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

自动转运蛋白(ATS)是一种非常优雅而复杂的蛋白质，理想地定位在 细菌细胞表面(或释放)与宿主相互作用。自动测试系统由三个基本域组成：一个N终端 信号序列，可变大小的“乘客域”(PD)，最后是(250-300的3个域 C末端的氨基酸，促进钯在外膜上的转移。虽然 有1000多个已经通过电子分析确定了，相对较少的人被详细研究过 它们的分子和生物学功能。鼠疫耶尔森氏菌的YAPS(预测的AT)代表了一种优秀的 这样做的机会是：(A)它们似乎与已经研究得很好的安非他明类兴奋剂没有密切联系，因此 可能编码新的功能，以及(B)鼠疫杆菌对分子、遗传和生物学具有敏感性 学习。我们有初步数据表明，所有10个YAP在感染期间都有表达。我们也 证明大多数羊膜是定位并暴露在细菌表面，而其他的 似乎被释放到培养上清液中。此外，我们还构建了所有基因的缺失突变 在一个完全毒力的鼠疫菌株中的十个Yap中的一个，并已经开始测试这些突变对 致命性。虽然这些测试仍在进行中，但其中四个突变体显然具有腺鼠疫的表型。 感染模式。这些结果与我们的假设一致，即YAP在 发病机制。本研究旨在研究宿主对鼠疫耶尔森氏菌的反应以及YAP在鼠疫中的作用。 HAT反应(目标1和2)是基于观察到许多YAP突变似乎影响早期 鼠疫杆菌的通风口和/或传播。这些研究不仅应该让我们了解关键的宿主反应 在鼠疫耶尔森氏菌感染期间，但它们也应该为我们提供关于YAP宿主目标的重要线索。这 我将补充目标3中描述的结构工作，目的是定义 也为将来筛选广谱小分子抑制剂奠定了基础。 ATS。

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.