Open AccessCarbon source control of the phosphorylation state of the B acillus subtilis carbon‐flux regulator C rh in vivo
Author(s) -
Landmann Jens J.,
Werner Susanne,
Hillen Wolfgang,
Stülke Jörg,
Görke Boris
Publication year - 2012
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2011.02456.x
Subject(s) - phosphorylation , pep group translocation , bacillus subtilis , biochemistry , kinase , chemistry , protein phosphorylation , biology , protein kinase a , microbiology and biotechnology , enzyme , phosphoenolpyruvate carboxykinase , bacteria , genetics
B acillus subtilis possesses carbon‐flux regulating histidine protein ( C rh), a paralog of the histidine protein ( HP r) of the phosphotransferase system ( PTS ). Like HP r, C rh becomes (de)phosphorylated in vitro at residue S er46 by the metabolite‐controlled HP r kinase/phosphorylase HP r K / P . Depending on its phosphorylation state, C rh exerts regulatory functions in connection with carbohydrate metabolism. So far, knowledge on phosphorylation of C rh in vivo has been limited and derived from indirect evidence. Here, we studied the dynamics of C rh phosphorylation directly by non‐denaturing gel electrophoresis followed by W estern analysis. The results confirm that HP r K / P is the single kinase catalyzing phosphorylation of C rh in vivo . Accordingly, phosphorylation of C rh is triggered by the carbon source as observed previously for HP r, but with some differences. Phosphorylation of both proteins occurred during exponential growth and disappeared upon exhaustion of the carbon source. During exponential growth, ~ 80% of the C rh molecules were phosphorylated when cells utilized a preferred carbon source. The reverse distribution, i.e. around 20% of C rh molecules phosphorylated, was obtained upon utilization of less favorable substrates. This clear‐cut classification of the substrates into two groups has not previously been observed for HP r( S er)~ P formation. The likely reason for this difference is the additional PTS ‐dependent phosphorylation of HP r at H is15, which limits accumulation of HP r( S er)~ P .