Regulation and Function of SUMO Protein Modification

项目摘要 小泛素相关修饰物（SUMO）作为翻译后蛋白质修饰起作用， 几乎所有细胞的基本功能。因此，类小泛素化与多种人类疾病有关， 包括癌症和神经退行性疾病，人们对靶向SUMO通路非常感兴趣 用于治疗目的。值得注意的是，SUMO抑制剂的第一个I期临床试验最近被批准用于 癌症治疗更详细地了解调节sumoylation的基本分子机制及其 然而，要实现这些努力的全部潜力，就需要对细胞功能产生影响。尤其是 靶向SUMO通路的特定分支的能力可以允许更精确的治疗。脊椎动物 表达多个SUMO旁系同源物，这可以允许这样的精确靶向。然而，独特的 SUMO旁系同源物的性质和功能仍然知之甚少。为了填补这一知识空白，我们 正在利用最近开发的SUMO 1和SUMO 2敲除细胞系来定义和表征 这两种旁系同源物的具体功能和分子作用机制。我们建议的目的包括： (1)我们将获得支持的假设，SUMO 1和SUMO 2功能作为独特的信号，指定 与蛋白质结合后的独特命运。这将通过鉴定旁系同源特异性 我们已经在SUMO 1和SUMO 2敲除细胞系中鉴定了表型，包括细胞凋亡的变化。 形态学、蛋白质稳态缺陷和对细胞应激的超敏反应。(2)我们将测试多个假设， 揭示了SUMO 1和SUMO 2的非冗余功能的分子基础。有关的假设 将探索链形成的功能以及与效应蛋白的选择性非共价相互作用 通过使用一组SUMO 1和SUMO 2突变蛋白拯救敲除细胞表型。(3)我们将 检验SUMO 1和SUMO 2敲除细胞系中观察到的表型变化是由于 部分旁系特异性影响基因表达。我们的研究结果将提供明确的证据 SUMO1和SUMO2旁系同源特异性功能和针对特定分支所需的重要见解 SUMO通路用于治疗目的。

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.