Fig. 2.
Protection of wild-type NUPR1 toward degradation by thermolysin in the presence of C-RING1B. (A) Representative gels of the degradation kinetics of wild-type NUPR1 (10 μM) in the absence or presence of 45 μM (in protomer units) of C-RING1B. C-RING1B was resistant to proteolysis under our conditions (10 nM thermolysin). (B) Kinetics of degradation of wild-type NUPR1 in the absence (black symbols) or in the presence of C-RING1B [22.5 μM, red symbols; 45 μM, blue symbols, 90 μM, green symbols (all indicated in protomer units)]. Data are shown as means, and errors are SDs as obtained from three independent experiments. (C) First-order rate constants for wild-type NUPR1 degradation at different C-RING1B concentrations. (D) Plot based on a simple kinetic model to estimate the Kd value of the interaction between NUPR1 and C-RING1B. MW, molecular weight.