Fig. 4.

Endogenous GTP levels are required for glucose-induced Rac1 activation and subsequent ROS generation in pancreatic β-cells. INS 832/13 cells were incubated overnight with either diluent or mycophenolic acid (MPA; 10 μM), followed by stimulation with either LG (5 mM) or HG (20 mM) for 30 min. The degree of Rac1 activation was determined by p21-activated kinase-binding domain (PAK-PBD) pull-down assay, as described in materials and methods. A representative blot from two pull-down assays yielding similar data is depicted here.