Real-time analysis of effector translocation by the type III secretion system of enteropathogenic Escherichia coli.

Abstract

Bacteria use type III secretion systems (TTSS) to translocate effector proteins into host cells. Better understanding of the TTSS and its effectors' functions will require assays to measure their activities in vivo and in real time. We designed a real-time, high-throughput translocation assay that utilizes fusions of effector genes to the beta-lactamase reporter gene, positioned under the effector's native promoter and chromosomal location. Using this assay, we simultaneously and quantitatively analyzed the translocation kinetics of six core enteropathogenic E. coli effectors, EspF, EspG, EspH, EspZ, Map, and Tir. A distinct order in the efficiencies of effector translocation was observed. Translocation efficiency was determined by multiple factors, including the intrabacterial effector concentration, effector-chaperone interactions, the efficiency of bacterial attachment to the host cells, and possibly also by a translocation autoinhibition mechanism. The described real-time translocation assay could be easily adapted for varied applications in the study of bacterial pathogenesis.

DOI: 10.1016/j.chom.2007.11.007
Showing 1-10 of 32 extracted citations
0501002008200920102011201220132014201520162017
Citations per Year

230 Citations

Semantic Scholar estimates that this publication has received between 87 and 496 citations based on the available data.

See our FAQ for additional information.