PRKAA1 and cancer: Under metabolic stress caused by glucose and amino acid deficiency, elevated AMP binds to the CBS-3 domain of the gamma subunit, directly phosphorylates Thr172 residues of the α subunit(α-172), and binds AMPK to axons on lysosomal membranes, activating AMPK through phosphorylation of α-172 by LKB1 (Liver kinase B1, a cancer suppressor gene encoded by STK11 gene and composed of STRAD, STE20, and MO25) in lysosomes.