Elucidating a G-protein signaling pathway in E. histolytica amoebic colitis

阐明溶组织阿米巴结肠炎中的 G 蛋白信号通路

基本信息

批准号：
8466965
负责人：
Dustin E Bosch
金额：
$ 3.57万
依托单位：
UNIV OF NORTH CAROLINA CHAPEL HILL
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-07-01 至 2014-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8466965
关键词：
Actins Amebiasis Amebic colitis Amoeba genus Binding Biochemical Biological Assay Cell surface Cessation of life Chemotaxis Colitis Complement Cues Cytoskeleton Data Developing Countries Development Drug Targeting Entamoeba histolytica Epithelial Event Extracellular Matrix Family G-Protein Signaling Pathway GTP-Binding Protein Regulators GTP-Binding Proteins Gastroenterologist Genome Guanine Nucleotide Exchange Factors Guanosine Triphosphate Phosphohydrolases Heterotrimeric G Protein Subunit Heterotrimeric GTP-Binding Proteins Homologous Gene Human Infection Intestinal Mucosa Intestines Invaded Knowledge Laboratories Link Mammals Mediating Modeling Molecular Monitor Morbidity - disease rate Mus Nucleotides Nutrient Pathogenesis Pathogenicity Pathway interactions Physicians Play Process Proteins RGS Domain Receptor Aggregation Research Training Role Scientist Signal Pathway Signal Transduction Stimulus Surface System Testing Work World Health X-Ray Crystallography base career cell killing design drug discovery extracellular genome sequencing in vivo indexing knowledge base leukemia mortality novel therapeutic intervention overexpression pathogen receptor research study response rho rho GTP-Binding Proteins rho guanine nucleotide exchange factor p115 skills success

项目摘要

DESCRIPTION (provided by applicant): Ameobic colitis, caused by Entamoeba histolytica, is a major world health burden, resulting in an estimated 100,000 deaths per year. Invasion of the intestinal mucosa by the infectious amoeba trophozoites depends on a dynamic cytoskeleton that is regulated by Rho family GTPases. The Siderovski lab has recently identified the first functional heterotrimeric G proteins (EhG123) and a regulator of G protein signaling (RGS) domain-containing Rho guanine nucleotide exchange factor (GEF) from the E. histolytica genome. My own preliminary data indicates that EhRGS-RhoGEF binds EhG1 in a nucleotide-dependent manner and accelerates the latter protein's GTPase activity. A heterotrimeric G protein signaling pathway, similar to the G112/13 pathway in mammals, likely regulates Rho GTPase activity and thus intestinal invasion by E. histolytica. Furthermore, G protein signaling pathways frequently provide excellent drug targets. In Specific Aim 1, the molecular components of this G protein signaling pathway will be determined by identifying a Rho GTPase substrate for EhRGS-RhoGEF. Biochemical and structural mechanisms for their activation wil be elucidated, using nucleotide exchange assays and X-ray crystallography, respectively. Specific Aim 2 will determine roles for EhG1 and EhRGS-RhoGEF in amoebic intestinal invasion and destruction. The proposed experiments will test whether over- or under-expression of either protein alters the ability of trophozoites to cap surface receptors, invade extracelular matrix, kil intestinal epithelial cels, or invade the intestinal walls of infected mice. These experiments are designed to elucidate a pathogenically important celular signaling cascade in E. histolytica that may be exploited for drug discovery. This work will also provide a potential mechanism for amoebic response to extracellular cues in the intestine, furthering our understanding of the host-pathogen interaction during amoebic colitis. The proposed training and research plans will provide the skills and knowledge base necessary for a successful career as a gastroenterologist physician-scientist.

描述（由申请人提供）：由Entamoeba Histolictica引起的ameobic结肠炎是世界重大的健康负担，每年估计会导致100,000人死亡。传染性变形虫滋养体对肠道粘膜的侵袭取决于由Rho家族GTPase调节的动态细胞骨架。 Siderovski实验室最近已经鉴定出了第一个功能性异三元素G蛋白（EHG123）和G蛋白信号传导（RGS）结构域的调节剂，含有Rho Guanine核苷酸核苷酸交换因子（GEF）。我自己的初步数据表明，Ehrgs-rhogef以核苷酸依赖性方式结合EHG1，并加速了后一种蛋白的GTPase活性。与哺乳动物的G112/13途径相似的异三聚体G蛋白信号通路可能会调节Rho GTPase活性，从而调节E. histolytica的肠侵袭。此外，G蛋白信号通路经常提供出色的药物靶标。在特定的目标1中，该G蛋白信号通路的分子成分将通过鉴定EHRGS-RHOGEF的Rho GTPase底物来确定。分别使用核苷酸交换测定和X射线晶体学分别阐明其激活的生化和结构机制。具体的目标2将确定EHG1和EHRGS-RHOGEF在Amoebic肠道入侵和破坏中的作用。提出的实验将测试任何一种蛋白质的过度表达或表达是否会改变滋养体表面受体的能力，侵袭细胞外基质，kil肠上皮凝胶或侵入感染小鼠的肠壁。这些实验旨在阐明菌E. issolytica中具有病原上重要的CELULUR信号传导级联，该级别可以利用用于药物发现。这项工作还将为肠中细胞外提示反应的潜在机制提供潜在的机制，从而进一步了解我们对阿米巴结肠炎期间宿主 - 病原体相互作用的理解。拟议的培训和研究计划将为成功的职业生涯提供胃肠病学家医师科学家所必需的技能和知识基础。