Control of parasite invasion by a microneme protein complex conserved in Apicomplexans

顶复门中保守的微线体蛋白复合物控制寄生虫入侵

• 批准号: 9886387
• 负责人: Sebastian Lourido
• 金额: $ 48.75万
• 依托单位: WHITEHEAD INSTITUTE FOR BIOMEDICAL RES
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-12-01 至 2024-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9886387
• 关键词: Animal Model; Animals; Apical; Apicomplexa; Bacterial Adhesins; Binding; Biochemical; Biological Assay; Biotin; CRISPR screen; Carbohydrates; Categories; Cell Membrane Permeability; Cell Surface Proteins; Cell surface; Cells; Chemicals; Clustered Regularly Interspaced Short Palindromic Repeats; Complement; Complex; Conserved Sequence; Cryptosporidiosis; Cryptosporidium; Dependence; Development; Disease; Distant; Etiology; Event; Face; Fibroblasts; Fluorescence-Activated Cell Sorting; Genes; Genetic; Human; Impairment; Infection; Infectious Agent; Integration Host Factors; Ligase; Link; Lipids; Livestock; Lytic Phase; Malaria; Mediating; Modeling; Molecular; Names; National Institute of Allergy and Infectious Disease; Organelles; Parasite Control; Parasites; Pathogenesis; Phenotype; Plasmodium; Plasmodium falciparum; Play; Process; Protein Secretion; Protein translocation; Proteins; Regulation; Scheme; Signal Transduction; Structure; Surface; Symptoms; System; Tissues; Toxoplasma gondii; Toxoplasmosis; Ursidae Family; base; biodefense; cell motility; crosslink; experimental study; extracellular; fitness; genome wide screen; novel; novel therapeutics; parasite invasion; parasitism; pathogen; preservation; prophylactic; protein complex; rhoptry; trafficking

7. PROJECT SUMMARY/ABSTRACT Apicomplexan parasites include the etiologic agents of many widespread infections of humans and livestock, such as malaria and toxoplasmosis. These diseases are caused by destruction of the host tissues in which the parasites replicate. Because apicomplexans only replicate inside host cells, the process of invasion is critical to their survival and pathogenesis. Invasion is mediated by the release of proteins from specialized secretory organelles at the apical end of the parasite, the micronemes and rhoptries. Microneme proteins include adhesins that support parasite motility and are therefore secreted as soon as parasites emerge from replication and start migrating towards new host cells to infect. Rhoptries, by contrast, secrete their contents only upon host cell recognition once parasites have committed to invasion. Evidence suggests that the release of rhoptry contents depends on the prior secretion of microneme proteins; however, the molecular events that link these two processes are unknown. Based on a genome-wide screen in the model apicomplexan Toxoplasma gondii, our lab recently identified a conserved microneme protein necessary for invasion of human cells, which we named CLAMP. Our preliminary studies show that CLAMP is necessary for rhoptry secretion and stably associates with two microneme proteins: SPATR, which was previously implicated in invasion, and an uncharacterized protein we call CLIP. We hypothesize that these interactions represent a novel invasion complex necessary for rhoptry protein secretion. Our first aim is to compare the functions of CLAMP, SPATR, and CLIP; investigate how they oligomerize; and elucidate the relationship between complex formation and rhoptry secretion. In our second aim, we will identify and characterize host and parasite proteins that interact with the CLAMP invasion complex. Finally, our third aim will take an unbiased look at the host cell factors that stimulate rhoptry protein secretion, which may intersect with the CLAMP complex to regulate this key step in apicomplexan invasion. Based on the conservation of the parasite proteins involved, we expect that the principles uncovered will be generalizable to the phylum and broadly inform our understanding of these infectious agents.

7。项目摘要/摘要 Apicomplexan寄生虫包括许多广泛感染人类和牲畜的病因学剂， 例如疟疾和弓形虫病。这些疾病是由宿主组织破坏引起的 寄生虫复制。由于仅在宿主细胞内复制Apicomplexans，因此入侵过程至关重要 它们的生存和发病机理。侵袭是由专门分泌的蛋白质释放而介导的 寄生虫的顶端，微分子和rhoptries的细胞器。微原质蛋白包括 支持寄生虫运动的粘附素，因此在复制中出现后立即分泌 并开始向新的宿主细胞迁移以感染。相比之下，Rhoptries仅在 一旦寄生虫致力于入侵，宿主细胞识别。有证据表明，释放Rhoptry 含量取决于先前的微蛋白蛋白分泌。但是，将这些连接的分子事件 两个过程未知。基于模型apicomplexan弓形虫弓形虫中的全基因组屏幕， 我们的实验室最近确定了一种保守的微素蛋白，用于侵袭人类细胞，我们 命名为钳。我们的初步研究表明，夹具是Rhoptry分泌所必需的，并且稳定 与两种微蛋白蛋白合作：SPATR，以前与入侵有关，一个 未表征的蛋白质我们称为夹子。我们假设这些相互作用代表了一种新颖的入侵 Rhoptry蛋白分泌所必需的复杂。我们的第一个目的是比较夹具的功能， spatr和剪辑；研究它们的低聚方式；并阐明复杂之间的关系 形成和分类分泌。在我们的第二个目标中，我们将识别和表征宿主和寄生虫蛋白 那与夹具入侵配合物相互作用。最后，我们的第三个目标将无偏见 刺激Rhoptry蛋白分泌的因素，该因素可能与夹具复合物相交以调节这一点 Apicomplexan入侵的关键步骤。根据所涉及的寄生虫蛋白的保护，我们希望 发现的原则将推广到门，并广泛地告知我们对这些的理解 感染者。