FIG 3.

E1 assembles as a ternary complex with UAF1 and associated USPs. (A) Coimmunoprecipitation of YFP-E1 with 3F-UAF1 and RFP-USP1, RFP-USP12, or RFP-USP46. YFP-E1, as either the wild-type (WT) protein or the UAF1-binding-defective VE protein as a control, was immunoprecipitated at 48 h posttransfection using an anti-GFP antibody from cells transfected with the indicated expression vectors. Immunoprecipitates were analyzed by Western blotting with anti-RFP (for USPs), anti-Flag (for UAF1), or anti-GFP (for E1) antibodies. (B and C) Fluorescence confocal microscopy images showing the subcellular localization of the indicated RFP-USPs expressed either alone (B) or together with 3F-UAF1 and GFP-E1 (C). The UAF1-binding-defective E1 VE protein was used as a negative control. Nuclei were stained with DAPI.