Dual specificity phosphatase; can dephosphorylate both phosphotyrosine and phosphoserine or phosphothreonine residues. May suppress bsk/JNK activation during the immune response. 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 Inhibited by the tyrosine phosphatase inhibitor sodium vanadate. Interacts (via tyrosine-protein phosphatase domain) with bsk/JNK; the interaction dephosphorylates bsk. Mainly found in the nucleus. Belongs to the protein-tyrosine phosphatase family. Non-receptor class dual specificity subfamily. Wrong choice of frame.