Effects of constitutively active MEKK-1 on PAI-1 promoter activity in VSMCs. A series of deletional PAI-1 promoter/Luciferase constructs, PAI-1(-1800)/Luc, PAI-1(-764)/Luc, PAI-1(-219)/Luc, PAI-1(-88)/Luc, PAI-1(-65)/Luc, PAI-1(-50)/Luc, and PAI-1(-22)/Luc, were cotransfected into VSMCs with pCDNA3.1 blank vector or with MEKK-1^*. To examine if the activities of MEK1,2 or p38 were required in MEKK-1 stimulation, cells were treated with 50 μM PD98059 (PD) or 5 μM SB203580 (SB) 6 hours after the start of transfection. Renilla luciferase activities of cotransfected pRL-TK were used to normalize transfection efficiency. All transfections were performed in triplicate, and bar graph shows results from 3 or more separate experiments.