Schweppe Devin K, Harding Christopher, Chavez Juan D, Wu Xia, Ramage Elizabeth, Singh Pradeep K, Manoil Colin, Bruce James E
Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA 98195, USA.
Departments of Medicine and Microbiology, University of Washington School of Medicine, Seattle, WA 98195, USA.
Chem Biol. 2015 Nov 19;22(11):1521-1530. doi: 10.1016/j.chembiol.2015.09.015. Epub 2015 Nov 5.
Interspecies protein-protein interactions are essential mediators of infection. While bacterial proteins required for host cell invasion and infection can be identified through bacterial mutant library screens, information about host target proteins and interspecies complex structures has been more difficult to acquire. Using an unbiased chemical crosslinking/mass spectrometry approach, we identified interspecies protein-protein interactions in human lung epithelial cells infected with Acinetobacter baumannii. These efforts resulted in identification of 3,076 crosslinked peptide pairs and 46 interspecies protein-protein interactions. Most notably, the key A. baumannii virulence factor, OmpA, was identified as crosslinked to host proteins involved in desmosomes, specialized structures that mediate host cell-to-cell adhesion. Co-immunoprecipitation and transposon mutant experiments were used to verify these interactions and demonstrate relevance for host cell invasion and acute murine lung infection. These results shed new light on A. baumannii-host protein interactions and their structural features, and the presented approach is generally applicable to other systems.
种间蛋白质-蛋白质相互作用是感染的重要介质。虽然可以通过细菌突变文库筛选来鉴定宿主细胞侵袭和感染所需的细菌蛋白质，但有关宿主靶蛋白和种间复合物结构的信息却更难获得。我们采用一种无偏向性的化学交联/质谱方法，鉴定了感染鲍曼不动杆菌的人肺上皮细胞中的种间蛋白质-蛋白质相互作用。这些工作鉴定出了3076个交联肽对和46种种间蛋白质-蛋白质相互作用。最值得注意的是，鲍曼不动杆菌的关键毒力因子OmpA被鉴定为与参与桥粒的宿主蛋白交联，桥粒是介导宿主细胞间黏附的特殊结构。通过免疫共沉淀和转座子突变实验来验证这些相互作用，并证明其与宿主细胞侵袭和急性小鼠肺部感染的相关性。这些结果为鲍曼不动杆菌与宿主蛋白的相互作用及其结构特征提供了新的线索，并且所提出的方法普遍适用于其他系统。
