Erythrocyte Subversion by Malaria Parasite Exported Effectors

项目摘要/摘要 疟疾仍然是世界上最具破坏性的寄生虫病之一， 大多数死亡是由恶性疟原虫引起的。该病的病理结果 仅从感染的血液阶段开始，在此期间寄生虫入侵和繁殖 在宿主红细胞内。为了建立这种细胞内生态位，恶性疟原虫强加了惊人的 通过输出效应蛋白对红细胞进行修饰，但输出机制是 人们对寄生虫生存所必需的效应器功能知之甚少，但在很大程度上仍然存在 未知。出口到红血球需要穿过围绕在红细胞周围的液泡膜 寄生虫，依赖于出口的疟原虫易位子的易位事件 蛋白质(PTEX)。在最近的一篇论文中，候选人表明热休克蛋白的失活 101(HSP101)是PTEX的一个AAA+ATPase组分，导致蛋白质的完全阻断 出口和寄生虫死亡。相关的AAA+蛋白可以展开并定向穿透底物 提示HSP101可能推动效应蛋白的识别，并 为移位过程提供动力。拟议的职业发展计划旨在剖析 HSP101/PTEX在出口中的作用，并识别使寄生虫能够 在红血球内存活。具体目标1试图了解底物识别和 重组HSP101的催化特性及其在蛋白质输出中的作用 在完整的寄生虫体内。特定目标2将使用遗传和蛋白质组学方法来定义 其他PTEX组分的功能和一种交联质谱学方法 绘制建筑群的建筑地图。具体目标3将分析出口的功能 正向和反向效应在红细胞内寄生虫存活中的作用 遗传学以及蛋白质组学方法。PTEX是一种令人兴奋的新药靶点， 拟议的实验将揭示有关此出口角色的关键机械信息 机械作为合理设计药物的必要基础。此外，密钥的标识 出口在寄生虫存活中起作用的蛋白质可能会提供所需的额外治疗 目标。总的来说，这项工作将加深我们对疟疾寄生虫如何 颠覆其红细胞宿主细胞，支持疟疾控制新工具的开发 疾病。在此过程中获得的经验和研究工具将推动应聘者 以独立调查员的身份进入既定的职业生涯。

Project Summary/Abstract Malaria remains one of the most devastating parasitic diseases in the world with the vast majority of deaths caused by Plasmodium falciparum. The pathology of the disease results exclusively from the blood-stage of the infection during which parasites invade and multiply within host erythrocytes. To establish this intracellular niche, P. falciparum imposes striking modifications to the erythrocyte through export of effector proteins but the export mechanism is poorly understood and the effector functions essential to parasite survival remain largely unknown. Export into the red blood cell requires crossing a vacuole membrane surrounding the parasite, a translocation event that depends upon the Plasmodium translocon of exported proteins (PTEX). In a recent paper, the candidate showed that inactivation of heat shock protein 101 (HSP101), a AAA+ ATPase component of PTEX, results in a complete block in protein export and parasite death. Related AAA+ proteins can unfold and directionally thread substrates through a central channel, suggesting HSP101 may drive recognition of effector proteins and power the translocation process. The proposed career development plan aims to dissect the role of HSP101/PTEX in export and to identify key exported effectors that enable the parasite to survive within the erythrocyte. Specific Aim 1 seeks to understand the substrate recognition and catalytic properties of recombinant HSP101 and to dissect the role of HSP101 in protein export within intact parasites. Specific Aim 2 will use genetic and proteomic approaches to define the function of additional PTEX components and a cross-linking mass spectrometry approach to map the architecture of the complex. Specific Aim 3 will analyze the function of exported effectors implicated in parasite survival within the erythrocyte using forward and reverse genetics as well as proteomic approaches. PTEX is an exciting new drug target and the proposed experiments will reveal key mechanistic information about the role of this export machinery as a necessary basis for rational drug design. Furthermore, identification of key exported proteins with roles in parasite survival may provide needed additional therapeutic targets. Collectively, this work will further our understanding of how the malaria parasite subverts its erythrocyte host cell and support development of new tools for control of malaria disease. The experience and research tools acquired in the process will propel the candidate into an established career as an independent investigator.