High Glucose Induces Sumoylation of Smad4 via SUMO2/3 in Mesangial Cells
Figure 4
Smad4 is sumoylated by SUMO2/3 in mesangial cells. (a) and (b) Cell lysates were subjected to immunoprecipitation (IP) with anti-Smad4 antibody or normal mouse IgG as a negative control, followed by immunoblot (IB) with anti-SUMO2/3 or anti-SUMO1 antibody to detect the interaction between SUMO2/3 or SUMO1 with Smad4. The arrow marked band indicates SUMO2/3-Smad4 conjugates (a). No specific band was detected for SUMO1-Smad4 conjugates in mesangial cells (b). IgG-H marks the IgG heavy chain in (a) and (b). (c) Cells were treated with 5.6 mmol/L and 20 mmol/L glucose and equimolar concentration of mannitol for 24 h. Anti-Smad4 immunoprecipitates were subjected to immunoblotting with anti-Smad4 or anti-SUMO2/3 antibodies for Smad4 and SUMO2/3-Smad4 proteins. Relative expression of SUMO2/3-Smad4 conjugates was detected by Western blot and normalized to Smad4. compared to normal control; compared to mannitol control.
