ErbB4 ICD is deSUMOylated by SENP1, SENP2, and SENP5.
A, COS-7 cells were transfected with HA-tagged ErbB4 ICD, His6-tagged SUMO1, and FLAG-tagged wild-type or C603A mutant SENP1 as indicated. Cells were lysed in denaturing buffer, and lysates were incubated with Ni2+-NTA agarose to pull down His6-SUMO conjugates. Whole cell extracts or pulldown samples were analyzed by Western blotting with anti-ErbB4. SENP1 expression was analyzed by Western blotting with anti-FLAG. B, COS-7 cells were transfected with HA-tagged ErbB4 ICD, His6-SUMO1, or His6-SUMO3 and FLAG-tagged SENP1 or SENP2 as indicated, and analyzed as in A. C, COS-7 cells were transfected as indicated with HA-tagged ErbB4 ICD, His6-SUMO3, and FLAG-tagged SENP1, SENP2, SENP6, or SENP7 or GFP-tagged SENP3 or SENP5, and analyzed as in A. The effect of each SENP on deSUMOylation of ErbB4 ICD was analyzed in three to six independent experiments.