Enteropathogenic E. coli effectors EspG1/G2 disrupt tight junctions: new roles and mechanisms.
Enteropathogenic E. coli (EPEC) infection is a major cause of infantile diarrhea in the developing world. Using a type-three secretion system, bacterial effector proteins are transferred to the host cell cytosol where they affect multiple physiological functions, ultimately leading to diarrheal disease. Disruption of intestinal epithelial cell tight junctions is a major consequence of EPEC infection and is mediated by multiple effector proteins, among them EspG1 and its homologue EspG2. EspG1/G2 contribute to loss of barrier function via an undefined mechanism that may be linked to their disruption of microtubule networks. Recently new investigations have identified additional roles for EspG. Sequestration of active ADP-ribosylating factor (ARF) proteins and promotion of p21-activated kinase (PAK) activity as well as inhibition of Golgi-mediated protein secretion have all been linked to EspG. In this review, we examine the functions of EspG1/G2 and discuss potential mechanisms of EspG-mediated tight junction disruption.
Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA.
Lila G
LG
Glotfelty
Gail A
GA
Hecht
D004926:Escherichia coli / Q000502:physiology*; D029968:Escherichia coli Proteins / Q000502:physiology*; D008869:Microtubule-Associated Proteins; D019108:Tight Junctions
D029968:Escherichia coli Proteins; C000599182:EspG1 protein, E coli; C505458:EspG2 protein, E coli; D008869:Microtubule-Associated Proteins