FIG 1.

Effect of environmental signals and csrS mutations on CsrR phosphorylation. (A) Representative Western immunoblot for CsrR for GAS lysates separated by electrophoresis on a 10% Phos-tag polyacrylamide gel. Strains tested were wild-type GAS 854, CsrS phosphatase mutant T284A, and CsrS kinase mutant H280A, all grown in unsupplemented liquid medium (THY) or medium supplemented with 300 nM LL-37 or 15 mM MgCl₂. CsrR∼P denotes phosphorylated CsrR protein. (B) Densitometric quantification of the percentage of total CsrR represented by CsrR∼P in the indicated strains and growth conditions. Values represent means ± standard errors of the means (SEM) of data from three independent experiments.