Dual specificity phosphatase able to dephosphorylate phosphotyrosine, phosphoserine and phosphothreonine residues within the same substrate, with a preference for phosphotyrosine as a substrate (By similarity). Involved in the modulation of intracellular signaling cascades. May regulate glucose metabolism by activating, AMPK, an energy sensor protein kinase. Affects MAP kinase signaling though modulation of the ERK1/2 cascade in skeletal muscle promoting muscle cell differentiation, development and atrophy (By similarity). H2O + O-phospho-L-tyrosyl-[protein] = L-tyrosyl-[protein] + phosphate H2O + O-phospho-L-seryl-[protein] = L-seryl-[protein] + phosphate H2O + O-phospho-L-threonyl-[protein] = L-threonyl-[protein] + phosphate Homodimer (By similarity). Interacts with PRKAA2 (By similarity). Belongs to the protein-tyrosine phosphatase family. Non-receptor class dual specificity subfamily.