Fig. 4.

CDK-mediated NHERF-1 phosphorylation is required for its degradation induced by HPV16 E6. (A) HFKs expressing HPV16 E6 and E7 were treated with the CDK inhibitor roscovitine at the indicated concentrations, and NHERF-1 protein levels were determined by SDS-PAGE and immunoblotting. (B) HFKs expressing HPV16 E6 were transfected with pLXSN expressing His-NHERF-1, together with increasing concentrations of pLSXN expressing HPV16 E7, wild type or the glycine 24 mutant (G24), as indicated. After 24 h, protein extracts were analyzed by immunoblotting (top), and the intensities of the protein bands were quantified (bottom).