Fig 3. Phorbol 12-myristate 13-acetate (PMA)–induced dissociation of Hsp27 is suppressed partially by an inhibitor of p38 MAP kinase and completely by inhibitors of protein kinase C. Cells were exposed to 1 μM PMA at 37°C for 90 minutes with or without 10 μM PD 169316 (PD16), 10 μM PD 98059 (PD98), 10 μM Uo 126 (Uo), 100 nM staurosporine (STP), 5 μM bisindolylmaleimide I (BIM), or 5 μM Go 6983 (Go). Each cell extract was subjected to sucrose density gradient centrifugation, and the concentrations of Hsp27 were determined as described in the caption to Figure 1. Control, untreated cells. The data are representative of 2 separate experiments