EncystR: A novel entry point for uncovering the regulation of encystation in Giardia

EncystR：揭示贾第鞭毛虫包囊调控的新切入点

基本信息

批准号：
10335228
负责人：
Alexander Richard Paredez
金额：
$ 19.44万
依托单位：
UNIVERSITY OF WASHINGTON
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-02-01 至 2024-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10335228
关键词：
Amino Acid Transporter Amino Acids Biological Assay Biology Biotin Cell Surface Receptors Cell membrane Cells Client Complement Cyst Data Development Diarrhea Disease Eukaryota Event Future G-Protein-Coupled Receptors Gel Giardia Giardiasis Golgi Apparatus Infection Integral Membrane Protein Intestines Label Ligand Binding Lysosomes Malabsorption Syndromes Membrane Metabolism Microscopy Molecular Conformation Morphology Multivesicular Body Organelles Outcome Study Parasites Pathway interactions Persons Phylogenetic Analysis Physiologic pulse Process Proteins Proton-Translocating ATPases Publishing Regulation Role Signal Transduction Stimulus Testing Therapeutic Time Transmission Electron Microscopy Vesicle attenuation base detection of nutrient experimental study gastrointestinal knock-down metabolomics novel programs protein transport public health relevance receptor recruit sensor small molecule solute spatial relationship theories therapeutic target trafficking transcriptome sequencing

项目摘要

Project Summary Cyst formation is ubiquitous across the diversity of protists, yet its regulation is poorly understood in most species. Major morphological changes occur as the parasite Giardia transitions from proliferative trophozoites to infectious cysts. Importantly, these changes cause the parasites to release from the host intestine, thus this process could be targeted to clear infections. Despite its importance, very little is understood about the signaling events that trigger and sustain Giardia encystation. In an exciting breakthrough, we identified EncystR, a negative regulator of encystation, which represents a novel control point in this developmental program. EncystR is potentially the first encystation receptor identified for any parasite; how it connects with downstream regulation of encystation is unresolved. It has been shown that related proteins can function as sensors, protein trafficking receptors and solute transporters. EncystR localizes to the plasma membrane in vegetative trophozoites, and, upon encystation stimuli, EncystR is internalized. By following EncystR trafficking we identified a novel acidic compartment. This stage induced compartment is marked by ESCRT components typically involved in multivesicular body (MVB) formation. Giardia is thought to lack MVBs and conventional lysosomes, so this discovery was a surprise and represents another exciting therapeutic opportunity. EncystR is the furthest upstream regulator of encystation identified to date; therefore, uncovering its biology will lead to a deeper understanding of the regulation of encystation. Whether EncystR is a GPCR-like receptor that changes conformation upon ligand binding to recruit effector proteins, has a role in solute transport, a role in trafficking proteins to the novel compartment, or some combination remains unknown. Here, we focus on uncovering the mechanistic basis of EncystR’s role in regulating differentiation as well as the purpose of its trafficking to the novel acidic compartment. As the most upstream regulator of encystation identified to date, EncystR is a new entry point for probing this critical, disease-relevant process. The proposed studies will: (1) reveal the EncystR interactome; (2) determine whether or not EncystR transports small molecule metabolites; (3) define the spatial relationship between EncystR and the novel acidic compartment; and (4) uncover the fate of EncystR after reaching the acidic compartment. The outcomes of this study will facilitate the targeting of future mechanistic studies of EncystR and the delineation of the full regulatory cascade needed for encystation.

项目概要囊肿的形成在原生生物的多样性中普遍存在，但在大多数原生生物中，其调控机制却知之甚少。当寄生虫贾第鞭毛虫从增殖滋养体转变时，会发生主要的形态变化。重要的是，这些变化导致寄生虫从宿主肠道中释放出来。尽管该过程很重要，但人们对它知之甚少。我们发现了触发和维持贾第鞭毛虫包囊的信号事件。 EcystR，成囊的负调节因子，代表了这一发育过程中的一个新的控制点 EcystR 可能是第一个被识别的寄生虫的成囊受体；包囊的下游调控尚未解决，相关蛋白质可以发挥作用。传感器、蛋白质运输受体和溶质转运蛋白定位于质膜。植物滋养体，并且在成囊刺激下，EcystR 通过跟随 EcystR 运输而内化。我们发现了一个新的酸性隔室，该阶段诱导的隔室由 ESCRT 成分标记。贾第鞭毛虫通常参与多泡体 (MVB) 形成，但被认为缺乏 MVB 和传统的多泡体 (MVB)。溶酶体，所以这一发现是一个惊喜，代表着另一个令人兴奋的治疗机会。是迄今为止发现的最上游的成囊调节因子，因此，揭示其生物学特性将导致：更深入地了解 EcystR 是否是一种 GPCR 样受体在配体结合时改变构象以招募效应蛋白，在溶质转运中发挥作用，在将蛋白质运输到新的区室，或某些组合仍然未知。在这里，我们关注的是。揭示了 EcystR 调节分化作用的机制基础及其目的作为迄今为止确定的包囊的最上游调节剂， EcystR 是探索这一关键的、与疾病相关的过程的新切入点。拟议的研究将：(1)。揭示EncystR相互作用组；（2）确定EncystR是否转运小分子代谢物； (3) 定义 EcystR 和新型酸性区室之间的空间关系；(4) 揭示命运； EcystR 到达酸性区室后的结果将有助于靶向 EcystR 的未来机制研究以及所需的完整监管级联的描述成囊站。