PRR7 (proline rich 7), also known as Synaptic proline-rich membrane protein, is a 269 amino acid protein expressed in postsynaptic density (PSD) of the forebrain, especially in hippocampus. The proline rich sequence for which the protein is named is characteristic of a region that is involved in protein-protein interactions, acting as a ligand for SH3, WW and EVH1 domains. As a single-pass type III membrane protein, evidence shows that PRR7 forms a postsynaptic membrane complex with PSD-95 and NMDAz1, suggesting its possible function in the modulation of neural activities. The expression pattern in brain also suggests that PRR7 is essential for synaptic formation or maturation, specifically in the cerebrum. Two isoforms of PRR7 exist as a result of an alternative splicing event.