Regulation of calcium signaling in the human malaria parasite

人类疟疾寄生虫中钙信号传导的调节

• 批准号: 9759759
• 负责人: Silvia N Moreno
• 金额: $ 18.88万
• 依托单位: UNIVERSITY OF GEORGIA
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-10 至 2021-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9759759
• 关键词: Affect; Animal Model; Antimalarials; Area; Back; Binding; Binding Proteins; Biochemical; Biological; Biological Assay; Biological Process; Biology; Biotin; Buffers; CRISPR/Cas technology; Calcium; Calcium Signaling; Calcium ion; Calnexin; Cells; Cessation of life; Clinic; Clinical; Cytoplasm; Cytosol; Data; Defect; Disease; Drug Targeting; Drug resistance; Drug usage; Endoplasmic Reticulum; Erythrocytes; Genes; Genetic; Genome; Goals; Growth; Homeostasis; Human; Infection; Inositol; Ions; Knock-out; Label; Life Cycle Stages; Ligase; Malaria; Malaria Vaccines; Molecular; Organelles; Organism; Parasites; Pathway interactions; Plasmodium; Plasmodium falciparum; Population; Proteins; Regulation; Research; Resistance; Resistance development; Role; Ryanodine Receptor Calcium Release Channel; Sexual Development; Signal Pathway; Signal Transduction; System; Transmembrane Domain; asexual; base; conditional mutant; drug development; experimental study; falls; gene therapy; human disease; knock-down; loss of function; mortality; mutant; new therapeutic target; novel; obligate intracellular parasite; parasite invasion; receptor; resistant strain; response; uptake

Project Summary The deadliest form of human malaria is caused by the eukaryotic parasite Plasmodium falciparum, which is responsible for nearly 450,000 deaths every year. Nearly half of the world’s population lives in areas where malaria is endemic, resulting in almost ~250 million infections each year. As yet, there are no effective vaccines against malaria and antimalarial drugs are the mainstay of treatment. Unfortunately, the parasite has gained resistance to all antimalarial drugs used in the clinic and these drug-resistant strains are spreading throughout the world. Thus, it is crucial that we constantly identify potential novel drug targets to stay ahead of this deadly disease. Understanding the signaling pathways that drive the biology of the parasite will provide new antimalarial drug targets that are unique to the parasite and absent in the host. Calcium ion (Ca2+) signaling has emerged as one of the major drivers of the life cycle of P. falciparum. The goal of this proposal is to study Ca2+ signaling and the pathways that regulate ion fluctuations in malaria parasites. In P. falciparum, similar to other eukaryotic organisms, the cytoplasmic levels of Ca2+ is very low and its concentration rises in the cytoplasm in response to specific signals. This increased cytosolic Ca2+ results in a signaling cascade that that is essential for the life cycle of the parasite. Once the signal subsides, the levels of cytosolic Ca2+ falls back via uptake into intracellular Ca2+ stores, such as the endoplasmic reticulum. The P. falciparum genome lacks several canonical genes that are known to be essential for Ca2+ signaling in other well- studied eukaryotic organisms. Therefore, we will target the only soluble protein with Ca2+ binding domains that localizes to the major intracellular Ca2+ store, the endoplasmic reticulum. We hypothesize that this protein regulates the release and uptake of Ca2+ from this organelle. Our preliminary data show that this gene is essential for the asexual life cycle of the parasite and is required for the invasion of the parasite into its host red blood cell. We will utilize genetic, cellular, and biochemical approaches to define the role of this gene in regulating Ca2+ signaling and the invasion of P. falciparum into the host cell. These include the use of genetically encoded Ca2+ indicators to reveal the fluctuations of Ca2+ during the intraerythrocytic life cycle of P. falciparum as well as the effect of genetic interventions on the homeostasis of Ca2+. A second independent proximity-based labeling approach will be undertaken to isolate and discover novel partners of the targeted gene to define the network of genes required to regulate the flow of Ca2+ within the P. falciparum infected human red blood cells. Achieving the aims of this study will reveal the essential parasite-specific pathways that regulate Ca2+ signaling, which can be targeted for antimalarial drug development.

项目概要 人类疟疾最致命的形式是由真核寄生虫恶性疟原虫引起的， 每年造成近 45 万人死亡。世界上近一半的人口居住在 疟疾流行地区，每年导致近 2.5 亿人感染。迄今为止，还有 没有有效的疟疾疫苗，抗疟药物是主要治疗方法。 不幸的是，这种寄生虫已经对临床上使用的所有抗疟药物产生了耐药性，而这些药物 耐药菌株正在全世界蔓延。因此，我们不断地识别是至关重要的 潜在的新药物靶标可以领先于这种致命疾病。了解信号通路 驱动寄生虫生物学的药物将提供独特的新抗疟药物靶点 寄生在宿主体内且不存在。钙离子 (Ca2+) 信号传导已成为主要驱动因素之一 恶性疟原虫的生命周期。该提案的目标是研究 Ca2+ 信号传导和途径 调节疟疾寄生虫中的离子波动。在恶性疟原虫中，与其他真核生物相似 在生物体中，细胞质中Ca2+的水平非常低，并且其浓度在细胞质中升高 对特定信号的响应。胞质 Ca2+ 的增加导致信号级联反应，即 对于寄生虫的生命周期至关重要。一旦信号消退，胞质 Ca2+ 水平就会下降 通过摄取细胞内 Ca2+ 储备（例如内质网）返回。恶性疟原虫 基因组缺乏几个已知对其他良好的 Ca2+ 信号传导至关重要的经典基因 研究真核生物。因此，我们将靶向唯一与 Ca2+ 结合的可溶性蛋白质 定位于主要细胞内 Ca2+ 储存（内质网）的结构域。我们假设 该蛋白质调节该细胞器中 Ca2+ 的释放和吸收。我们的初步数据显示 该基因对于寄生虫的无性生命周期至关重要，并且是入侵寄生虫所必需的 寄生虫进入其宿主红细胞。我们将利用遗传、细胞和生化方法来 定义该基因在调节 Ca2+ 信号传导和恶性疟原虫入侵宿主中的作用 细胞。其中包括使用基因编码的 Ca2+ 指示剂来揭示 Ca2+ 的波动 恶性疟原虫的红细胞内生命周期以及遗传干预对恶性疟原虫红细胞内生命周期的影响 Ca2+ 的稳态。将采用第二种独立的基于邻近性的标签方法 分离并发现目标基因的新伙伴，以定义所需的基因网络 调节恶性疟原虫感染的人红细胞内 Ca2+ 的流动。实现以下目标 这项研究将揭示调节 Ca2+ 信号传导的重要寄生虫特异性途径，这些途径可以 抗疟药物开发的目标。