Open AccessLysine Decarboxylase Expression by Vibrio vulnificus Is Induced by SoxR in Response to Superoxide Stress
Author(s) -
Ju-Sim Kim,
Sang Ho Choi,
Chang Kyu Lee
Publication year - 2006
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.01084-06
Subject(s) - lysine decarboxylase , cadaverine , vibrio vulnificus , biology , superoxide , superoxide dismutase , biochemistry , lysine , oxidative stress , operon , vibrio parahaemolyticus , putrescine , escherichia coli , enzyme , gene , bacteria , amino acid , genetics
Lysine decarboxylase expression byVibrio vulnificus , which is up-regulated by CadC in response to acid stress, is also induced by SoxR in response to superoxide stress. SoxR binds to the promoter region of thecadBA operon, coding for a lysine-cadaverine antiporter (CadB) and a lysine decarboxylase (CadA). The induction ofcadBA transcription by SoxR is independent of CadC. Cadaverine, which neutralizes the external medium, also appears to scavenge superoxide radicals, since increasing cellular cadaverine by elevating the gene dosage ofcadBA significantly diminished the induction of Mn-containing superoxide dismutase under methyl viologen-induced oxidative stress. Consistently, a lack of cadaverine caused by mutation incadA resulted in low tolerance to oxidative stress compared with that of the wild type.