Essential function of a putative glycosyltransferase in P. falciparum

恶性疟原虫中假定的糖基转移酶的基本功能

• 批准号: 10215886
• 负责人: Vasant Muralidharan
• 金额: $ 18.88万
• 依托单位: UNIVERSITY OF GEORGIA
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-04-05 至 2023-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10215886
• 关键词: Age; Agreement; Animal Model; Antigens; Antimalarials; Biochemical Genetics; Biological Assay; Biological Process; Biotinylation; Blood; Cell membrane; Cells; Cessation of life; Child; Clinic; Clinical; Communicable Diseases; Complement; Complex; Culicidae; Data; Daughter; Development; Disease; Drug resistance; Drug usage; Endoplasmic Reticulum; Enzymes; Erythrocytes; Exocytosis; Family; Flow Cytometry; Fucose; Fucosyltransferase; Genetic; Glucose; Growth; Heat shock proteins; Hepatocyte; Human; Infection; Life Cycle Stages; Ligands; Link; Lipids; Malaria; Malaria Vaccines; Mammalian Cell; Mass Spectrum Analysis; Membrane; Microscopy; Modification; Molecular Chaperones; Organism; Parasites; Parasitic infection; Pathway interactions; Peptide Hydrolases; Plasmodium; Plasmodium falciparum; Play; Polysaccharides; Post-Translational Protein Processing; Process; Proteins; Quality Control; Recombinants; Research; Resistance; Resistance development; Role; Secretor blood group alpha-2-fucosyltransferase; Sequence Homology; Signal Transduction; Surface; Surface Antigens; Testing; Thrombospondins; Vacuole; Vesicle; Work; apical membrane; asexual; attenuation; base; conditional mutant; druggable target; gene function; genetic approach; glycosylation; glycosyltransferase; human disease; inhibitor/antagonist; member; mutant; novel; obligate intracellular parasite; parasite genome; protein function; resistant strain; success; sugar; transmission process; vector; vector mosquito

Project Summary The lethal form of human malaria is caused by the intracellular parasite Plasmodium falciparum, which causes nearly 450,000 deaths every year. Infection by these parasites results in ~250 million infections each year. However, there are no effective vaccines against malaria and the parasite has gained resistance to all antimalarial drugs used in the clinic. Further, these drug-resistant strains are spreading throughout the world. Therefore, it is crucial to identify essential druggable pathways used by the parasite to grow within human host cells. One such poorly understood but essential pathway is the modification of parasite proteins by sugar molecules or glycans. In other model organisms, this process is essential for protein function and mostly occurs in the secretory pathway. Recent work in Plasmodium parasites has shown that glycan modification of several parasite surface ligands play an essential role in parasite transmission and its development within the mosquito vector. But little is known about the function, if any, of glycosylation during the clinically important intraerythrocytic growth of P. falciparum. We recently identified a putative glycosyltransferase as an essential interactor of a heat shock protein residing in the endoplasmic reticulum. To study its function during the intraerythrocytic stages of parasite growth, we generated conditional mutants for this protein. We hypothesize that the glycosyltransferase function of this protein plays an essential function during intraerythrocytic growth of P. falciparum. Our preliminary data show that this protein is essential for parasite growth within human red blood cells and is required for the egress of daughter parasites from the host cell at the end of the intraerythrocytic life cycle. Using cellular, biochemical, and genetic approaches, we will define the function of this gene during egress of daughter parasites. The essentiality of the putative glycosyltransferase activity for parasite survival will be tested. The proposed studies will use recombinant enzyme to define the enzymatic activity of this glycosyltransferase. Proximity-dependent biotinylation approaches combined with mass spectrometry will be used to identify interactors as well as putative substrates. The success of this project will reveal novel and essential glycosylation pathways used by the parasite for asexual expansion in human red blood cells.

项目摘要 人类疟疾的致命形式是由恶性疟原虫的细胞内寄生虫疟原虫引起的 每年造成近450,000人死亡。这些寄生虫感染导致约2.5亿感染 每年。但是，没有针对疟疾的有效疫苗，寄生虫已经获得 对诊所中使用的所有抗疟药的耐药性。此外，这些耐药菌株正在扩散 全世界。因此，至关重要的是识别寄生虫使用的必需毒品途径 在人类宿主细胞内生长。一个如此鲜为人知但必不可少的途径是修改 糖分子或聚糖的寄生虫蛋白。在其他模型生物中，此过程至关重要 对于蛋白质功能，主要发生在分泌途径中。疟原虫寄生虫的最新工作 已经表明，几种寄生虫表面配体的聚糖修饰在寄生虫中起着至关重要的作用 传播及其在蚊子载体中的发展。但是对功能（如果有）知之甚少 恶性疟原虫的临床重要肠内生长期间的糖基化。我们最近 确定假定的糖基转移酶是位于热激蛋白的必不可少的相互作用者 内质网。为了研究其在寄生虫生长的关节内阶段的功能，我们 该蛋白质产生的条件突变体。我们假设糖基转移酶的功能 该蛋白在恶性疟原虫的肠内生长期间起着重要的功能。我们的初步 数据表明，该蛋白对于人类红细胞内的寄生虫生长至关重要，需要 对于肠内生命周期结束时从宿主细胞中的女儿寄生虫出口。使用 细胞，生化和遗传方法，我们将定义该基因在出口期间的功能 女儿寄生虫。假定的糖基转移酶活性对寄生虫存活的本质将会 进行测试。拟议的研究将使用重组酶来定义此的酶活性 糖基转移酶。接近依赖性生物素化方法与质谱法结合 将用于识别交互式和推定的底物。这个项目的成功将揭示 寄生虫使用的新颖和必需的糖基化途径用于人类红色的无性扩张 血细胞。