Center for Molecular Parasitology, Institute for Molecular Medicine and Infectious Disease, Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, United States of America.
Department of Biochemistry and Molecular Biology, The Huck Center for Malaria Research, Pennsylvania State University, University Park, Pennsylvania, United States of America.
PLoS One. 2022 Aug 19;17(8):e0273357. doi: 10.1371/journal.pone.0273357. eCollection 2022.
Despite ongoing efforts to control malaria infection, progress in lowering the number of deaths and infections appears to have stalled. The continued high incidence of malaria infection and mortality is in part due to emergence of parasites resistant to frontline antimalarials. This highlights the need for continued identification of novel protein drug targets. Mitochondrial functions in Plasmodium falciparum, the deadliest species of human malaria parasite, are targets of validated antimalarials including atovaquone and proguanil (Malarone). Thus, there has been great interest in identifying other essential mitochondrial proteins as candidates for novel drug targets. Garnering an increased understanding of the proteomic landscape inside the P. falciparum mitochondrion will also allow us to learn about the basic biology housed within this unique organelle. We employed a proximity biotinylation technique and mass spectrometry to identify novel P. falciparum proteins putatively targeted to the mitochondrion. We fused the leader sequence of a mitochondrially targeted chaperone, Hsp60, to the promiscuous biotin ligase TurboID. Through these experiments, we generated a list of 122 "putative mitochondrial" proteins. To verify whether these proteins were indeed mitochondrial, we chose five candidate proteins of interest for localization studies using ectopic expression and tagging of each full-length protein. This allowed us to localize four candidate proteins of unknown function to the mitochondrion, three of which have previously been assessed to be essential. We suggest that phenotypic characterization of these and other proteins from this list of 122 could be fruitful in understanding the basic mitochondrial biology of these parasites and aid antimalarial drug discovery efforts.
尽管一直在努力控制疟疾感染，但降低死亡和感染人数的进展似乎已经停滞。疟疾感染和死亡率持续居高不下的部分原因是寄生虫对一线抗疟药物产生了耐药性。这突出表明需要继续确定新的蛋白质药物靶点。恶性疟原虫（恶性疟原虫）的线粒体功能是已验证的抗疟药物的靶点，包括阿托伐醌和丙氨嘧啶（Malarone）。因此，人们一直对鉴定其他必需的线粒体蛋白作为新的药物靶点很感兴趣。增加对恶性疟原虫线粒体内部蛋白质组景观的了解，也将使我们能够了解这个独特细胞器内的基本生物学。我们采用了一种邻近生物素化技术和质谱法来鉴定新的恶性疟原虫蛋白，这些蛋白可能靶向线粒体。我们将一个靶向线粒体的伴侣蛋白 Hsp60 的前导序列与广谱生物素连接酶 TurboID 融合。通过这些实验，我们生成了一份 122 种“假定线粒体”蛋白的列表。为了验证这些蛋白是否确实是线粒体蛋白，我们选择了五个感兴趣的候选蛋白进行异位表达和全长蛋白的标记定位研究。这使我们能够将四个未知功能的候选蛋白定位到线粒体，其中三个以前被评估为必需的。我们认为，对这些蛋白和该列表中的其他蛋白进行表型特征分析可能有助于理解这些寄生虫的基本线粒体生物学，并有助于抗疟药物的发现工作。
