Sequesters mitogen-activated protein kinases (MAPKs) such as MAPK1, MAPK3 and MAPK14 in the cytoplasm in an inactive form. The MAPKs bind to a dephosphorylated kinase interacting motif, phosphorylation of which by the protein kinase A complex releases the MAPKs for activation and translocation into the nucleus (By similarity). H2O + O-phospho-L-tyrosyl-[protein] = L-tyrosyl-[protein] + phosphate Interacts with MAPKs. Widely expressed in the brain, most abundant in cerebellum, midbrain, cerebral cortex and hippocampus. Also expressed in heart and skeletal muscle. By nerve growth factor; isoform 2 is induced in adrenal tumor cells 2 hours after exposure, levels are down-regulated 24 hours after treatment. Belongs to the protein-tyrosine phosphatase family. Receptor class 7 subfamily.