Figure 7.

RNase E-dependent degradation of CyaR by ArcZ. (A) MCE+ (rne⁺) and MCE- (rne^ts) cells were transformed with pArcZ. IPTG was added 4 h after a 1/100 dilution of culture (grown at 30°C), and the culture was further incubated for 15 min. Cultures were heat-shocked for 15 min at 42°C or incubated for 15 min at 30°C. Total cellular RNA was prepared from the cultures, and cellular levels of CyaR were measured by Northern blot analysis using an anti-CyaR oligonucleotide probe; 5S rRNA was detected as a loading control. (B) The rne⁺ and rne^ts cells were transformed with pCyaR. ArcZ levels were analysed as described in (A). Bar graphs show fold changes of ArcZ transcripts (ArcZ_f and ArcZ_s) compared with vector controls at 30°C.