How viral oncogenes make the cell cycle.

Abstract

Oncogenic viruses provide their host cells with additional growth stimuli, thereby extending their proliferative capacity. This implies that viral oncogenes can override growth-suppressive signals, which control cell-cycle progression in untransformed cells. Viral oncoproteins deregulate cell-cycle control by interfering with receptor-mediated signal transduction pathways and the function of nuclear cell-cycle regulatory proteins. As a consequence of these regulatory interactions, many viral oncogenes induce the expression of cellular genes required for cell-cycle progression, including genes encoding G1 cyclins. Apparently, different oncogenic viruses target different subsets of these cell-cycle regulatory pathways to transform cells.