Dual specificity phosphatase that dephosphorylates MAP kinase MAPK1/ERK2 on both 'Thr-188' and 'Tyr-190', regulating its activity during the meiotic cell cycle. H2O + O-phospho-L-seryl-[protein] = L-seryl-[protein] + phosphate H2O + O-phospho-L-threonyl-[protein] = L-threonyl-[protein] + phosphate H2O + O-phospho-L-tyrosyl-[protein] = L-tyrosyl-[protein] + phosphate Expressed in XIK-2 kidney cells. Present in both immature and mature oocytes (at protein level). Expressed at a constant level during oocyte growth as well as during oocyte maturation. Levels decline somewhat during cleavage (stages 3-6). Levels rise dramatically during the mid-blastula transition. This higher level of expression is then maintained through gastrulation and all subsequent developmental stages. By serum stimulation, heat shock and oxidative stress. Phosphorylated by MAPK1/ERK2 at Thr-168 and at one or more serine residues in a progesterone-dependent manner. Phosphorylation reduces its rate of degradation but does not seem to affect phosphatase activity. Belongs to the protein-tyrosine phosphatase family. Non-receptor class dual specificity subfamily.