另一种方法，我们研究了 入侵病原菌和宿主泛素信号网络。除了一系列其他泛素- 靶向活动，支持感染细菌已经进化出分泌的效应蛋白来组装和移除 宿主泛素信号，在某些情况下具有对离散泛素链类型的精致特异性。我们建议 泛素靶向的细菌效应器代表了一个研究人类泛素信号的丰富机会 “由外而内”的观点。为了探索这个机会，我们开发了一种多管齐下的方法，已经 在重要的细菌病原体中鉴定新的泛素靶向活性。使用结构和 生化方法我们将解释这些细菌酶的机制和特异性，在那里 要点它们将被用作案例研究和工具，以扩展我们的工作，以破译监管和 人类泛素系统的信号复杂性。我们研究泛素生物学作用的创新方法 以我们在生化机制上的强项对其进行调控，并利用强大的进化压力 放在细菌身上，篡改宿主泛素信号的特定方面。在未来五年，我们将 展示细菌泛素靶向活性的广度及其对解剖错综复杂的 泛素信号，这有助于我们更大的视野来理解 细菌干扰宿主信号传递过程。

Project Summary Post-translational signaling through ubiquitination is essential to all eukaryotic life, and dysregulation of this process can lead to severe forms of disease. The far-reaching importance of ubiquitin signaling across many cellular processes stems from its ability to form a diverse set of polymeric chains that signal for distinct outcomes. The complexity of ubiquitin signaling vastly outweighs our understanding of its regulation and cellular outcomes. While the signaling roles for some ubiquitin chain types are known (e.g. protein degradation or cell cycle regulation), the functions of many so-called `atypical' chains have remained a mystery despite decades of research. As an alternative approach to studying fundamental human biology, we study the interactions between invading pathogenic bacteria and the host ubiquitin signaling network. In addition to a range of other ubiquitin- targeted activities, to support infection bacteria have evolved secreted effector proteins to assemble and remove host ubiquitin signals, in some cases with exquisite specificity toward discrete ubiquitin chain types. We propose that ubiquitin-targeted bacterial effectors represent a rich opportunity to study human ubiquitin signaling from an `outside-in' perspective. To explore this opportunity, we have developed a multipronged approach that has identified novel ubiquitin-targeted activities among important bacterial pathogens. Using structural and biochemical approaches we will explain the mechanisms and specificities of these bacterial enzymes, at which point they will be used as case studies and tools to extend our work toward deciphering the regulatory and signaling complexities of the human ubiquitin system. Our innovative approach to studying ubiquitin biology plays to our strengths in the biochemical mechanisms of its regulation, and leverages the strong evolutionary pressure placed on bacteria to usurp specific aspects of host ubiquitin signaling. Over the next five years we will demonstrate the breadth of bacterial ubiquitin-targeted activities and their utility for dissecting the intricacies of ubiquitin signaling, which feeds into our larger vision of understanding the motivations and ramifications of bacterial interference in host signaling processes.