FIG 3.
CtrA stability is regulated during exponential growth in a CbrA-dependent manner. (A and B) Western blots of whole-cell lysates were probed with anti-CtrA and anti-ClpP. Lane 1 contains purified S. meliloti CtrAHIS. In lanes 2 to 9, the levels of protein were assayed by Western blotting at different times (0, 30, 120, and 240 min) after treatment of cells with (+) and without (−) chloramphenicol (CHL). (C and D) CtrA signal in wild-type (WT) and ΔcbrA cells was first normalized to the ClpP loading control signal and then independently normalized to 1 using their value at 0 min. Graphical results are the averages for at least three biological replicates, and error bars represent the standard deviations. Solid line, no-chloramphenicol control; broken line, chloramphenicol treatment. The value that was significantly different from the value for the no-chloramphenicol control (P < 0.0001) is indicated by an asterisk.