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

基本信息

批准号：
10382321
负责人：
Vasant Muralidharan
金额：
$ 22.65万
依托单位：
UNIVERSITY OF GEORGIA
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-04-05 至 2024-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10382321
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 member mutant novel obligate intracellular parasite parasite genome protein function resistant strain success sugar transmission process vector vector mosquito

项目摘要

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.

项目概要人类疟疾的致命形式是由细胞内寄生虫恶性疟原虫引起的，每年造成近45万人死亡。这些寄生虫的感染导致约 2.5 亿人感染每年。然而，目前还没有针对疟疾的有效疫苗，而且疟原虫已经蔓延对临床上使用的所有抗疟药物产生耐药性。此外，这些耐药菌株正在蔓延全世界。因此，确定寄生虫使用的基本药物途径至关重要在人类宿主细胞内生长。一种人们知之甚少但必不可少的途径是修饰糖分子或聚糖对寄生虫蛋白质的影响。在其他模式生物中，这个过程是必不可少的对于蛋白质功能，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发挥着重要作用传播及其在蚊子媒介内的发展。但对该功能知之甚少，如果有的话，恶性疟原虫在临床上重要的红细胞内生长过程中的糖基化。我们最近确定了一种假定的糖基转移酶作为存在于热休克蛋白的重要相互作用物内质网。为了研究其在寄生虫生长的红细胞内阶段的功能，我们产生该蛋白质的条件突变体。我们推测糖基转移酶的功能该蛋白在恶性疟原虫红细胞内生长过程中发挥着重要作用。我们的初步数据表明，这种蛋白质对于人体红细胞内寄生虫的生长至关重要，并且是必需的用于在红细胞内生命周期结束时子代寄生虫从宿主细胞中排出。使用细胞、生物化学和遗传方法，我们将定义该基因在细胞出口过程中的功能女儿寄生虫。假定的糖基转移酶活性对于寄生虫生存的重要性将被测试。拟议的研究将使用重组酶来定义这种酶的酶活性糖基转移酶。邻近依赖性生物素化方法与质谱相结合将用于识别相互作用物以及假定的底物。该项目的成功将揭示寄生虫在人类红细胞中进行无性扩张所使用的新颖且必需的糖基化途径血细胞。