| Background |
AMP-activated protein kinases (AMPKs) constitute a serine/threonine protein kinase family, which is highly conserved from yeast to plants and animals and plays a key role in the regulation of energy homeostasis. AMPKα1, AMPKα2, MELK, and SNARK are the catalytic subunits in the family. Recently, AMPK-related protein kinase ARK5 was identified, which shares 84% similarity with the sequence of the catalytic domain of SNARK. in vitro, Akt phosphorylates ARK5 at Ser600. This phosphorylation activates ARK5, resulting in increased phosphorylation of the SAMS peptide, an AMPK consensus substrate. in vivo experiments showed that Akt-activated ARK5 is critical for the survival of cells under glucose starvation. Furthermore, studies also linked ARK5 to tumor invasion. Overexpressed ARK5 leads to a higher tumor growth rate. For example, the overexpression of ARK5 in pancreatic tumor cell line PANC-1 significantly elevates its metastasis in the liver.
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