Akt/PKB, a serine/threonine kinase member of the AGC family of proteins, is 
involved in the regulation of a plethora of cellular processes triggered by a 
wide diversity of extracellular signals and is thus considered a key signalling 
molecule in higher eukaryotes. Deregulation of Akt signalling is associated with 
a variety of human diseases, revealing Akt-dependent pathways as an attractive 
target for therapeutic intervention. Since its discovery in the early 1990s, a 
large body of work has focused on Akt phosphorylation of two residues, Thr308 
and Ser473, and modification of these two sites has been established as being 
equivalent to Akt activation. More recently, Akt has been identified as a 
substrate for many different post-translational modifications, including not 
only phosphorylation of other residues, but also acetylation, glycosylation, 
oxidation, ubiquitination and SUMOylation. These modifications could provide 
additional regulatory steps for fine-tuning Akt function, Akt trafficking within 
the cell and/or for determining the substrate specificity of this signalling 
molecule. In the present review, we provide an overview of these different 
post-translational modifications identified for Akt, focusing on their 
consequences for this kinase activity.