Biochemical and Functional Analysis of Trypanin

描述（由申请人提供）：鞭毛原生动物寄生虫布鲁氏锥虫是导致非洲锥虫病的原因，该疾病在撒哈拉以南非洲地区导致人类和牲畜的广泛死亡和发病率。昏睡病如果不治疗是致命的，但目前还没有疫苗，目前的治疗方法陈旧、有毒且难以实施。因此，迫切需要进行研究以更好地了解这些寄生虫并促进新的治疗干预措施的发展。锥虫也是研究鞭毛和纤毛生物学的重要实验系统，对人体健康至关重要。布氏体依靠其鞭毛在宿主组织内运动并指导细胞发育和分裂。在真核生物的广泛研究表明，鞭毛除了在运动中具有典型的作用外，它还作为信号中心感知和响应环境中的外部信号。最近的研究表明，锥虫鞭毛同样具有运动和信号能力。这项工作的长期目标是确定运动性在发病机制中的作用，确定调节锥虫运动性的机制，并验证鞭毛指导对毒性重要的信号系统的假设。为此，我们将采用运动突变体，小鼠感染模型来测试信号和运动功能对感染的贡献。我们还将采用系统生物学方法来定义鞭毛中的信号系统，并确定由这些信号系统控制的基因。最后，我们将利用低温电子断层扫描，结合突变分析来建立鞭毛的三维分子模型，以了解锥虫鞭毛独特功能的结构基础。我们的重点是布氏体的鞭毛。然而，鞭毛对许多其他致病性原生动物以及正常的人类发育和健康都很重要。因此，我们希望我们的研究结果能够对寄生原生动物的发病机制、人类发育和生理以及真核生物的基础生物学的研究产生广泛的兴趣。

DESCRIPTION (provided by applicant): The flagellated protozoan parasite Trypanosoma brucei is responsible for African trypanosomiasis, which causes widespread mortality and morbidity of humans and livestock in sub-Saharan Africa. Sleeping sickness is fatal if untreated, yet no vaccine exists and current treatments are old, toxic and difficult to administer. Thus, ther is a pressing need for research to better understand these parasites and facilitate development of new therapeutic interventions. Trypanosomes are also an important experimental system for studying biology of flagella and cilia, which are critical to normal human health. T. brucei depends on its flagellum for movement within host tissues and for directing cell development and division. Extensive work in a wide range of eukaryotes demonstrates that in addition to the flagellum's canonical role in motility, it functions as a signaling center to perceive and respond o external cues in the environment. Recent work indicates that the trypanosome flagellum likewise functions in motility and signaling capacity. The long term goal of the proposed work is to determine the role of motility in pathogenesis, define mechanisms that regulate trypanosome motility and test the hypothesis that the flagellum directs signaling systems important for virulence. To do this, we will employ motility mutants, mouse infection models to test signaling and motility functions for a contribution to infection. We will also employ systems biology approaches to define signaling systems in the flagellum and identify genes controlled by these signaling systems. Finally, we will use cryoelectron tomography, together with mutational analysis to build a three-dimensional molecular model of the flagellum in an effort to understand structural foundations of unique flagellum functions in trypanosomes. Our focus is on the flagellum of T. brucei. However, flagella are important for many other pathogenic protozoa as well as for normal human development and health. Therefore, we expect our results to be of wide interest for the community studying pathogenesis of parasitic protozoa, human development and physiology, and fundamental biology of eukaryotes.