权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Regulation of mitochondrial morphodynamics in Toxoplasma gondii

弓形虫线粒体形态动力学的调控

基本信息

批准号：
9896491
负责人：
Gustavo A Arrizabalaga
金额：
$ 39.28万
依托单位：
INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-03-03 至 2025-02-28
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/9896491
关键词：
Address Affect Amino Acids Apical Apicomplexa Automobile Driving Auxins Biochemistry Biological Assay Biology Biotinylation Calcium Cells Cessation of life Co-Immunoprecipitations Complex Coupling Cytokinesis Development Disease Drug Targeting Economic Burden Environment Homeostasis Image Immunocompromised Host In Vitro Individual Knock-out Lasso Lead Life Life Cycle Stages Light Lipids Lytic Phase Maps Mechanics Mediating Membrane Microscopy Mitochondria Molecular Molecular Genetics Monitor Morphology Mutation Analysis Organelles Parasites Pharmaceutical Preparations Phenotype Phosphorylation Site Physiology Plasmodium falciparum Play Population Positioning Attribute Post-Translational Protein Processing Process Proteins Proteomics Regulation Research Resistance Role Shapes Site Societies Stretching Structure System Toxoplasma Toxoplasma gondii Toxoplasmosis Transmembrane Domain Tubular formation Yeasts base combat daughter cell experimental study extracellular health economics human pathogen in vivo mutant novel novel therapeutics pathogen protein complex segregation tissue culture yeast two hybrid system

项目摘要

A unique feature of parasites of the phylum Apicomplexa, such as Toxoplasma gondii, is the presence of a single tubular mitochondrion, which is essential for parasite survival and a validated drug target. Most studies of the apicomplexan mitochondrion have focused on its biochemistry and physiology. By contrast little is known about the machinery that controls mitochondrial division and that regulate its structure, information that would be critical for a thorough exploration of the mitochondrion as a drug target. Toxoplasma's singular mitochondrion is very dynamic and undergoes morphological changes throughout the parasite's life cycle including during the transition from the intracellular to the extracellular environment. While inside a host cell the mitochondrion is maintained in a lasso shape that stretches around the parasite periphery where it has regions of coupling with the parasite pellicle, suggesting the presence of membrane contact sites. Promptly after exit from the host cell, these contact sites disappear, and the mitochondrion collapses indicating that dynamic membrane contact sites regulate the positioning of the mitochondrion. Neither the functional significance nor the proteins needed for the contact between Toxoplasma's mitochondrion and pellicle are known. We have discovered a novel protein, Fip1, that associates with the mitochondrion and that when knocked out the normal morphology of the mitochondrion is severely affected. In intracellular fip1 knockout parasites the mitochondrion is not in a lasso shape as seen in wildtype parasites, but instead it is collapsed. Additionally, proper mitochondrial segregation is disrupted in the knockout parasites, resulting in parasites with no mitochondrion and mitochondrial material outside of the parasites. These gross morphological changes are associated with a significant reduction of parasite propagation and can be rescued by reintroduction of a wildtype copy of Fip1. Accordingly, we hypothesize that Fip1 mediates contact between the mitochondrion and the parasite pellicle in a regulatable fashion, and that the Fip1 dependent mitochondrial morphology and dynamics are critical for parasite propagation. Through a combination of molecular genetics, microscopy and proteomics we will address the functional relevance and the mechanics of the mitochondrial morphology. In aim one we will conduct a thorough in vivo and in vitro phenotypic characterization of Fip1 mutant strains to determine the role of Fip1 and mitochondrial shape in parasite viability. Aim two focuses on identifying and characterizing components of the Fip1 complex that mediates the association of the mitochondrion with the periphery of the parasites. Finally, in aim three we will determine the regulatory mechanisms that drive the mitochondrial morphological changes as the parasite exits its host cell. In conjunction, these experiments will shed light onto the molecular mechanisms driving and regulating the morphodynamics of the Toxoplasma mitochondrion. As the mitochondrion of this important human pathogen is essential for its survival and a validated drug target, our studies will uncover novel targets for the development on new therapeutics.

顶复合体门的寄生虫，如刚地弓形虫，有一个独特的特征