Fig. 6.

DNA damage inhibits MDM2 dimerization in vivo. (a) The C-terminal region (residues 362 to 491) of wild-type MDM2, MDM2-6A, and MDM2-6D were fused to YFP N- and C-terminal fragments. (b) Each pair of YFP N- and C-terminal fusion proteins were cotransfected into U2OS cells, counterstained with 4B11, and analyzed for the ratio of YFP-positive to MDM2-positive cells. DNA damage was induced with NCS at 50 nM for 10 h. The data represent the averages of three experiments. (c) Representative photographs of YFP fluorescence signal in U2OS cells cotransfected with control YFP N/C fragments or YFP N/C fragments fused to the MDM2 RING domain.