Myc's secret life without Max

Abstract

The Myc transcription factors are amongst the most potent human oncoproteins, and they fulfill essential functions during normal development. Myc heterodimerizes with a protein called Max, and it has been widely assumed that all of Myc's activities depend on this association with Max. Recent evidence calls this view into question, as Myc proteins have been shown to retain considerable biological activity when not bound to Max. The molecular nature of this Max-independent Myc activity is likely to be manifold; one aspect we have recently found not to require Max is Myc's ability to activate RNA polymerase III-dependent transcription. The discovery of these Max-independent functions changes our understanding of basic Myc biology and it may affect pharmaceutical approaches to inhibiting Myc activity. © 2009 Landes Bioscience.