Nonconventional mitochondrial ribosomes of malaria parasites

疟疾寄生虫的非常规线粒体核糖体 项目总结 这个项目的总体目标是研究线粒体核糖体的结构和功能。 (有丝分裂体)在恶性疟原虫中。核糖体是一种大分子 由RNA和蛋白质组成的复合体(~2-丙二醛)，将基因组信息翻译成蛋白质。蛋白 翻译是所有生命形式中最基本、最关键的生物学过程。在疟疾寄生虫中，显然有 三个蛋白质翻译系统负责翻译细胞核、质外体和 线粒体。恶性疟原虫有丝分裂体在系统发育和结构上是高度分化的亲缘关系 对人类宿主的胞浆和线粒体核糖体的影响，这表明寄生虫的有丝分裂体可能 证明是一种有效的抗疟疾药物靶点。本提案中的研究将剖析其中的组成部分 并研究这台机器的生物学功能。因此，这一项目将有助于了解该结构 并扩展我们对核糖体RNA的了解 (RRNA)的功能和蛋白质的合成。此外，这项研究将为发现 以线粒体蛋白翻译为靶点的新型抗疟药。 疟疾寄生虫的线粒体是其复杂生命周期中必不可少的细胞器。它是 负责几个关键的生物合成途径，如嘧啶的生物合成和铁-硫簇 生物发生，似乎是昆虫通过氧化磷酸化产生能量所必需的 各阶段。维持线粒体电子传输链(MtETC)和膜电位是 对疟疾寄生虫来说是绝对必要的，而mtETC的细胞色素bc1复合体是一种已证实的 抗疟疾药物靶标。然而，我们仍然很大程度上对 寄生虫有丝分裂体，翻译细胞色素b和细胞色素c氧化酶的两个亚基。 疟疾寄生虫的线粒体dna(Mtdna)是最小的细胞器基因组，仅编码 MtETC的三个组分和~30个片段的rRNA基因片段。经济发展的间断性 RRNA基因和tRNA基因在基因组中的完全缺失使人们对 蛋白质翻译在这个细胞器中存在已有多年。 为了解决疟疾有丝分裂染色体的基本问题，我的第一个目标是剖析蛋白质亚基。 通过核糖体分离和质谱学相结合的方法对这一机器进行分析。其中的rRNA含量 丝裂原核糖体具有高通量、小RNA序列的特点。第二个目标是证明 寄生虫的有丝分裂是有功能的，也是必不可少的。将进行击倒和击倒研究 三个保守的核糖体蛋白亚基。这项研究将提供信息来填补一项重要的科学空白 并为未来的治疗干预提供了独特的机会。

Nonconventional mitochondrial ribosomes of malaria parasites Project summary The overall goal of this project is to investigate the structure and function of the mitochondrial ribosome (mitoribosome) in Plasmodium falciparum malaria parasites. The ribosome is a large-molecular-weight complex (~2 MDa) composed of RNAs and proteins that translates genomic information into proteins. Protein translation is a basic and pivotal biological process in all life forms. In malaria parasites, there are evidently three protein translation systems responsible for translating the genomes of the nucleus, the apicoplast and the mitochondrion. The mitoribosome in P. falciparum is phylogenetically and structurally highly divergent relative to the cytosolic and mitochondrial ribosomes of the human host, suggesting the parasite mitoribosome may prove to be an efficacious antimalarial drug target. The research in this proposal will dissect the components and investigate the biological functions of this machinery. Thus, this project would shed light on the structure and function of the ancient protein translational apparatus and expand our knowledge about ribosomal RNA (rRNA) function and protein synthesis in general. Moreover, this study would provide a basis for discovering novel antimalarial inhibitors targeting the mitochondrial protein translation. The mitochondrion of malaria parasites is an essential organelle throughout their complex lifecycle. It is responsible for several critical biosynthetic pathways, such as pyrimidine biosynthesis and iron-sulfur cluster biogenesis, and appears to be essential for energy production through oxidative phosphorylation in insect stages. Maintaining the mitochondrial electron transport chain (mtETC) and the membrane potential is absolutely essential for malaria parasites, and the cytochrome bc1 complex of the mtETC is a proven antimalarial drug target. However, we remain largely ignorant of the structure and function of the parasite mitoribosome, which translates cytochrome b and two subunits of the cytochrome c oxidase. The 6 kb mitochondrial DNA (mtDNA) in malaria parasites is the smallest organellar genome, only encoding three components of the mtETC and ~30 small pieces of fragmented rRNA genes. The discontinuity of the rRNA genes and the complete absence of tRNA genes in the genome have created some doubt regarding the existence of protein translation in this organelle for many years. To address the fundamental questions of malarial mitoribosome, my first aim is to dissect the protein subunits of this machinery through the combination of ribosome isolation and mass spectrometry. The rRNA content in mitoribosome will be characterized by high throughput small RNA-seq. The second aim is to prove that the parasite mitoribosome is functional and essential. Knockout and knock down studies will be carried out on three conserved ribosomal protein subunits. This study will provide information to fill an important scientific gap and offer unique opportunities for future therapeutic interventions.