non-receptor serine/threonine kinase AMPK AMPK is a highly evolutionarily conserved serine/threonine kinase, and orthologs of the AMPK subunits are found in all eukaryotic species. At the molecular level, AMPK is a heterotrimer complex comprising a catalytic alpha subunit, with a conventional serine/threonine protein kinase domain, and two regulatory subunits, beta and gamma. In mammals, each subunit is encoded by multiple genes (alpha1, alpha2, beta1, beta2, gamma1, gamma2, gamma3), which results in 12 possible combinations of AMPK complex. IMR:0002775 molecule_role