Cytoskeleton-modulating effectors of enteropathogenic and enterohemorrhagic Escherichia coli: role of EspL2 in adherence and an alternative pathway for modulating cytoskeleton through Annexin A2 function.
Enterohemorrhagic Escherichia coli (EHEC) and enteropathogenic Escherichia coli (EPEC) are attaching/effacing pathogens that possess a type III secretion system and deliver a variety of effectors into host cells for successful infection. EHEC produces at least 20 effector families with various functions. Reorganization of the cellular cytoskeleton at the adherent site is a hallmark of these pathogens. EspL2 of EHEC is a novel effector class that can modulate the cellular cytoskeleton. By interacting with and activating Annexin A2, EspL2 contributes to the formation of a condensed microcolony and may adhere to host cells in a translocated intimin receptor-independent manner. The interaction of EspL2 with Annexin A2 increases F-actin bundling activity and strengthens the membrane-cytoskeleton linkage, resulting in the condensation of actin fibers and the induction of a pseudopod-like structure. Membrane microdomains, namely the lipid raft, which is rich in Annexin A2, may be a platform by which EHEC/EPEC infection modulates cellular signaling and the cytoskeleton.
Tobe
Toru
T
Department of Microbiology and Immunology, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan. torutobe@bact.med.osaka-u.ac.jp
D000199:Actins / Q000378:metabolism; D017306:Annexin A2 / Q000502:physiology*; D002118:Calcium / Q000502:physiology; D018797:Cell Cycle Proteins / Q000502:physiology; D003599:Cytoskeleton / Q000382:microbiology / Q000473:pathology; D010450:Endopeptidases / Q000502:physiology; D054324:Enterohemorrhagic Escherichia coli / Q000235:genetics / Q000472:pathogenicity*; D054308:Enteropathogenic Escherichia coli / Q000235:genetics / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000473:pathology* / Q000503:physiopathology; D029968:Escherichia coli Proteins / Q000235:genetics / Q000502:physiology; D005798:Genes, Bacterial; D006463:Hemolytic-Uremic Syndrome / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D021962:Membrane Microdomains / Q000502:physiology; D005810:Multigene Family; D064247:Separase; D015398:Signal Transduction
D000199:Actins; D017306:Annexin A2; D018797:Cell Cycle Proteins; D029968:Escherichia coli Proteins; D010450:Endopeptidases; D064247:Separase; D002118:Calcium