Taylor K A, O'Connell C B, Luther P W, Donnenberg M S
Division of Infectious Diseases, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA.
Infect Immun. 1998 Nov;66(11):5501-7. doi: 10.1128/IAI.66.11.5501-5507.1998.
The EspB protein of enteropathogenic Escherichia coli (EPEC) is exported via a type III secretion apparatus. EspB is critical for signaling the host cell and for the development of the attaching and effacing lesion characteristic of EPEC infection. We used cellular fractionation and confocal laser scanning microscopy to determine the cellular location of EspB during infection of HeLa cells. Both methods indicated that EspB is targeted to the cytoplasm of infected cells. Using mutants, we found that EspB targeting to the host cell cytoplasm requires the type III secretion apparatus and the secreted proteins EspA and EspD, but not intimin. These results provide insights into the function of the type III secretion apparatus of EPEC and the functions of the Esp proteins.
肠致病性大肠杆菌（EPEC）的EspB蛋白通过III型分泌装置输出。EspB对于向宿主细胞发出信号以及形成EPEC感染特有的黏附和损毁性损伤至关重要。我们使用细胞分级分离和共聚焦激光扫描显微镜来确定在HeLa细胞感染过程中EspB的细胞定位。两种方法均表明EspB定位于被感染细胞的细胞质中。利用突变体，我们发现EspB定位于宿主细胞质需要III型分泌装置以及分泌蛋白EspA和EspD，但不需要紧密黏附素。这些结果为EPEC的III型分泌装置的功能以及Esp蛋白的功能提供了见解。
