Regulation and Function of SUMO Protein Modification

项目总结 小泛素相关修饰物(SUMO)起翻译后蛋白质修饰的作用，从而 调节几乎所有必要的细胞功能。因此，相思甲基化与多种人类疾病有关， 包括癌症和神经退行性疾病，人们对相扑通路的靶向非常感兴趣 用于治疗目的。值得注意的是，相扑抑制剂的第一阶段临床试验最近被批准用于 癌症治疗。更详细地了解调节相思甲基化的基本分子机制及其 然而，为了充分发挥这些努力的潜力，需要对细胞功能产生影响。特别是，一个 针对相扑路径特定分支的能力可以实现更精确的治疗。脊椎动物 表达多个相扑并行，这可能允许如此精确的目标。然而，独特的 相扑对偶的性质和功能仍然知之甚少。为了解决这一知识差距，我们 正在利用最近开发的SUMO1和SUMO2基因敲除细胞系来定义和表征 这两个类似物的特定功能和分子作用机制。我们建议的目标包括： (1)我们将获得对SUMO1和SUMO2作为指定指定的唯一信号的假设的支持 与蛋白质结合后的独特命运。这将通过对特定于Paralog的 我们在SUMO1和SUMO2基因敲除细胞系中发现的表型，包括细胞的变化 形态、蛋白平衡缺陷和对细胞应激的超敏。(2)我们将检验多个假设，以 揭示了SUMO1和SUMO2非冗余功能的分子基础。关于这一点的假设 将探索与效应蛋白的链形成和选择性非共价相互作用的功能 通过使用一组SUMO1和SUMO2突变蛋白挽救敲除细胞表型。(3)我们会 测试在SUMO1和SUMO2基因敲除细胞系中观察到的表型变化是由于 部分与Paralog对基因表达的特异性影响有关。我们的研究结果将提供明确的证据 有关SUMO1和SUMO2 Paralog特定函数以及针对特定分支所需的重要见解，请参阅 用于治疗目的的相扑路径。

PROJECT SUMMARY Small ubiquitin related modifiers (SUMOs) function as posttranslational protein modifications and thereby regulate nearly all essential cell functions. As such, sumoylation is linked to a variety of human diseases, including cancer and neurodegenerative disorders, and there is great interest in targeting the SUMO pathway for therapeutic purposes. Notably, the first phase I clinical trial of a SUMO inhibitor was recently approved for cancer therapy. A more detailed understanding of basic molecular mechanisms regulating sumoylation and its consequences on cell function, however, is needed to achieve the full potential of these efforts. In particular, an ability to target specific branches of the SUMO pathway could allow for more precise therapies. Vertebrates express multiple SUMO paralogs which could allow for such precision targeting. However, the unique properties and functions of SUMO paralogs remain poorly understood. To address this gap in knowledge, we are taking advantage of recently developed SUMO1 and SUMO2 knockout cell lines to define and characterize the specific functions and molecular mechanisms of action of these two paralogs. Aims of our proposal include: (1) We will obtain support for the hypothesis that SUMO1 and SUMO2 function as unique signals specifying unique fates upon conjugation to proteins. This will be achieved through characterization of paralog-specific phenotypes we have identified in SUMO1 and SUMO2 knockout cell lines, including changes in cell morphology, defects in proteostasis and hypersensitivities to cell stress. (2) We will test multiple hypotheses to reveal the molecular basis for non-redundant functions of SUMO1 and SUMO2. Hypotheses concerning the function of chain formation and selective non-covalent interactions with effector proteins will be explored through rescue of knockout cell phenotypes using a panel of SUMO1 and SUMO2 mutant proteins. (3) We will test the hypothesis that phenotypic changes observed in SUMO1 and SUMO2 knockout cell lines are due in part to paralog-specific effects on gene expression. Results from our studies will provide unequivocal evidence for SUMO1 and SUMO2 paralog-specific functions and vital insights required to target specific branches of the SUMO pathway for therapeutic purposes.