FIGURE 2.

TDG sumoylation and SUMO binding are not essential for 5caC repair. A, schematic diagram of TDG and the location of the C-terminal SIM and sumoylation site at Lys³³⁰. B, cells were co-transfected with expression vectors for TET_CD and varying levels of wild type TDG (TDG), or sumoylation (TDG_K330R) or SUMO binding (TDG_E310Q) mutant TDG. Protein and 5caC levels were monitored by immunoblot analysis. ** indicates sumoylated TDG. Protein and DNA loading were assessed by tubulin and methylene blue staining, respectively. C, analysis of wild type and mutant TDG localization by immunofluorescence microscopy. The cells were transfected with plasmids coding for FLAG-tagged wild type TDG or sumoylation or SUMO binding TDG mutants. TDG localization was assessed using anti-FLAG antibodies. Localization to PML nuclear bodies was assessed by co-localization with SUMO1. Bar, 5 μm.