Functional characterization of the main integral protein components of the parasite-host cell interface of Plasmodium falciparum blood stages

人类疟疾寄生虫恶性疟原虫在红细胞中的细胞内发育是疟疾临床症状的原因。在红细胞中，寄生虫通过一层被称为寄生液泡膜（PVM）的膜与宿主细胞质分离。这种膜在寄生虫与宿主细胞的相互作用中起着关键作用，但其许多功能尚不清楚或未知。PVM含有短的、高电荷的和高度丰富的完整膜蛋白，称为EXP1和etramp（一个由14个蛋白组成的家族）。这些分子是迄今为止唯一已知的连接这层膜的蛋白质（它们包含一个延伸到宿主细胞和一个面向寄生虫的区域）。包括EXP1在内的一些基因对寄生虫的生存至关重要，它们可能在寄生虫与宿主细胞的相互作用中发挥关键作用。然而，由于技术限制，迄今尚未在恶性疟原虫中对它们进行功能分析。使用新技术，我们生成了EXP1的条件敲出。在这里，我们建议使用该技术来研究EXP1，并使用相同的技术来功能分析etramp。此外，我们开发了一种新的改进的接近生物素化方法来鉴定相互作用伙伴和室蛋白组，我们建议使用这些蛋白质组来鉴定与EXP1和etramp的宿主细胞面向结构域相互作用的因子。这也将产生其他方法难以获得的PVM外表面的蛋白质组。我们希望这项工作能够揭示寄生虫宿主细胞界面的主要组成部分的功能，并有助于理解寄生虫如何利用宿主红细胞并与宿主红细胞相互作用。

The intracellular development of the human malaria parasite Plasmodium falciparum in red blood cells is responsible for the clinical symptoms of malaria. In the red blood cell, the parasite is separated from the host cell cytosol by a membrane called the parasitophorous vacuolar membrane (PVM). This membrane plays a key role in the interaction of the parasite with its host cell but many of its functions are poorly understood or unknown. The PVM contains short, highly charged and highly abundant integral membrane proteins termed EXP1 and ETRAMPs (a family of 14 proteins). These molecules are the only so far known proteins bridging this membrane (they contain a domain reaching into the host cell and one facing the parasite). Several, including EXP1, are indicated to be essential for parasite survival and they likely play critical roles in the interaction of the parasite with the host cell. However, due to technical limitations, they have so far not been functionally analysed in P. falciparum parasites. Using new technology we generated a conditional knock out of EXP1. Here we propose to use this to study EXP1 and use the same technology to functionally analyse ETRAMPs. In addition we developed a new modified proximity biotinylation method to identify interaction partners and compartment proteomes that we propose to use to identify factors interacting with the host cell facing domain of EXP1 and ETRAMPs. This will also generate a proteome of the outer face of the PVM that with other means is difficult to obtain. We expect this work to unravel the function of the major integral components of the parasite host cell interface and to contribute to an understanding how the parasite exploits and interacts with the host red blood cell.