High throughput structure/function analysis of SUMO modification

sumo（小泛素相关修饰因子）是翻译后与其他蛋白质结合的蛋白质，从而调节对正常细胞生长、分化和存活至关重要的广泛基本功能。值得注意的是，sumoylation与多种人类疾病的发生和进展直接相关，包括神经变性、中风、心脏病、唇腭裂和癌症。在过去的十年中，在阐明sumo与靶蛋白结合的分子机制和识别由sumo化调节的细胞过程方面取得了巨大进展。尽管有这些见解，然而，关于sumoylation如何在分子水平上影响修饰蛋白，以及这些影响如何转化为细胞功能控制的基本问题仍有待解决。在许多情况下，sumoylation对靶蛋白的影响仍然未知。此外，sumoylation如何能够在与不同蛋白质结合时引发独特的命运也知之甚少。我们将使用出芽酵母，酿酒酵母，作为一个模式生物来研究sumoylation的基本功能。拟议研究的目标是开发一个高分辨率的相扑结构/功能图。这一目标将通过合成酵母SUMO突变体的综合文库和使用各种旨在探索SUMO结构/功能关系的生物化学和遗传学分析来表征这些突变体来实现。利用这个文库，我们将验证SUMO代表一个多功能和可变信号的假设，该信号具有不同的表面残基，影响与不同调节因子和下游SUMO结合蛋白的相互作用。我们还将测试一个假设，即summoylation以一种类似伴侣的能力起作用，以保护蛋白质免受细胞毒性细胞应激效应引起的损伤和聚集。

DESCRIPTION (provided by applicant): PROJECT SUMMARY SUMOs (small ubiquitin-related modifiers) are proteins that are posttranslationally conjugated to other proteins, thereby regulating a wide range of essential functions critical for normal cell growth, differentiation and survival. Notably, sumoylation has been directly linked to the development and progression of a variety of human diseases, including neurodegeneration, stroke, heart disease, cleft lip/palate and cancer. During the past ten years enormous progress has been made in elucidating the molecular mechanisms involved in conjugating SUMOs to target proteins and in identifying the cellular processes regulated by sumoylation. Despite these insights, however, fundamental questions about how sumoylation actually affects modified proteins at the molecular level, and how these effects are translated into control of cell function, remain to be addressed. In many cases, the effects of sumoylation on target proteins remain unknown. In addition, how sumoylation is able to elicit unique fates upon conjugation to different proteins is also poorly understood. We will use the budding yeast, S. cerevisiae, as a model organism for studying the essential functions of sumoylation. A goal of the proposed studies is develop a high-resolution structure/function map of SUMO. This goal will be achieved through the synthesis of a comprehensive library of yeast SUMO mutants and characterization of these mutants using a variety of assays designed to probe SUMO structure/function relationships both biochemically and genetically. With this library, we will test the hypothesis that SUMO represents a versatile and variable signal with distinct surface residues affecting interactions with distinct regulatory factors and downstream SUMO-binding proteins. We will also test the hypothesis that sumoylation functions in a chaperone-like capacity to protect proteins from damage and aggregation caused by the effects of cytotoxic cell stresses.