A C-terminal class I PDZ binding motif of EspI/NleA modulates the virulence of attaching and effacing Escherichia coli and Citrobacter rodentium.
Enteropathogenic Escherichia coli induces characteristic attaching-effacing (A/E) lesions on the intestinal mucosa during infection. The locus of enterocyte effacement is essential for A/E lesion formation and encodes a type III secretion system that translocates multiple effector proteins into the host cell. Following translocation, EspI/NleA localizes to the Golgi. Using the yeast two-hybrid system (Y2HS) and PSD-95/Disk-large/ZO-1 (PDZ)-domain protein array overlays, we identified 15 putative host-interacting partners of EspI. All but two of the target proteins contained PDZ domains. Examination of the EspI amino acid sequence revealed a C-terminal consensus class I PDZ binding motif. Deletion of the last 7 amino acids of EspI to generate EspI(DeltaC7) abrogated the Y2HS interaction between EspI and 5 of the 6 putative host cell target proteins tested. Deletion of the EspI PDZ binding motif also resulted in delayed trafficking of EspI to the Golgi. Using a mouse model of infection, we showed that Citrobacter rodentium expressing truncated EspI(DeltaC7) was attenuated when in competition with C. rodentium expressing full-length EspI. Overall, these results suggested that EspI may modulate the virulence of A/E pathogens by binding host PDZ-domain proteins.
Lee
Sau Fung
SF
Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia.
Kelly
Michelle
M
McAlister
Adrian
A
Luck
Shelley N
SN
Garcia
Erin L
EL
Hall
Randy A
RA
Robins-Browne
Roy M
RM
Frankel
Gad
G
Hartland
Elizabeth L
EL
D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D044082:Citrobacter rodentium / Q000235:genetics / Q000472:pathogenicity*; D054308:Enteropathogenic Escherichia coli / Q000235:genetics / Q000472:pathogenicity*; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D015723:Gene Library; D006056:Golgi Apparatus / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D054731:PDZ Domains; D025941:Protein Interaction Mapping; D021381:Protein Transport; D020539:Sequence Analysis, Protein; D020798:Two-Hybrid System Techniques; D014774:Virulence; D037521:Virulence Factors / Q000737:chemistry / Q000235:genetics / Q000502:physiology*
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C488216:NleA protein, E coli; D037521:Virulence Factors