Major phosphatase responsible with PTP3 for tyrosine dephosphorylation of MAP kinase HOG1 to inactivate its activity. May also be involved in the regulation of MAP kinase FUS3. May be implicated in the ubiquitin-mediated protein degradation. H2O + O-phospho-L-tyrosyl-[protein] = L-tyrosyl-[protein] + phosphate Interacts with HOG1. Present with 149 molecules/cell in log phase SD medium. Belongs to the protein-tyrosine phosphatase family. Non-receptor class subfamily.