Cadaverine is transported into Vibrio vulnificus through its CadB in alkaline environment.
The exogenously-added cadaverine is effective in protecting Vibrio vulnificus from methyl viologen (MV)-induced superoxide stress at pH 8.5. Such a protective effect by cadaverine was not observed at pH 7.5. Consistently, the accumulated level of intracellular cadaverine at pH 8.5 is approximately four times as much as that of the control cell at pH 7.5. Cadaverine accumulation is not affected by MV. The protection of V. vulnificus by cadaverine from superoxide stress was abolished when cadB coding for lysine-cadaverine antiporter was interrupted. However, the cadaverine-mediated protection was complemented with cadB DNA. Therefore, CadB of V. vulnificus not only acts as a lysine-cadaverine antiporter at acid pH to neutralize the external medium but also mediates cadaverine uptake at alkaline pH to result in cell protection from superoxide stress.
Kang
In-Hye
IH
Department of Life Science and Basic Science Institute for Cell Damage Control, Sogang University, Seoul 121-742, Korea.
Kim
Eui-Jin
EJ
Lee
Jeong K
JK
D000468:Alkalies / Q000494:pharmacology*; D026905:Amino Acid Transport Systems / Q000235:genetics / Q000378:metabolism*; D017920:Antiporters / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport / Q000187:drug effects; D002103:Cadaverine / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D010269:Paraquat / Q000494:pharmacology; D041261:Vibrio vulnificus / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*
D000468:Alkalies; D026905:Amino Acid Transport Systems; D017920:Antiporters; D001426:Bacterial Proteins; C088101:CadB protein, Bacteria; D002103:Cadaverine; D010269:Paraquat