Can bidirectionally induce pre- and post-synaptic differentiation of neurons by mediating interaction with IL1RAP and IL1RAPL1 trans-synaptically. Involved in pre-synaptic differentiation through interaction with SLITRK2. H2O + O-phospho-L-tyrosyl-[protein] = L-tyrosyl-[protein] + phosphate Interacts with PPFIA1, PPFIA2 and PPFIA3 (PubMed:9624153). Interacts (via extracellular domain) with SLITRK4 (via LRR 1 and 2 repeats). Interacts with SLITRK2; induces presynaptic differentiation. Interacts (via the second immunoglobilin domain) with IL1RAPL1 (via the first immunoglobilin domain); induces pre- and postsynaptic differentiation of neurons and synapse formation. Interacts (via the third immunoglobilin domain) with IL1RAP (via the first immunoglobilin domain); induces pre- and postsynaptic differentiation of neurons (By similarity). Additional isoforms seem to exist. A cleavage occurs, separating the extracellular domain from the transmembrane segment. This process called 'ectodomain shedding' is thought to be involved in receptor desensitization, signal transduction and/or membrane localization. May be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay. Belongs to the protein-tyrosine phosphatase family. Receptor class 2A subfamily.