Human papillomavirus type 16 E5 protein

Abstract

AbstractThe E5 protein of human papillomaviruses is considered to be an oncogene with weak transforming properties, contrary to the bovine papillomavirus E5 protein. A role in potentiating the effects of the main E7 and E6 oncogenes has been proposed for the E5 protein. Because deletion of the E5 sequence may take place upon integration of viral DNA into the host chromosome, early function(s) in the neoplastic process was long proposed for the E5 protein. E5 expression seems to enhance cellular response to growth factors and, consequently,activation of mitogenic signalling, leading to increased cell proliferation. It also reduces communication between epithelial cells, which may result in decreased growth control within the infected epithelium and which is known to be an early event in carcinogenesis. Intriguingly, recent reports have brought up a role for the protein in the late stages of viral replication in differentiating epithelial cells as well as in apoptosis. In this report, we focus on the human ...