Elucidating the trafficking mechanisms of effector proteins to the Plasmodium infected red blood cell

阐明效应蛋白向疟原虫感染的红细胞的运输机制

• 批准号: 10319936
• 负责人: Vasant Muralidharan
• 金额: $ 37.5万
• 依托单位: UNIVERSITY OF GEORGIA
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-01-05 至 2023-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10319936
• 关键词: Affect; Antimalarials; Binding; Biochemical; Biological Assay; Biotin; Blood Vessels; Blood capillaries; Brain; Cell membrane; Cells; Cellular Membrane; Cessation of life; Clinical; Coagulation Process; Complex; Cytolysis; Cytoplasm; Data; Destinations; Disease; Drug Targeting; Drug resistance; Elements; Endoplasmic Reticulum; Endothelial Cells; Erythrocytes; Event; Flow Cytometry; Genes; Genetic; Glycine decarboxylase; Goals; Growth; Habitats; Heat-Shock Proteins 70; Home; Human; Immunofluorescence Microscopy; Infection; Label; Lead; Ligase; Lipids; Location; Malaria; Malaria Vaccines; Mass Spectrum Analysis; Measures; Membrane; Metabolism; Modeling; Molecular; Molecular Chaperones; Movement; Nutrient; Parasites; Parasitic Diseases; Pathway interactions; Peptide Signal Sequences; Permeability; Persons; Plasma Cells; Plasmodium; Plasmodium falciparum; Plastids; Process; Property; Protein Export Pathway; Protein Sortings; Proteins; Publishing; Research; Resistance; Resistance development; Role; Route; Signal Transduction; Site; Sorbitol; Sorting - Cell Movement; Sum; Testing; Time; Transmembrane Domain; Usher Proteins; Vacuole; Vesicle; base; conditional mutant; drug development; human disease; knock-down; member; mutant; novel; novel therapeutics; obligate intracellular parasite; plasmepsin; programs; protein transport; receptor; resistant strain; screening; secretory protein; trafficking; vesicle transport

Project Summary Plasmodium falciparum is a deadly human parasite that causes malaria and is responsible for nearly 450,000 deaths every year. Malaria is endemic in large regions of the world, home to about 4 billion people and it affects ~250 million people annually. There are no effective vaccines against malaria and antimalarial drugs are the mainstay of treatment. At this time, the parasite has gained resistance to all clinically available antimalarial drugs and these drug-resistant strains are spreading throughout the world, threatening all the progress that has been made against this disease in the last decade. Therefore, it is imperative that we constantly generate new drugs and identify potential drug targets to stay ahead of this nefarious disease. The clinical manifestations of this devastating parasitic disease, including death, are caused by the growth of P. falciparum within the host red blood cell (RBC). To build a suitable habitat for growth inside RBCs, the malaria parasite completely transforms the host cell. It changes the metabolism of the RBC, makes the RBC more rigid such that it is harder for the infected RBC to pass through capillaries, modifies the RBC membrane to allow for favorable movement of nutrients, and alters the binding properties of the RBC so that the infected cell can bind to the endothelial cells lining blood vessels. The sum of these changes leads to disease and death, for instance, binding of the P. falciparum infected RBC to endothelial cells can clog blood vessels in the brain leading to clots that eventually result in death. The subjugation of the infected RBC is accomplished through the action of several hundred proteins that the parasite transports to the host cell via poorly understood mechanisms. The export of parasite effector proteins is essential for transforming the RBC and therefore, for causing disease. Parasite effector proteins that are synthesized in the parasite cytoplasm need to be transported across three or four cellular membranes in order to reach their site of action in the host RBC. The molecular mechanisms that recognize, sort, and transport these parasite effectors to the infected RBC remain to be identified. The proposed studies aim to unravel the molecular processes that govern key early events that set parasite effectors on the path to the host RBC. We will pursue two aims to accomplish this goal. First, we will generate conditional mutants of proteins in the endoplasmic reticulum of the parasite that are potentially required for export of parasite effectors. The mutants will be analyzed using genetic, cellular, and biochemical approaches to determine their roles in the export of parasite proteins. Second, we will take an unbiased interactome screening approach that uses a proximity-based labeling approach and discover proteins that usher exported proteins to their site of action in the host RBC. Attaining the objectives of the research program will reveal key and unique protein trafficking mechanisms of P. falciparum that may be targeted for antimalarial drug development.

项目摘要 恶性疟原虫是一种致命的人寄生虫，可引起疟疾，并造成近45万 每年死亡。疟疾在世界上大型地区是地方性的，有约40亿人口 每年影响约2.5亿人。没有针对疟疾和抗疟药的有效疫苗 是治疗的主要主体。目前，寄生虫对所有临床可用 抗疟药和这些耐药菌株正在世界各地蔓延，威胁所有 在过去十年中，对这种疾病取得的进展。因此，我们必须 不断产生新药并确定潜在的药物靶标，以保持这种邪恶疾病的领先地位。这 这种毁灭性寄生虫病（包括死亡）的临床表现是由P的生长引起的。 宿主红细胞（RBC）内的恶性疾病。为了在RBC内建立合适的栖息地，疟疾 寄生虫完全改变了宿主细胞。它改变了RBC的新陈代谢，使RBC更加僵化 因此，感染的RBC难以通过毛细血管，修饰RBC膜以允许 养分的有利运动，并改变RBC的结合特性，使感染细胞可以结合 到内皮细胞衬里血管。这些变化的总和导致疾病和死亡，因为 实例，恶性疟原虫感染的RBC与内皮细胞的结合会堵塞大脑中的血管 导致凝块最终导致死亡。感染RBC的征服是通过 寄生虫通过不理会的几百种蛋白质传递到宿主细胞的作用 机制。寄生虫效应蛋白的出口对于转化RBC至关重要，因此，对于 引起疾病。在寄生虫细胞质中合成的寄生虫效应蛋白需要为 在三个或四个细胞膜上运输，以便在宿主RBC中到达其作用部位。这 识别，分类和运输这些寄生虫效应子到感染的RBC的分子机制仍然存在 被识别。拟议的研究旨在阐明主导着重要早期事件的分子过程 将寄生虫效应子设置在通往主机RBC的路径上。我们将追求两个目标来实现这一目标。首先，我们 将产生寄生虫内质网中蛋白质的条件突变体 出口寄生虫效应子所需。将使用遗传，细胞和生化分析突变体 确定它们在寄生虫蛋白出口中作用的方法。其次，我们将采取公正 使用基于接近度的标签方法并发现蛋白质的Interactome筛选方法 将蛋白质出口到主机RBC的作用部位。达到研究计划的目标 将揭示可能针对抗疟疾的恶性疟原虫的关键和独特的蛋白质运输机制 药物开发。