Supplemental Material

This article contains the following supporting material:

• Materials and Methods
• Figure 1 - Tat promotes ERK1/2 activation on endothelial cells. HUVECs starved for 24 in serum free medium were stimulated with 0.5, 1 and 5 μg of Tat, or 5 μg of FN, conjugated to polystyrene beads, for 5 minutes. Tat induces ERK1/2 activation in HUVE cells already at 0.5 μg. However, a stronger ERK phosphorylation is observed at 1 and 5 μg. The bottom panel represents total ERK present in the cell lysates.

• Figure 2 - Tat promotes HUVE cell cycle progression through ERK1/2 activation. HUVECs were seeded on type I collagen and pre-incubated with 25 μM PD 98059, or 10 μM SB 203580, for 20 min. Cells were then stimulated with 10 μg/ml of Tat for 24 hr and pulsed with BrdU. A reduced percentage of cells incubated with PD 98059 and Tat entered into the S phase compared to the percentage of cells incubated with Tat and DMSO or SB 203580 and Tat.

• Figure 3 - Transfection of the kinase-dead MEK-K97M blocks ERK1/2 phosphorylation induced by Tat. EA-hy 926 cells were transfected with the kinase-dead mutant MEK-K97M or a control vector, and then incubated for 24 hr in a medium containing bFGF and Tat or BSA as negative control. The cell transfection with the kinase-dead mutant of MEK1 induced a significant block of ERK1/2 activation induced by Tat.