Could be involved in tyrosine phosphatase signalling pathways, having MAP-kinases as substrates. 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 Non-dividing gametes did not express the VH-PTP13 gene whereas synchronously dividing vegetative cells only expressed VH-PTP13 in the early G1-phase of the cycle. By oxidative stress. Belongs to the protein-tyrosine phosphatase family. Non-receptor class dual specificity subfamily.