TY - JOUR
T1 - Temperature and Mg2+ sensing by a novel PhoP-PhoQ two-component system for regulation of virulence in Edwardsiella tarda
AU - Chakraborty, Smarajit
AU - Li, Mo
AU - Chatterjee, Chiradip
AU - Sivaraman, J.
AU - Leung, Ka Yin
AU - Mok, Yu Keung
PY - 2010/12/10
Y1 - 2010/12/10
N2 - The PhoP-PhoQ two-component system is commonly used by bacteria to sense environmental factors. Here we show that the PhoP-PhoQ system of Edwardsiella tarda detects changes in environmental temperature and Mg2+ concentration as well as regulates the type III and VI secretion systems through direct activation of esrB. Protein secretion is activated from 23 to 35°C or at low Mg2+ concentrations, but it is suppressed at or below 20°C, at or above 37°C, or at high Mg2+ concentrations. The effects of temperature and Mg2+ concentration are additive. The PhoQ sensor domain has a low Tm of 37.9°C, and it detects temperatures through a conformational change of its secondary structure. Mutation of specific Pro or Thr residues increased the stability of the PhoQ sensor drastically, altering its temperature-sensing ability. The PhoQ sensor detects Mg2+ concentration through the direct binding of Mg2+ to a cluster of acidic residues (DDDSAD) and through changes that likely affect its tertiary structure. Here, we describe for the first time the use of PhoP-PhoQ as a temperature sensor for bacterial virulence control.
AB - The PhoP-PhoQ two-component system is commonly used by bacteria to sense environmental factors. Here we show that the PhoP-PhoQ system of Edwardsiella tarda detects changes in environmental temperature and Mg2+ concentration as well as regulates the type III and VI secretion systems through direct activation of esrB. Protein secretion is activated from 23 to 35°C or at low Mg2+ concentrations, but it is suppressed at or below 20°C, at or above 37°C, or at high Mg2+ concentrations. The effects of temperature and Mg2+ concentration are additive. The PhoQ sensor domain has a low Tm of 37.9°C, and it detects temperatures through a conformational change of its secondary structure. Mutation of specific Pro or Thr residues increased the stability of the PhoQ sensor drastically, altering its temperature-sensing ability. The PhoQ sensor detects Mg2+ concentration through the direct binding of Mg2+ to a cluster of acidic residues (DDDSAD) and through changes that likely affect its tertiary structure. Here, we describe for the first time the use of PhoP-PhoQ as a temperature sensor for bacterial virulence control.
UR - http://www.scopus.com/inward/record.url?scp=78649807478&partnerID=8YFLogxK
U2 - 10.1074/jbc.M110.179150
DO - 10.1074/jbc.M110.179150
M3 - 文章
C2 - 20937832
AN - SCOPUS:78649807478
SN - 0021-9258
VL - 285
SP - 38876
EP - 38888
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 50
ER -