Postsynaptic density membrane protein that indirectly regulates glutamatergic synaptic transmission through lysophosphatidic acid (LPA)-mediated signaling pathways. Binds lysophosphatidic acid (LPA) and mediates its internalization into cells. Could act as receptor or a transporter of this lipid at the post-synaptic membrane (By similarity). Modulates lysophosphatidic acid (LPA) activity in neuron axonal outgrowth during development by attenuating phospholipid-induced axon collapse (By similarity). Expressed by glutamatergic neurons (at protein level). O-glycosylated. Probably at Ser-346. Belongs to the PA-phosphatase related phosphoesterase family. Originally described as a 2-lysophosphatidate/LPA phosphatase (PubMed:12730698). However, following studies suggested it does not have such activity or only a residual one (PubMed:15280885). This is further supported by the fact that the phosphatase sequence motifs as well as the His residue acting as a nucleophile in active phosphatases of the PA-phosphatase related phosphoesterase family are not conserved (PubMed:15280885).