FIG. 5.

The EGFP-E6 fusion protein is nuclear localized and degrades wild-type p53. HaCaT cells were transfected with pEGFP (A) or pEGFP-E6 (B), and the localization of the protein was visualized by fluorescence microscopy. Whereas EGFP was present in the cytoplasm, EGFP-E6 (B) was exclusively localized to the nucleus. Bar, 10 μm. The functional activity of EGFP-E6 was established by determining its ability to mediate p53 degradation in a wild-type p53 cell line. (C) p53 expression, measured by Western blotting, was reduced in K1neo cells transfected with pEGFP-E6 compared to cells transfected with pEGFP. Actin expression was shown to confirm equivalent loading of protein in both samples.