FIG 2 .

Activation of JNK requires SLO and is enhanced by pore formation. (A) HeLa cells were infected with the indicated strains for 5 h, and activation of several MAP kinases was assessed by Western blotting analyses of cellular lysates to detect their phosphorylated forms. Two isoforms exist for JNK and ERK. Lysates were compared to uninfected cells and to cells treated with staurosporine (Stauro; 1 mM) and to actin. (B) Activation of JNK was assessed by Western blotting following infection by various S. pyogenes strains expressing NADase⁺ or NADase⁻ SPN in combination with wild-type (WT), monomer-locked (Mono), or prepore-locked (8) SLO mutants, as indicated below the gels. (C) Western blot analysis of JNK activation in HeLa cells following a 30-min exposure to the indicated concentrations of purified SLO. Blots presented are representative of at least 3 independent experiments. The molecular masses of the various proteins detected are on the right, in kilodaltons.