RIP and anti-sigma E signaling pathways are involved in RpoE-regulated QS.

Abstract

<p>(<b>A</b>) HPA digestion assays were performed to analyze extracellular Asp activity in wt and mutant strains. Bacteria were centrifuged after they were cultured in LBS medium for 9 h at various temperatures. The supernatants were harvested, and protease activity was measured. ECP activities were normalized by dividing the total level of activity by the cell density for each strain. The results are shown as the mean ± S.D. (<i>n</i> = 3). * <i>P</i> <0.05, ** <i>P</i> <0.01, <i>t-</i>test compared to the corresponding results in the wt strain at each temperature. (<b>B</b>) Western blot analysis was performed to determine the distribution of RpoE in membrane and cytoplasmic pellets in wt, Δ<i>degS</i> and Δ<i>rseA</i>^20-39 strains at different temperatures. Bacterial cells were centrifuged after they were cultured in LBS medium for 9 h, and the cytoplasmic and membrane protein pellets were then extracted. RNAP was used as a loading control.</p