Figure 11.

Effect of mutating activation loop phosphorylation sites on kinase activity. (A) Mutations of S⁶⁶³, S⁶⁷⁰, S⁶⁷², T⁶⁸¹ to Ala and Y⁶⁸⁴ to Phe (B) Mutations of S⁶⁶³, S⁶⁷⁰, S⁶⁷², T⁶⁸¹ to Asp and Y⁶⁸⁴ to Asp, Ser and Thr. Each mutant was purified and subjected to in vitro kinase assay as described in Materials & Methods. Equal amounts of recombinant proteins were loaded and separated by SDS-PAGE followed by autoradiography. In A and B, the top panel shows the autoradiogram and the bottom panel the corresponding Coomassie Blue stained gel. Wild type JKC and the mutant, JKC2m, were used as controls.