Mechanisms of ARF6 function in Shigella entry

ARF6在志贺氏菌进入中的功能机制

• 批准号: 9050509
• 负责人: Anna Cristina Garza-Mayers
• 金额: $ 4.86万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-01-01 至 2018-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9050509
• 关键词: 5 year old; ADP-ribosylation factor 6; Actins; Bacteria; Bacterial Infections; Biochemical; Biochemical Genetics; Biological; Biological Process; Cell surface; Cells; Cessation of life; Child; Colon; Communicable Diseases; Cytoplasm; Cytoskeleton; Data; Developing Countries; Development; Diarrhea; Disease; Endosomes; Eukaryotic Cell; Fluorescence Microscopy; Fostering; Guanine Nucleotide Exchange Factors; Guanosine Triphosphate Phosphohydrolases; Human; Infection; Invaded; Knowledge; Mediating; Membrane Protein Traffic; Metabolism; Molecular; Monomeric GTP-Binding Proteins; Mucous Membrane; Oral; Organism; Pathogenesis; Phosphatidylinositols; Phosphoric Monoester Hydrolases; Physicians; Process; Proteins; Publishing; Recruitment Activity; Rickettsia; Role; Salmonella; Scientist; Shigella; Shigella flexneri; Signal Pathway; Signal Transduction; Site; Staging; Techniques; Testing; Training; Tuberculosis; Type III Secretion System Pathway; Vacuole; Virulence; Water Supply; Work; base; contaminated water; genetic approach; improved; insight; lipid metabolism; pathogen; public health relevance; transmission process; uptake

 DESCRIPTION (provided by applicant): Shigella species are a common cause of bacterial diarrhea worldwide, particularly in developing countries. Usually spread by contaminated water supply, these Gram-negative pathogens are capable of invading and replicating within mucosal cells of the human colon. Entry into the host cell is critical for Shigella virulence but incompletly understood. It is apparent that the bacteria manipulates host cytoskeleton and signaling pathways by means of a repertoire of proteins secreted by a type III secretion system (T3SS). As part of an effort to elucidate the bacterial entry process, my preliminary work shows that Shigella flexneri entry is decreased in the absence of host small GTPase ADP-ribosylation factor 6 (ARF6), indicating that ARF6 is important for Shigella pathogenesis. ARF6 is known to act at the host cell surface and at endosomes to regulate membrane trafficking, lipid metabolism, and actin remodeling. My preliminary studies also indicate that the T3SS effector IpgD is critical for efficient entry and ARF6 activation. Using fluorescence microscopy-based and biochemical techniques, I propose to determine how ARF6 contributes to efficient S. flexneri entry and to characterize the mechanism by which IpgD enhances activation of ARF6 during S. flexneri entry. My specific aims are to: 1. Determine the mechanism(s) by which ARF6 contributes to efficient S. flexneri entry. 2. Determine the mechanism(s) of ARF6 activation by S. flexneri. This proposal combines cell biological, biochemical, and genetic approaches to test my hypothesis and further our understanding of the mechanism(s) of Shigella entry. In addition to adding insight to current knowledge of basic cell biological processes and signaling, this work will contribute to our understanding of intracellular bacterial infection and may improve treatment of such infections, which include not only diarrheal disease caused by S. flexneri and Salmonella species but other infectious diseases such as rickettsia and tuberculosis.

 描述（由适用提供）：志贺氏菌种是全球细菌腹泻的常见原因，尤其是在发展中国家。这些革兰氏阴性病原体通常通过受污染的供水传播，能够在人类结肠的粘膜细胞内入侵和复制。进入宿主细胞对于志贺氏菌病毒至关重要，但不完全理解。显然，细菌通过由III型分泌系统（T3SS）分泌的蛋白质曲目操纵宿主的细胞骨架和信号通路。作为阐明细菌进入过程的努力的一部分，我的初步工作表明，在没有宿主的小GTPase ADP-ribosylation因子6（ARF6）的情况下，Shigella Flexneri进入降低了，这表明ARF6对志贺氏菌病原体很重要。已知ARF6在宿主细胞表面和内体作用，以调节膜运输，脂质代谢和肌动蛋白重塑。我的初步研究还表明，T3SS效应IPGD对于有效进入和ARF6激活至关重要。使用基于荧光显微镜和生化技术，我建议确定ARF6如何有助于有效的S. flexneri进入，并表征IPGD在S. flexneri进入过程中增强ARF6激活的机制。我的具体目的是：1。确定ARF6有助于有效的S. flexneri进入的机制。 2。确定S. flexneri激活ARF6激活的机制。该建议结合了细胞生物学，生化和遗传方法，以检验我的假设并进一步了解我们对志贺氏菌进入机制的理解。除了对基本细胞生物过程和信号传导的当前知识增加深入了解外，这项工作还将有助于我们对细胞内细菌感染的理解，并可能改善治疗 在此类感染中，不仅包括由弯曲链球菌和沙门氏菌引起的腹泻疾病，还包括其他感染性疾病，例如立克西亚和结核病。