FIGURE 5.

MK2/3/5 inhibitor inhibits stress-induced K18/20 phosphorylation. A, HT29 cells were stimulated with 10 μg/ml anisomycin. For MK2/3 inhibition, cells were pretreated with 5 or 10 μm PHA-781089. p38 inhibitors BIRB-796 (1 μm) and SB202190 (5 μm) were used as positive controls. Phosphorylation of K20-Ser¹³, K18-Ser⁵², K8-Ser⁷³, and hHSPB1-Ser⁸² were analyzed by Western blotting. Total K20, K8/18, hHSPB1, and GAPDH were blotted to show equal loading. B, HT29 cells were stimulated with anisomycin (as in Fig. 1B) with or without treatment with 20 μm PHA-781089/5 μm SB202190. After treatment cells were fixed and double immunostained for K20 and K20-Ser(P)¹³.