FIG. 7.

IP-in-gel kinase assay (using different antibodies for IP of protein kinases) of reactivity with Hsp27. Wild-type (wt), MK2- and MK5-deficient MEFs were stimulated for 45 min with 250 μM arsenite (lanes A) or 100 nM phorbol myristate acetate (lanes P) or left untreated (lanes C). Cells were lysed, kinases were immunoprecipitated by (A) MK5-specific antibodies (8), (B) MK2-specific antibodies (3), or (C) anti-PRAK antibodies, and Hsp27 kinase activity was monitored by an in-gel kinase assay (10, 27).