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

项目总结 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 恶性疟原虫感染。成功完成恶性疟原虫生活史和感染 新的人类宿主需要传播。在人类红细胞的无性血液阶段，一小部分 寄生虫种群分化为称为配子体的传播形式。这些配子体 在被蚊子摄取后，可以完成寄生虫生活史的有性阶段。配子体 人类红细胞的成熟发生在10-12天，并与以下主要变化有关 细胞形态和硬度。一种新发现的蛋白质PfBLEB(基底-侧向扩展边界) 是形成成熟配子体所必需的。在无性寄生虫中，PfBLEB是基础复合体的一部分，a 位于内膜复合体前沿的环状多蛋白复合体。而PfBLEB是 对于无性复制和配子体承诺来说都是必不可少的，对配子体是必不可少的 发展。PfBLEB-基因敲除或基因敲除配子体在成熟过程中停滞，是非 可传染的。此外，PfBLEB缺陷的配子体具有大体的形态变化。 成熟传播期寄生虫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PfBLEB表达正常的配子体中，PfBLEB定义了一个新的亚细胞室 寄生虫，划分寄生虫质膜上没有底层内膜的区域 膜复合体。PfBLEB隔室是配子体发育所必需的，但其功能 这个新发现的亚细胞室的蛋白质成分尚不清楚。的目标是 目前的应用是定义和遗传评估PfBLEB隔室的蛋白质成分 了解PfBLEB基因缺陷配子体的功能缺陷。第一个目标将利用邻近 标记和反向遗传学以探索含有PfBLEB的隔室。第二个目标将利用 多种成像和微制造技术，以从功能上了解什么是工艺 PfBLEB缺陷配子体异常。综上所述，拟议的研究将为我们的 恶性疟原虫配子体发育的分子理解。

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.