Viruses and the fuel sensor: the emerging link between AMPK and virus replication.

Adenosine 5' monophosphate-activated protein kinase (AMPK) is conserved in all eukaryotic cells and functions as the key regulator of cellular metabolism by responding to the energy status of the cell. It is activated by an increase in the AMP : ATP ratio and then attempts to redress the balance by upregulating catabolic processes, whilst concomitantly inhibiting anabolic processes. Despite its critical importance in the functioning of eukaryotic cells, there has been a paucity of studies investigating the potential for dysregulation of AMPK by viruses. Recently, however, there have been a number of reports that have begun to address this gap in our knowledge. In this article, we will review this emerging field, outlining how a variety of viruses have been shown to either stimulate or inhibit AMPK activity. We will also document the effects of these perturbations on the biology of virus infection, in particular with regard to the ability of viruses to persist or cause cytopathogenesis.