Bovine papillomavirus oncoprotein E5 induces the NF kappa B activation through superoxide radicals.

Bovine papillomavirus type 1 (BPV-1) open reading frame E5 encodes the smallest known oncoprotein. This protein is involved in transforming cells during the early stage of infection. Nuclear factor kappa B (NF kappa B) is activated in the host cells as a result of different virus infections. It has been shown that reactive oxygen intermediates activate NF kappa B which leads the activation of several cellular genes. We studied the effect of BPV-1 ES protein on NF kappa B activation. We found that low and moderate concentrations of E5 protein activate NF kappa B. This activation is suppressed by superoxide dismutase. We conclude that the superoxide anion is involved in activation of NF kappa B.