Figure 8.

The inhibition of c‐di‐AMP production by glutamine and ammonium is independent of GdpP and YbbR. (a, b) Cellular c‐di‐AMP levels. (a) S. aureus strains LAC* (WT) and LAC*gdpP::kan (gdpP::kan) were grown in GDM or in GDM containing glutamine (GDM + Gln) or ammonium (GDM + NH₃). Cell extracts were prepared, and c‐di‐AMP concentrations measured using a competitive ELISA assay. The average values and SDs from three biological replicates were plotted as ng c‐di‐AMP/ mg protein. For statistical analysis one‐way ANOVAs followed by Dunnett's multiple comparison tests were performed to identify statistically significant differences between the different media as compared to the GDM medium (n.d. = not determined. Statistical analysis was not performed due to values being below our detection limit; these values were set to 0, ** = p < .001, *** = p < .0001). (b) Same as in (a) but using S. aureus strains LAC* (WT) and LAC*ΔybbR (ΔybbR)