Fig. 4. Steady-state levels of E6-AP mRNA are unchanged, whereas the levels of E6-AP protein are increased in both revertants compared with HeLa cells. A, Northern blot analysis of total RNA extracted from HeLa, HA, and HF. The filter was probed with 32P-labeled E6-AP cDNA. B, ethidium bromide-stained membrane used for E6-AP mRNA detection. C, Western blot analysis of cellular lysates probed with anti-E6-AP polyclonal antibody.