Functional investigation of a novel and essential subcellular compartment in Plasmodium falciparum transmission stage parasites

项目摘要 疟疾是全世界疾病和死亡的一个重要原因，其中大多数死亡是由于 恶性疟原虫感染。成功完成恶性疟原虫生命周期和感染 新的人类宿主需要传播在人类红细胞的无性血阶段， 寄生虫群体分化成称为配子体的传播形式。这些配子母细胞 可以在被蚊子摄取后完成寄生虫生命周期的有性阶段。配子体 人红细胞的成熟发生在10-12天内， 细胞形态和硬度。一种新发现的蛋白PfBLEB（用于基底-侧向扩展边界） 是成熟配子体形成所必需的。在无性寄生虫中，PfBLEB是基底复合体的一部分， 在内膜复合物的前缘处的环状多蛋白复合物。虽然PfBLEB是 在配子体发育过程中，它是配子体发育所必需的， 发展PfBLEB敲除或敲除的配子母细胞在成熟过程中停滞，并且是非嵌合的。 传染的此外，PfBLEB缺陷配子母细胞具有大体形态学变化， 成熟的传播阶段寄生虫的主要细胞骨架特征的缺陷，包括内部 膜复合体和膜下微管。 在具有正常PfBLEB表达的配子母细胞中，PfBLEB定义了一个新的亚细胞区室， 寄生虫，划分寄生虫质膜的区域，这些区域缺乏下面的内 膜复合体PfBLEB区室对于配子母细胞发育是必需的，但其功能是 这种新发现的亚细胞区室的蛋白质成分仍然未知。的目标 目前的应用是确定和遗传学评价PfBLEB区室的蛋白质组分 并了解PfBLEB缺陷配子母细胞的功能缺陷。第一个目标将利用接近 标记和反向遗传学以探索含有PfBLEB的隔室。第二个目标是利用 多种成像和微加工技术，以获得什么过程是功能性的理解， PfBLEB缺陷型配子母细胞异常。总之，拟议的研究将为我们的 恶性疟原虫配子体发育的分子学研究

PROJECT SUMMARY Malaria is an important cause of illness and death worldwide, with most of these deaths resulting from Plasmodium falciparum infection. Successful completion of the P. falciparum life cycle and infection of a new human host requires transmission. During the asexual blood stage in human red blood cells, a small population of parasites differentiates into transmission forms known as gametocytes. These gametocytes can complete the sexual stage of the parasite life cycle following ingestion by a mosquito. Gametocyte maturation in human red blood cells occurs over 10-12 days and is associated with major changes in cellular morphology and rigidity. A newly discovered protein PfBLEB (for Baso-Lateral Expansion Boundary) is essential for mature gametocyte formation. In asexual parasites, PfBLEB is part of the basal complex, a ring-like multi-protein complex at the leading edge of the inner membrane complex. While PfBLEB is dispensable for both asexual replication and gametocyte commitment, it is essential for gametocyte development. PfBLEB-knockdown or knockout gametocytes arrest during maturation and are non- transmissible. Furthermore, the PfBLEB-deficient gametocytes have gross morphologic changes with defects in major cytoskeletal features of the maturing transmission-stage parasite, including the inner membrane complex and subpellicular microtubules. In gametocytes with normal PfBLEB expression, PfBLEB defines a new subcellular compartment within the parasite, demarcating the regions of the parasite plasma membrane that are devoid of the underlying inner membrane complex. The PfBLEB-compartment is essential for gametocyte development, but the function and protein constituents of this newly discovered subcellular compartment remain unknown. The goal of the current application is to define and genetically evaluate the protein components of the PfBLEB compartment and to understand the functional defects in PfBLEB-deficient gametocytes. The first aim will utilize proximity labeling and reverse genetics to explore the PfBLEB-containing compartment. The second aim will utilize multiple imaging and microfabrication techniques to gain a functional understanding of what processes are abnormal in PfBLEB-deficient gametocytes. Together, the proposed studies will add a new layer to our molecular understanding of gametocyte development in P. falciparum.