A negative feedback loop is critical for recovery of RpoS after stress in Escherichia coli
Fig 3
RpoS-Lac recovery from phosphate starvation depends on RpoS.
A) RpoS and RpoS-Lac stabilization during phosphate starvation in the strain SG30013, a derivative of MG1655 containing both rpoS+ in the chromosome and the RpoS-Lac translational fusion at the lacZ site. The fusion contains the full 5’ UTR of rpoS as well as 750 bp of the rpoS coding region, fused in frame to lacZ and expressed from a synthetic (Cp17) promoter. The protocol was as described in Fig 1A, a chase in which chloramphenicol was added to stop new translation. B) RpoS and RpoS-Lac degradation during recovery from phosphate starvation in the strains containing the RpoS-Lac translational fusion in the presence of RpoS (SG30013, yellow triangles), or in a strain deleted for RpoS (INH28, grey triangles); samples were taken as a function of time after chloramphenicol was added to stop translation.