PRR7/TRAP3 (proline-rich 7, transmembrane adaptor protein 3) is a 28 kDa transmembrane adaptor protein ubiquitously expressed at low level (most in brain) . Its amino acid sequence is extremely conserved among mammalian and other species. PRR7/TRAP3 contains potential palmitoylation motif and is found in lipid rafts. It is a part of the complex postsynaptic density fraction in neurons and associates with PSD-95, NMDA receptor and probably other proteins. The intracellular domain of PRR7/TRAP3 contains several tyrosines, a proline-rich sequence, and a C-terminal PDZ-binding motif. So far nothing is known about function of this protein. It may be involved in regulation of some receptor signaling and in formation of neurologic and immunologic synapse.