Functional Analysis of the T. gondii AMA1 Cytosolic Tail

刚地弓形虫 AMA1 胞质尾的功能分析

基本信息

批准号：
8630571
负责人：
GARY E WARD
金额：
$ 38.13万
依托单位：
UNIVERSITY OF VERMONT & ST AGRIC COLLEGE
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-11-15 至 2018-10-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8630571
关键词：
Acquired Immunodeficiency Syndrome Acute Address Affect Aldehyde-Lyases American Animal Model Antigens Apical Attention Binding Binding Proteins Biological Assay Biological Process C-terminal Cause of Death Cell membrane Cell surface Cells Cleaved cell Cryptosporidiosis Cytosol Disease Event Experimental Models Extracellular Domain Goals Human Hybrids Immunocompromised Host Individual Infection Integral Membrane Protein Invaded Life Life Cycle Stages Ligands Link Malaria Malaria Vaccines Mediating Mutation Names Organelles Parasites Pathogenesis Phosphorylation Play Population Pregnancy Protein Binding Proteins Research Role Signal Pathway Signal Transduction Staging Surface Tail Testing Toxoplasma gondii Toxoplasmosis Transmembrane Domain Work Yeasts apical membrane cost design drug development foodborne illness genetic analysis in vivo knowledge of results novel novel strategies pathogen prevent protein function public health relevance receptor research study vaccine candidate vaccine development

项目摘要

Toxoplasma gondii is a widespread protozoan parasite that causes debilitating and sometimes life- threatening disease during pregnancy and in immunocompromised individuals, including those with AIDS. Toxoplasmosis is the second most common cause of death by foodborne illness in the USA and costs the economy billions of dollars annually. T. gondii is also a valuable experimental model for related apicomplexan parasites, including those that cause malaria and cryptosporidiosis. Host cell invasion is essential to the parasite's life cycle, and apical membrane antigen1 (AMA1) is a highly conserved transmembrane protein on the parasite surface that plays an important role in invasion. Much is known about how the extracellular domain of AMA1 interacts with its ligand on the host cell surface (RON2) during invasion, but surprisingly little is known about the function of its short, C-terminal tail, which is located in the parasite cytosol. The central hypothesis of this project is that the cytosolic tail of T. gondii AMA1 (TgAMA1) functions in invasion-related signaling pathways, through interaction with other parasite proteins. The Aims of the project are to: (a) Determine the phenotypic consequences of specific mutations in the TgAMA1 cytosolic tail, establishing at what step(s) in invasion the cytosolic tail functions and the specific residues involved; (b) Identify and determine the biological function of proteins that interact with the TgAMA1 cytosolic tail, establishing whether tail mutations that disrupt invasion also affect the binding of specific proteins; and (c) Determine whether the binding of TgAMA1 to TgRON2 triggers intracellular signaling mediated by the TgAMA1 cytosolic tail, resulting in invasion-related changes to the parasite phosphoproteome. These studies address a significant gap in our understanding of the role that AMA1 plays in the invasion of host cells by apicomplexan parasites. A more complete understanding of AMA1 function will generate new approaches to preventing or controlling the devastating diseases caused by this important group of human pathogens.

弓形虫Gondii是一种广泛的原生动物寄生虫，会使人衰弱，有时甚至是生命 - 威胁怀孕期间的疾病和免疫功能低下的个体，包括患有艾滋病的人。弓形虫病是美国食源性疾病的第二大最常见的死亡原因，成本经济每年数十亿美元。 T. gondii也是相关apicomplexan的宝贵实验模型寄生虫，包括引起疟疾和隐孢子虫病的寄生虫。宿主细胞侵袭对于寄生虫的生命周期和顶膜抗原1（AMA1）是高度保守的跨膜蛋白在入侵中起重要作用的寄生虫表面。关于细胞外如何了解 AMA1的域与其在入侵期间与宿主细胞表面（RON2）上的配体相互作用，但令人惊讶的是很少已经知道其短的C末端尾巴的功能，该尾巴位于寄生虫细胞质中。中央该项目的假设是T. gondii AMA1（TGAMA1）的胞质尾巴在与入侵有关信号通路，通过与其他寄生虫蛋白相互作用。该项目的目的是：（a）确定tgama1胞质尾巴中特定突变的表型后果，建立在入侵中，胞质尾部功能和涉及的特定残基在什么步骤中；（b）识别并确定与Tgama1胞质尾巴相互作用的蛋白质的生物学功能，确定破坏侵袭的尾突变是否也会影响特定蛋白的结合；和（c）确定tgama1与tgron2的结合是否触发由介导的细胞内信号传导 TGAMA1胞质尾巴，导致与寄生虫磷酸蛋白酶的侵袭相关的变化。这些研究解决了我们对AMA1在入侵中所起的作用的明显差距 Apicomplexan寄生虫的宿主细胞。对AMA1功能的更完整的了解将产生新的预防或控制由这一重要人类引起的毁灭性疾病的方法病原体。