The EspB protein of enteropathogenic Escherichia coli is targeted to the cytoplasm of infected HeLa cells.
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.
Division of Infectious Diseases, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA.
K A
KA
Taylor
C B
CB
O'Connell
P W
PW
Luther
M S
MS
Donnenberg
D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism* / Q000382:microbiology; D004926:Escherichia coli / Q000378:metabolism / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000378:metabolism* / Q000382:microbiology; D029968:Escherichia coli Proteins; D005260:Female; D006367:HeLa Cells; D006801:Humans; D018613:Microscopy, Confocal; D013347:Subcellular Fractions / Q000378:metabolism / Q000382:microbiology
D001425:Bacterial Outer Membrane Proteins; C087863:EaeB protein, E coli; D029968:Escherichia coli Proteins