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 (PubMed:12730698). Specifically expressed in neurons (at protein level). Expressed in the subventricular zone and specifically in the hippocampal anlage at embryonic day 19 (E19). From postnatal stages on, expressed in the hippocampus and in the entorhinal cortex. In the dentate gyrus weakly expressed in the infrapyramidal blade at P0 and at P5 expressed in the suprapyramidal blade. This expression remains unchanged during maturation. A reduced expression is seen in adult brain. O-glycosylated. Probably at Ser-347. 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).