Yessinia autotransporters (Yaps): Structure, function, and host response

Yessinia 自转运蛋白 (Yaps)：结构、功能和宿主响应

• 批准号: 8375890
• 负责人: VIRGINIA L MILLER
• 金额: $ 21.34万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-03-01 至 2014-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8375890
• 关键词: Affect; Amino Acids; Biological; Biological Process; Biology; Bubonic Plague; Cell surface; Complement; Computer Simulation; Data; Deletion Mutation; Fleas; Foundations; Future; Immune response; Infection; Location; Membrane; Modeling; Molecular; Molecular Genetics; Mutation; Organism; Pathogenesis; Peptide Signal Sequences; Phenotype; Play; Positioning Attribute; Proteins; Role; Screening procedure; Structure; Surface; Testing; Vent; Virulence; Virulent; Work; Yersinia pestis; base; biodefense; inhibitor/antagonist; mutant; novel; pathogen; protein complex; response; small molecule; therapeutic vaccine

Autotransporter proteins (ATs) are exceptionally elegant yet complex proteins ideally positioned on the bacterial cell surface (or released) for interactions with the host. ATs consist of three basic domains: a Nterminal signal sequence, a "passenger domain" (PD) of variable size and finally a (3-domain of 250-300 amino acids at the C-terminus that facilitates translocation of the PD across the outer membrane. Although more than 1000 have been identified by in silico analyses a relatively few have been studied in detail as to their molecular and biological function. The Yaps (predicted ATs) of Y. pestis represent an excellent opportunity to do this as (a) they do not appear to be closely related to the already well studied ATs and thus are likely to encode novel functions, and (b) Y. pestis is amenable to molecular, genetic and biological studies. We have, preliminary data indicating that all ten of the yaps are expressed during infection. We also demonstrated that most of the Yaps are localized and exposed on the bacterial surface, while the others appear to be released into the culture supernatant. In addition, we have constructed deletion mutations in all of the ten yaps in a fully virulent Y. pestis strain and have begun testing the effect of these mutations on virulence. While these tests are ongoing, four of these mutants clearly have phenotypes in a bubonic plague model of infection. These results are consistent with our hypothesis that the yaps play a role in pathogenesis. The studies proposed here to examine the host response to Y. pestis and the role of Yaps in hat response (Aims 1 & 2) are based on the observation that many yap mutations appear to affect early vents and/or dissemination of Y. pestis. These studies should inform us not only about key host responses during Y. pestis infection, but they should also give us important clues as to host targets of the Yaps. This ll complement the structural work described in Aim 3 aimed at defining important functional domains of the Yaps and also at providing a foundation for future screening for broad spectrum small molecule inhibitors of ATs.

自转运蛋白 (AT) 是极其优雅且复杂的蛋白质，理想地定位在 细菌细胞表面（或释放）与宿主相互作用。 AT 由三个基本域组成： Nterminal 信号序列，可变大小的“乘客域”（PD），最后是 250-300 的（3 域） C 末端的氨基酸有助于 PD 跨外膜易位。虽然 超过 1000 种已通过计算机分析被识别，相对少数已被详细研究 它们的分子和生物学功能。鼠疫耶尔森菌的 Yaps（预测 AT）代表了一种极好的 这样做的机会，因为（a）它们似乎与已经充分研究的 AT 没有密切相关，因此 可能编码新功能，并且 (b) 鼠疫耶尔森氏菌易于分子、遗传和生物学研究 研究。我们的初步数据表明，所有 10 种雅普声都是在感染期间表达的。我们也 证明大多数 Yaps 都集中在细菌表面并暴露在细菌表面，而其他的 似乎被释放到培养物上清液中。此外，我们还构建了所有的缺失突变 完全致命的鼠疫耶尔森菌株中的十个雅普，并已开始测试这些突变对 毒力。虽然这些测试正在进行中，但其中四种突变体显然具有黑死病的表型 感染模型。这些结果与我们的假设一致，即雅普在 发病。这里提出的研究旨在检查宿主对鼠疫耶尔森氏菌的反应以及Yaps在 帽子反应（目标 1 和 2）基于以下观察：许多 yap 突变似乎影响早期 鼠疫杆菌的通风口和/或传播。这些研究不仅应该告诉我们关键的宿主反应 但它们也应该为我们提供有关雅普犬宿主目标的重要线索。这 将补充目标 3 中描述的结构工作，旨在定义重要的功能域 Yaps 还为未来筛选广谱小分子抑制剂奠定了基础 AT。