Fig. 4: Testosterone stimulation of quorum sensing requires the histidine kinase AgrC.
From: Skin androgens regulate Staphylococcus aureus pathogenicity via quorum sensing
a, S. aureus wild-type (HG003::lux) and mutant constitutive bioluminescent reporter strains (ΔagrBD::lux and ΔagrC::lux) treated with 10 nM testosterone (n = 3). Bioluminescence is recorded every hour using a plate reader. Statistics of HG003 compared with ΔagrC treated with testosterone. Means ± s.e.m. (error bars) are plotted. #P < 0.0001 by 2-way ANOVA. b,c, ΔagrC mutant and ΔagrC-complemented strains (ΔagrC-comp. AgrC) treated with 10 nM testosterone, DHT, AIP-I or untreated (n = 3). Relative psmα expression (b) and percentage of bacterially induced haemolysis (c) (n = 4) technical replicates are shown; RBCs are from a single donor. Means ± s.e.m. (error bars) are plotted. *P < 0.05, **P < 0.01, ***P < 0.001, by 1-way ANOVA. d, Male wild-type mice (n = 5) were epicutaneously infected with bioluminescent MRSA SAP430 (MRSA::lux, 1 × 106 CFU) or AgrC-histidine-kinase-deficient (ΔagrC::lux) S. aureus (n = 6). An aggregate from two experiments is shown. Representative bioluminescence is shown. Means ± s.e.m. (error bars) are plotted. **P < 0.01 by 2-way ANOVA. e, Male wild-type mice were infected with ΔagrC::lux (1 × 106 CFU, 3 days), treated with testosterone (n = 5), AIP-I (n = 5) or vehicle control (n = 5). Means ± s.e.m. (error bars) are plotted. NS by two-way ANOVA compared with vehicle control. f, The predicted dimeric structure of AgrC bound to AIP-I and testosterone shown as a rainbow-coloured ribbon (blue to red, amino to carboxy terminus), with the catalytic ATP-binding (CA) and dimerization/histidine phosphotransfer (DHp) domains. Testosterone, AIP-I and ATP are depicted as spheres (nitrogen, blue; oxygen, red; sulfur, yellow; phosphorus, orange; carbon, orange, purple and green for AIP-I, testosterone and ATP, respectively). The polar side chains of residues T141 (helix α6), T190, S194, T197 and S201 (helix α8) are shown. Enlarged insert: highest-affinity docking solution of testosterone is shown. See Extended Data Fig. 7i–n.
