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: 10531601
• 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/10531601
• 关键词: 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; Invaded; 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; biodefense; cell motility; crosslink; experimental study; extracellular; fitness; genome wide screen; migration; model organism; novel; novel therapeutics; opportunistic pathogen; parasite invasion; parasitism; 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. 项目概要/摘要 顶复门寄生虫包括人类和牲畜许多广泛感染的病原体， 例如疟疾和弓形体病。这些疾病是由于宿主组织遭到破坏而引起的。 寄生虫会复制。由于apicomplexans仅在宿主细胞内复制，因此入侵过程对于宿主细胞的复制至关重要。 它们的生存和发病机制。入侵是由专门分泌的蛋白质释放介导的 寄生虫顶端的细胞器、微线体和棒状体。微线体蛋白包括 支持寄生虫运动的粘附素，因此一旦寄生虫从复制中出现就会分泌 并开始迁移到新的宿主细胞进行感染。相比之下，棒状体仅在以下情况下分泌其内容物： 一旦寄生虫入侵，宿主细胞就会识别。有证据表明，棒状体的释放 含量取决于微线体蛋白的先前分泌；然而，将这些联系起来的分子事件 两个进程未知。基于顶复门弓形虫模型的全基因组筛选， 我们的实验室最近发现了一种入侵人类细胞所必需的保守微线体蛋白，我们将其 命名为 CLAMP。我们的初步研究表明，CLAMP对于棒状体的分泌和稳定是必需的。 与两种微线体蛋白相关：SPATR（之前与入侵有关）和 我们将未表征的蛋白质称为 CLIP。我们假设这些相互作用代表了一种新的入侵 菱形蛋白分泌所必需的复合物。我们的第一个目标是比较 CLAMP 的功能， SPATR 和 CLIP；研究它们如何寡聚；并阐明复杂之间的关系 形成和菱形分泌。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 与 CLAMP 入侵复合体相互作用。最后，我们的第三个目标是公正地看待宿主细胞 刺激棒状体蛋白分泌的因素，这些因素可能与 CLAMP 复合物交叉来调节 apicomplexan 入侵的关键步骤。基于所涉及的寄生虫蛋白的保守性，我们预计 所揭示的原理将推广到整个门，并广泛地影响我们对这些原理的理解 传染源。