TY - JOUR AU - Lilge, Lars AU - Reder, Alexander AU - Tippmann, Frank AU - Morgenroth, Friedrich AU - Grohmann, Janice AU - Becher, Dörte AU - Riedel, Katharina AU - Völker, Uwe AU - Hecker, Michael AU - Gerth, Ulf PY - 2020 M3 - Original Research TI - The Involvement of the McsB Arginine Kinase in Clp-Dependent Degradation of the MgsR Regulator in Bacillus subtilis JO - Frontiers in Microbiology UR - https://www.frontiersin.org/articles/10.3389/fmicb.2020.00900 VL - 11 SN - 1664-302X N2 - Regulated ATP-dependent proteolysis is a common feature of developmental processes and plays also a crucial role during environmental perturbations such as stress and starvation. The Bacillus subtilis MgsR regulator controls a subregulon within the stress- and stationary phase σB regulon. After ethanol exposition and a short time-window of activity, MgsR is ClpXP-dependently degraded with a half-life of approximately 6 min. Surprisingly, a protein interaction analysis with MgsR revealed an association with the McsB arginine kinase and an in vivo degradation assay confirmed a strong impact of McsB on MgsR degradation. In vitro phosphorylation experiments with arginine (R) by lysine (K) substitutions in McsB and its activator McsA unraveled all R residues, which are essentially needed for the arginine kinase reaction. Subsequently, site directed mutagenesis of the MgsR substrate was used to substitute all arginine residues with glutamate (R-E) to mimic arginine phosphorylation and to test their influence on MgsR degradation in vivo. It turned out, that especially the R33E and R94/95E residues (RRPI motif), the latter are adjacently located to the two redox-sensitive cysteines in a 3D model, have the potential to accelerate MgsR degradation. These results imply that selective arginine phosphorylation may have favorable effects for Clp dependent degradation of short-living regulatory proteins. We speculate that in addition to its kinase activity and adaptor function for the ClpC ATPase, McsB might also serve as a proteolytic adaptor for the ClpX ATPase in the degradation mechanism of MgsR. ER -