FIG 5.
The ClpXP protease is responsible for the cell cycle oscillation of CckN and PleC. (a) Immunoblotting of protein samples extracted from synchronized cckN-3FLAG (RH1881) or 3FLAG-cckN (RH1929) cells to follow CckN, CtrA, and MreB abundance throughout the cell cycle. The times at which the samples were withdrawn after synchrony are indicated in minutes. (b) The relative abundance of CckN-3FLAG, PleC, and CtrA was measured in wild-type (RH50 or RH1881), ΔsocAB (RH1671 or RH737), ΔsocAB ΔclpP (RH2279 or RH1063), ΔsocAB ΔclpX (RH1674 or RH995), ΔclpA (RH864 or RH1093), Δlon (RH2472 or RH1228), ΔhslV (RH864 or RH1247), ΔftsH (RH865 or RH1229), ΔcpdR (RH339 or RH1133), ΔrcdA (RH323 or RH1149), and ΔpopA (RH315 or RH1151) strains. Means were statistically compared using a two-way ANOVA, followed by Dunnett’s multiple-comparison test; ns, not significant; **, P < 0.01; ****, P < 0.0001. (c) The relative abundance of CckN-3FLAG and PleC and CtrA was measured in wild-type (RH1881), 3FLAG-cckN (RH1929), cckNAA::DD-3FLAG (RH1576), and pleCAA::DD (RH2548) strains grown in complex medium (PYE) and normalized to the corresponding WT (100%). Error bars indicate SD; n = 3. Means were statistically compared using a one-way ANOVA, followed by Sidak’s multiple-comparison test; ns, not significant; ****, P < 0.0001. Only significant differences are indicated on the graph.