Figure 4
From: Escherichia coliYmdB regulates biofilm formation independently of its role as an RNase III modulator
Regulation of RpoS levels and activity by YmdB. (A) Effect of YmdB on in vivo expression levels of RpoS. KS004 [SG30013 (λRpoS750::LacZ] [31] strains containing either pCA24N (−gfp) or ASKA-ymdB (−) were grown to OD600 = 0.2, induced by IPTG (0.1 mM final), and further grown to OD600 = 1.0. Aliquots were then assayed for β-galactosidase activity. Data represent the mean values from n = 3 experiments (p = 0.05). (B) Expression level of RpoS. Total lysates prepared from the cell described in (A) and from Keio-∆rpoS cells were immunoblotted antibodies against RpoS and S1. The Keio-∆rpoS strain is included to show the specificity of the antibody. The relative levels of RpoS normalized against S1 protein are shown. ND, not determined. (C) Determination of steady-state levels of rpoS transcript induced by YmdB. cDNA synthesized from total RNA obtained from BW25113, KSK002 (∆ymdB), KSK001 (rnc14) or BW25113 cells containing either pCA24N (−gfp) or ASKA-ymdB (−) were qPCR amplified using the rpoS- or 16S RNA-specific primer sets listed in Additional file 1: Table S2 and then compared. Data represent the mean values from triplicate experiments.