Enables chondroitin sulfate binding activity; heparin binding activity; and protein tyrosine phosphatase activity. Involved in several processes, including negative regulation of neuron projection development; peptidyl-tyrosine dephosphorylation; and regulation of postsynaptic density assembly. Acts upstream of or within central nervous system development and establishment of endothelial intestinal barrier. Located in Schaffer collateral - CA1 synapse; glutamatergic synapse; and plasma membrane. Is integral component of presynaptic membrane. Is expressed in several structures, including adipose tissue; genitourinary system; gut; nervous system; and sensory organ. Orthologous to human PTPRS (protein tyrosine phosphatase receptor type S). [provided by Alliance of Genome Resources, Apr 2022]