Molecular mechanisms of schizogony in malaria parasites

疟原虫分裂的分子机制

• 批准号: 9797203
• 负责人: JEFFREY D DVORIN
• 金额: $ 61.72万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-06-01 至 2024-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9797203
• 关键词: 5 year old; Address; Alleles; Apical; Automobile Driving; Binding; Biochemical; Biogenesis; Biological; Biological Assay; Biological Process; Blood; Cell Nucleus; Cell membrane; Cell physiology; Cells; Centrosome; Cessation of life; Child; Chromosome Condensation; Clinical; Co-Immunoprecipitations; Complex; Cytokinesis; Cytoplasm; Data; Daughter; Defect; Development; Dynamin; Erythrocytes; Excision; Failure; Future; Genetic; Goals; Guanosine Triphosphate Phosphohydrolases; Human; Individual; Infection; Investigation; Knowledge; Label; Learning; Link; Lipid Bilayers; Malaria; Mediating; Membrane; Molecular; Morbidity - disease rate; Names; Organelles; Parasites; Pathway interactions; Plasmodium; Plasmodium falciparum; Process; Proteins; Public Health; Recombinant Proteins; Resolution; Role; Shapes; Site; Structure; System; Techniques; Testing; Therapeutic; Video Microscopy; Work; asexual; condensin; experimental study; improved; knock-down; molecular marker; mortality; mutant; novel; nuclear division; protein complex; protein protein interaction; recruit; reverse genetics

PROJECT SUMMARY Malaria is an important cause of illness and death worldwide, with most of these deaths resulting from Plasmodium falciparum infection. Clinical malaria results from the asexual replication of parasites in human red blood cells. During the blood stage, P. falciparum replicates via schizogony, wherein daughter parasites are formed by a specialized cytokinesis known as segmentation. The inner membrane complex (IMC), a unique structure within the parasite composed of parasite proteins and a double lipid bilayer that is closely associated with the plasma membrane, and associated basal complex are hypothesized to orchestrate daughter parasite assembly and division. The focus of the current application is on the molecular mechanisms of schizogony and segmentation. Directed experiments will determine the biogenesis, composition, and function of the IMC and basal complex. We have discovered two novel parasites that are essential for schizogony and segmentation. The first, PfMOP, localizes initially near the centrosome and later to the apical end of the parasite and is critical for IMC biogenesis. The second, PfCINCH, localizes to the basal complex and is critical for parasite cytokinesis. These two proteins allow interrogation of the IMC and basal complex from the apical and basal ends of the parasite, respectively. The recently discovered P. falciparum Merozoite Organizing Protein is essential for both asexual and gametocyte development. In PfMOP-deficient parasites, the IMC does not form properly, resulting in a failure of segmentation, and the incompletely segmented merozoites remain in an agglomerate with a common cytoplasm. The molecular function of PfMOP and its link to the progression of schizogony and IMC biogenesis remain unknown. The proposed studies address these critical knowledge gaps. The first aim is divided into three independent subaims. In Aim 1.1, the link between PfMOP and IMC biogenesis in late schizogony will be investigated using a cell biologic approach with live video microscopy. In Aim 1.2, the function of PfMOP in early schizonts will be investigated, testing the hypothesis that PfMOP recruits a critical protein complex for chromosome condensation. In Aim 1.3, the PfMOP protein interactions in late schizonts will be determined, validated, and functionally evaluated by reverse-genetics. PfCINCH (Coordinator of nascent cell detachment) is a novel and essential component of the basal complex. In PfCINCH-deficient parasites, the final stages of segmentation are disrupted. In the second aim of this proposal, we focus on the cellular function of PfCINCH and its protein-protein interactions. The long-term objectives and public health implications of these studies are to identify critical biologic process pathways in the malaria parasite that could be targeted by future therapeutics.

项目摘要 疟疾是全球疾病和死亡的重要原因，其中大多数死亡是由 恶性疟原虫感染。临床疟疾是由于人类寄生虫的无性复制而引起的 红细胞。在血液阶段，恶性疟原虫通过精神分裂复制，其中女儿寄生虫 由称为分割的专门细胞因子形成。内膜复合物（IMC）， 由寄生虫蛋白和双脂质双层组成的寄生虫内的独特结构 假设与质膜和相关的基底复合物相关 女儿寄生虫大会和部门。当前应用的重点是分子 精神分裂和分割的机制。定向实验将确定生物发生， IMC和基础复合物的组成和功能。我们发现了两个新颖的寄生虫 对于精神分裂和细分至关重要。首先是PFMOP，最初位于中心体附近 后来到寄生虫的顶端末端，对于IMC生物发生至关重要。第二个，pfcinch，本地化 基底复合物，对于寄生虫细胞因子至关重要。这两种蛋白质允许对IMC进行询问 分别来自寄生虫的顶端和基础末端的基础复合物。 最近发现的恶性疟原虫组织蛋白对于无性和 配子细胞开发。在缺乏PFMOP的寄生虫中，IMC不正确形成，导致 分割的失败和不完全分割的梅罗祖族保留在一个与A的团聚中 常见的细胞质。 PFMOP的分子功能及其与精神分裂和IMC的进展的链接 生物发生仍然未知。拟议的研究解决了这些关键的知识差距。第一个目的是 分为三个独立的subiaims。在AIM 1.1中，PFMOP与IMC生物发生之间的联系 将使用现场视频显微镜的细胞生物学方法对精神分析进行研究。在AIM 1.2中 将研究PFMOP在早期精神分子中的功能，检验PFMOP招募A的假设 染色体凝结的关键蛋白质复合物。在AIM 1.3中，PFMOP蛋白质的相互作用最近 Schizonts将通过反基因确定，验证和功能评估。 pfcinch （新生细胞脱离的协调员）是基底复合物的新颖且重要的组成部分。在 Pfcinch缺陷寄生虫，分割的最后阶段被破坏。在第二个目标中 提案，我们专注于PFCINCH及其蛋白质蛋白质相互作用的细胞功能。长期 这些研究的目标和公共卫生影响是确定关键的生物学过程途径 未来治疗药物可能针对的疟原虫。