Inhibitors of Type III Secretion and Translocation in yersinia

耶尔森氏菌 III 型分泌和易位抑制剂

• 批准号: 7681382
• 负责人: Joan C Mecsas
• 金额: $ 41.15万
• 依托单位: TUFTS UNIVERSITY BOSTON
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-15 至 2011-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7681382
• 关键词: Alleles; Bacteria; Bacterial Proteins; Binding; Biochemical; Biochemical Genetics; Biological Assay; Burkholderia; Cell membrane; Cell physiology; Cells; Cellular biology; Cytoplasm; Cytosol; Data; Defect; Development; Disease; Distal; Dominant-Negative Mutation; Exposure to; Goals; Host Defense; In Vitro; Investigation; Mammalian Cell; Membrane; Microscopic; Molecular; Molecular Machines; Mutation; Needles; Pathogenesis; Play; Positioning Attribute; Process; Proteins; Pseudomonas; Resistance; Role; Salmonella; Shigella; Signal Transduction; Surface; System; Thinking; Travel; Tube; Type III Secretion System Pathway; Virulence; Work; Yersinia; Yersinia pestis V antigen; base; enteropathogenic Escherichia coli; inhibitor/antagonist; mutant; pathogen; polymerization; prevent; protein structure; small molecule

Many gram negative bacterial pathogens, including Yersinia, Salmonella, Pseudomonas, Shigella, enteropathogenic E. coli, Chylamydia, and Burkholderia, use type III secretion systems (TTSS) to translocate effector proteins from the bacterial cytosol into mammalian cells. Translocated effector proteins, called Yops in Yersinia, subvert normal host processes to promote the survival of the pathogen, and thus TTSS play an essential role in the infectious process and virulence of these bacteria. TTSS are comprised of a base, which spans the inner and outer membranes of the bacteria, a needle, which extends from the base to the host cell, and a translocon, which is inserted into host cell membranes and through which Yops are thought to travel to reach host cell cytoplasm. In Yersinia, the needle is primarily composed of one 7kD protein, YscF, which polymerizes to form a long tube. The needle is thought to be a conduit for the passage of Yops from the bacteria to the translocon and is thought to conduct signals from the host cell membrane to the TTSS base when the pathogen comes in contact with a host cell. These signals trigger Yop translocation. A tip protein, LcrV, is found at the distal end of the needle. One function of LcrV is to position, assemble, and/or insert the translocon, into plasma membranes, which is essential for Yop delivery into cells. Two proteins, YopB and YopD comprise the translocon. The overall goals of this proposal are to understand the molecular interactions between TTSS components that are required for translocating Yops upon contact with mammalian cells. We have identified 3 dominant negative YscF alleles and 8 small molecules that inhibit Yop translocation. These unique mutants and compounds will be studied intensively as probes to understand the required molecular interactions for Yop translocation into host cells. Our working hypothesis is that our inhibitors interfere with critical interactions between YscF, LcrV, YopB and/or YopD. Understanding the mechanism of translocation and needle assembly will support the development of new strategies that interfere with these processes and thus neutralize the bacteria's pathogenecity.

许多革兰氏阴性细菌病原体，包括耶尔森氏菌、沙门氏菌、假单胞菌、志贺氏菌， 肠致病性E.大肠杆菌、乳糜阿米巴和伯克霍尔德氏菌使用III型分泌系统（TTSS）易位 效应蛋白从细菌胞质溶胶进入哺乳动物细胞。转运效应蛋白，称为Yops， 耶尔森氏菌，破坏正常的宿主过程，促进病原体的生存，从而TTSS发挥作用， 在这些细菌的感染过程和毒力中起重要作用。TTSS由底座组成，底座 跨越细菌的内膜和外膜，一根针，从基部延伸到宿主细胞， 和一个易位子，它插入宿主细胞膜，Yops被认为是通过它旅行到 到达宿主细胞质。在耶尔森氏菌中，针主要由一种7 kD蛋白YscF组成， 聚合形成长管。针被认为是一个管道的通道Yops从 细菌的转座子，并被认为是从宿主细胞膜的TTSS基地进行信号 当病原体与宿主细胞接触时。这些信号触发Yop易位。一种顶端蛋白， 在针的远端发现LcrV。LcrV的一个功能是定位、组装和/或插入 转运子进入质膜，这对于Yop递送到细胞中是必需的。两种蛋白质，YopB和 YopD包含易位子。本提案的总体目标是了解分子相互作用 在与哺乳动物细胞接触时易位Yops所需的TTSS组分之间。我们 已经鉴定了3个显性负YscF等位基因和8个抑制Yop易位的小分子。这些 独特的突变体和化合物将作为探针进行深入研究，以了解所需的分子 Yop易位进入宿主细胞的相互作用。我们的工作假设是我们的抑制剂干扰了 YscF、LcrV、YopB和/或YopD之间的关键相互作用。了解易位的机制 和针组件将支持干扰这些过程的新策略的开发， 从而中和细菌的致病性。