Fig 7.

Schematic diagram for the role of Pfn1 under STS condition. Pfn1 overexpression increases actin filament assembly and then enhances the binding among Pfn1, actin and integrin β1, which form a more stable complex on the plasma membrane. The co-administration of them in such cells leads to retention of integrin β1 on the membrane, thus inhibiting its degradation by proteosome. The up-regulated integrin β1 involves in apoptotic susceptivity facilitated by Pfn1 overexpression. The increased integrin α5β1 receptor by Pfn1 overexpression is excess to fibronectin as an extracellular ligand. Accordingly, the ligation state of the integrin α5β1 molecule with FN influenced by ectopic Pfn1 accounts for the cell apoptotic sensitivity under STS treatment.