Akt: a new activation mechanism.

Protein Kinase B (PKB), more commonly referred to as Akt, is a serine/threonine-specific protein kinase. It is well established as a critical signaling node that regulates a myriad of cellular functions including proliferation, survival, apoptosis and metabolism, which are also processes important for tumorigenesis1. Indeed, the roles of Akt in cancer have been extensively scrutinized over the years and documented in many studies. However, more studies are still emerging to further increase our knowledge of this complex master regulator. In a recent paper published in Nature, Liu et al.2 have identified a new phosphorylation event on the Akt extreme carboxyl (C)-terminus, specifically on residues S477 and T479, which activates Akt and subsequent downstream oncogenic cellular functions.