Regulation and Function of SUMO-1 Protein Modification

描述（由申请人提供）：SUMO（小泛素相关修饰物）是约100个氨基酸的蛋白质，其与数百种其他蛋白质共价后结合，从而调节广泛的细胞过程。我们已经发现，类小泛素化，如泛素化和磷酸化，是一个重要的调节器的有丝分裂在哺乳动物细胞。哺乳动物表达三种SUMO旁系同源物：SUMO-1、SUMO-2和SUMO-3（因为SUMO-2和SUMO-3 96%相同，所以它们被称为SUMO-2/3）。我们的研究结果表明，SUMO-1和SUMO-2/3在有丝分裂过程中与独特的蛋白质亚群结合，并且它们调节不同的过程。然而，仍然存在许多未解之谜。SUMO-1和SUMO-2/3修饰的许多相关靶标仍有待鉴定和表征，并且在有丝分裂中调节其时间修饰的机制尚不清楚。此外，SUMO-1和SUMO-2/3修饰对其靶点的特定分子效应，以及这些效应如何促进有丝分裂的进展，仍然知之甚少。在这个更新补助金申请中提出的研究目标是解决这些问题，并发展一个详细的分子理解sumoylation如何影响有丝分裂的进展。这些目标将通过四个具体目标来实现：（1）我们将定义SUMO-2/3修饰和结合在有丝分裂期间着丝粒相关蛋白的靶向和组装中发挥的作用。(2)我们将确定和表征在有丝分裂过程中调节蛋白质的时间和空间SUMO化的分子机制。(3)我们将确定和表征染色体相关蛋白sumoylated在后期和末期。(4)我们将研究多聚SUMO-2/3链和有丝分裂相关链结合蛋白的生物物理性质和功能。

DESCRIPTION (provided by applicant): SUMOs (small ubiquitin-related modifiers) are ~100 amino acid proteins that are posttranslationally and covalently conjugated to hundreds of other proteins and thereby regulate a wide range of cellular processes. We have found that sumoylation, like ubiquitination and phosphorylation, is an essential regulator of mitosis in mammalian cells. Mammals express three SUMO paralogs: SUMO-1, SUMO-2 and SUMO-3 (because SUMO-2 and SUMO-3 are 96% identical, they are referred to as SUMO-2/3). Our findings indicate that SUMO-1 and SUMO-2/3 are conjugated to unique subsets of proteins during mitosis and that they regulate distinct processes. However, many unanswered questions still exist. Many of the relevant targets of SUMO-1 and SUMO-2/3 modification remain to be identified and characterized, and mechanisms regulating their temporal modification in mitosis are not known. In addition, the specific molecular effects of SUMO-1 and SUMO-2/3 modification on their targets, and how these effects facilitate progression through mitosis, are still poorly understood. The goals of the research proposed in this renewal grant application are to address these questions and develop a detailed molecular understanding of how sumoylation affects progression through mitosis. These goals will be achieved through four specific aims: (1) We will define the roles that SUMO-2/3 modification and binding play in the targeting and assembly of kinetochore-associated proteins during mitosis. (2) We will identify and characterize molecular mechanisms regulating the temporal and spatial sumoylation of proteins during mitosis. (3) We will identify and characterize chromosome-associated proteins sumoylated during anaphase and telophase. (4) We will investigate the biophysical properties and functions of polymeric SUMO-2/3 chains and mitosis-related chain-binding proteins.