The role of polo-like kinase in the duplication of the trypanosome cytoskeleton

 描述(申请人提供)：布氏锥虫是非洲锥虫病的人类病原体和牛的纳加纳病原体。可用于治疗锥虫病的少数有效治疗方法非常难以管理，而且耐药性是一个新出现的问题。目前正在研究的新药很少，这使得寻找治疗这种病原体的新方法成为当务之急。锥虫是高度极化的，有一个复杂的细胞骨架，将寄生虫的单个鞭毛定位在细胞的后部，并将其附着在CLL表面。这种排列对于适当的运动和完成细胞分裂是必要的。附着和定位鞭毛是锥虫细胞周期的基本特征，在哺乳动物中不是保守的，使这些过程成为药物干预的候选对象。我们已经鉴定出布鲁氏毛滴虫中的Polo样激酶同源物，称为TbPLK，是一系列细胞骨架细胞器遗传的重要调节因子，这些细胞器是定位和附着鞭毛所必需的。抑制或耗尽TbPLK会导致带有分离鞭毛的细胞无法进行有效的细胞分裂。这些严重的和不可逆转的缺陷使TbPLK成为一个有吸引力的药物靶点，并表明该激酶可能是锥虫形态发生的重要调节因子。确定底物和结合伙伴是理解TbPLK功能的关键下一步。这些新的蛋白质本身可能是可行的药物靶点。我们进行了三种不同的蛋白质组筛选来鉴定新的TbPLK相互作用子和底物，产生了74个候选。这项建议中的工作集中在表征这些蛋白质的功能，并确定它们在细胞周期过程中如何以及何时与TbPLK相互作用。我们的目标是利用这些新发现的蛋白质来建立TbPLK控制布鲁氏毛滴虫形态发生的分子基础。

 DESCRIPTION (provided by applicant): Trypanosoma brucei is the causative agent of African trypanosomiasis in humans and nagana in cattle. The few effective treatments available for treating trypanosomiasis are very difficult to administer and resistance is an emerging problem. Few new drugs are under investigation, which makes identifying novel treatments for this pathogen an urgent need. Trypanosomes are highly polarized and have a complex cytoskeleton that positions the parasite's single flagellum in the posterior of the cell and adheres it to the cll surface. This arrangement is necessary for proper motility and completion of cell division. Adhering and positioning the flagellum are essential features of the trypanosome cell cycle that are not conserved in mammals, making these processes attractive candidates for drug intervention. We have identified the polo-like kinase homolog in T. brucei, termed TbPLK, as an essential regulator of the inheritance of a series of cytoskeletal organelles that are essential fo positioning and adhering the flagellum. Inhibiting or depleting TbPLK leads to cells with detached flagella that cannot undergo productive cell divisions. These severe and irreversible defects make TbPLK an attractive drug target and suggest that the kinase may be an important regulator of morphogenesis in trypanosomes. Identifying substrates and binding partners is an essential next step to understanding TbPLK function. These novel proteins could themselves be viable drug targets. We conducted three different proteomic screens to identify novel TbPLK interactors and substrates, which yielded 74 candidates. The work in this proposal focuses on the characterizing the function of these proteins and determining how and when they interact with TbPLK during the course of the cell cycle. Our goal is to use these newly identified proteins to establish the molecular basis for TbPLK control of morphogenesis in T. brucei.