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). {ECO:0000250|UniProtKB:Q7TMB7, ECO:0000250|UniProtKB:Q7TME0}. This is the function of PLPPR4 (phospholipid phosphatase related 4, Ensembl gene identifier ENSG00000117600).