ATP-association to intrabacterial nanotransportation system in Vibrio cholerae

Med Mol Morphol. 2015 Dec;48(4):225-34. doi: 10.1007/s00795-015-0105-4. Epub 2015 May 19.

Abstract

Vibrio cholerae colonizes the lumen of the proximal small intestine, which has an alkaline environment, and secretes cholera toxin (CT) through a type II secretion machinery. V. cholerae possesses the intrabacterial nanotransportation system (ibNoTS) for transporting CT from the inner portion toward the peripheral portion of the cytoplasm, and this system is controlled by extrabacterial pH. Association of ATP with ibNoTS has not yet been examined in detail. In this study, we demonstrated by immunoelectron microscopy that ibNoTS of V. cholerae under the extrabacterial alkaline condition was inhibited by ATP inhibitors, 2,4-dinitrophenol (DNP), a protonophore, or 8-amino-adenosine which produces inactive form of ATP. The inhibition of CT transport can be reversed by neutralization of DNP. Those inhibitions were associated with decrease of CT secretion by which ibNoTS followed. We propose that ATP closely associates with V. cholerae ibNoTS for transporting CT.

Keywords: ATP; Cholera toxin; Immunoelectron microscopy; Nanotransportation; Vibrio cholerae.

MeSH terms

  • 2,4-Dinitrophenol / pharmacology
  • Adenosine / analogs & derivatives*
  • Adenosine / pharmacology
  • Adenosine Triphosphate / antagonists & inhibitors
  • Adenosine Triphosphate / metabolism*
  • Biological Transport / drug effects
  • Cholera Toxin / metabolism*
  • Cytoplasm / metabolism
  • Humans
  • Hydrogen-Ion Concentration
  • Intestine, Small / microbiology
  • Microscopy, Immunoelectron
  • Type II Secretion Systems / drug effects*
  • Uncoupling Agents / pharmacology
  • Vibrio cholerae / metabolism*

Substances

  • Type II Secretion Systems
  • Uncoupling Agents
  • 8-aminoadenosine
  • Adenosine Triphosphate
  • Cholera Toxin
  • Adenosine
  • 2,4-Dinitrophenol