Dual specificity phosphatase that dephosphorylates MAP kinase MAPK1/ERK2 on both 'Thr-183' and 'Tyr-185', regulating its activity during the meiotic cell cycle. 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 Expression in lung increases after birth. Up-regulated by growth factors and mitogens. Phosphorylation at Ser-359 and Ser-364 by MAPK1/ERK2 and MAPK3/ERK1 reduces its rate of degradation. Belongs to the protein-tyrosine phosphatase family. Non-receptor class dual specificity subfamily.