p19ARF/CDKN2A: Proteins and Enzymes

p19ARF (mouse) and p14ARF (human) has become an important player in cell cycle regulation. In mice, tumor suppressor effects appear to be mediated by interactions between p19ARF and the p53 tumor suppressor protein. p19ARF counters uncontrolled proliferation and oncogenic signals in p53 dependent pathways. Proteins encoded by the INK4a/ARF locus also play a role in Abelson virus transformation. Both p16INK4a and p19ARF are expressed in many cells as they emerge from the apoptotic crisis that characterizes the transformation process. p19ARF is an important part in cellular defense against transforming signals from the Abl oncoprotein, providing direct evidence that the p19ARF-p53 regulatory loop plays an important role in lymphoma induction.