The c-di-GMP phosphodiesterase VmpA absent in Escherichia coli K12 strains affects motility and biofilm formation in the enterohemorrhagic O157:H7 serotype. - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Veterinary Immunology and Immunopathology Année : 2013

The c-di-GMP phosphodiesterase VmpA absent in Escherichia coli K12 strains affects motility and biofilm formation in the enterohemorrhagic O157:H7 serotype.

Priscilla Branchu
Xin Fang
  • Fonction : Auteur
Robynn Thomas
  • Fonction : Auteur
Mark Gomelsky
  • Fonction : Auteur
Laurent Claret
  • Fonction : Auteur
Josée Harel
  • Fonction : Auteur
Alain P Gobert
  • Fonction : Auteur
Christine Martin
  • Fonction : Auteur

Résumé

Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is a foodborne pathogen that resists the acidic gastric environment, colonizes the gut epithelium, and causes hemorrhagic colitis and hemolytic-uremic syndrome, especially in children. The genomic island OI-47 of E. coli O157:H7 contains a gene, z1528, encoding an EAL-domain protein potentially involved in c-di-GMP hydrolysis that is absent in non-pathogenic E. coli. This gene, designated vmpA, is co-transcribed with ycdT, which is present in non pathogenic E. coli and encodes a diguanylate cyclase involved in c-di-GMP synthesis. To test for vmpA function, we constructed a vmpA knockout mutant. We also overexpressed vmpA, purified the VmpA protein and assayed for its activity in vitro. We found that VmpA possesses c-di-GMP phosphodiesterase activity and that the vmpA mutation results in increased biofilm formation, and reduced swimming motility, which is consistent with the function determined in vitro. Unexpectedly, suppressor mutations arise frequently in the vmpA background suggesting that VmpA plays an important regulatory role in E. coli O157:H7. These findings represent an example of remarkable flexibility in the organization of c-di-GMP signaling pathways in closely related species.

Dates et versions

hal-00800755 , version 1 (14-03-2013)

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Citer

Priscilla Branchu, Thomas Hindré, Xin Fang, Robynn Thomas, Mark Gomelsky, et al.. The c-di-GMP phosphodiesterase VmpA absent in Escherichia coli K12 strains affects motility and biofilm formation in the enterohemorrhagic O157:H7 serotype.. Veterinary Immunology and Immunopathology, 2013, 152 (1-2), pp.132-40. ⟨10.1016/j.vetimm.2012.09.029⟩. ⟨hal-00800755⟩

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