Protein phosphatase which regulates actin filament dynamics (PubMed:11832213, PubMed:16169194). Dephosphorylates and activates the actin binding/depolymerizing factor tsr/cofilin, which subsequently binds to actin filaments and stimulates their disassembly (PubMed:11832213). Required for axon growth (PubMed:15572110). 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 Interacts with actin. Strongly expressed in apical regions of the assembling ommatidia of the eye-imaginal disk. Apical expression requires the receptor tyrosine kinases Egfr and sev/sevenless. Tyrosine phosphatase activity has not been demonstrated for this protein to date. Belongs to the protein-tyrosine phosphatase family.