The protein encoded by this gene belongs to the ser/thr protein kinase family.It is the catalytic subunit of the 5’-prime-AMP-activated protein kinase (AMPK).AMPK is a cellular energy sensor conserved in all eukaryotic cells.The kinase activity of AMPK is activated by the stimuli that increase the cellular AMP/ATP ratio.AMPK regulates the activities of a number of key metabolic enzymes through phosphorylation.It protects cells from stresses that cause ATP depletion by switching off ATP-consuming biosynthetic pathways.Alternatively spliced transcript variants encoding distinct isoforms have been observed.