Protein kinase B (PKB/Akt)--a key regulator of glucose transport?

The serine/threonine kinase protein kinase B (PKB/Akt) has been shown to play a crucial role in the control of diverse and important cellular functions such as cell survival and glycogen metabolism. There is also convincing evidence that PKB plays a role in the insulin-mediated regulation of glucose transport. Furthermore, states of cellular insulin resistance have been shown to involve impaired PKB activation, and this usually coincides with a loss of glucose transport activation. However, evidence to the contrary is also available, and the role of PKB in the control of glucose transport remains controversial. Here we provide an overview of recent findings, discuss the potential importance of PKB in the regulation of glucose transport and metabolism, and comment on future directions.