PSD-95 (postsynaptic density protein 95) is human protein encoded by the DLG4 gene. PSD-95 is the best studied member of the MAGUK-family of PDZ domain-containing proteins. It is almost exclusively located in the post synaptic density of neurons, and is involved in anchoring synaptic proteins. Its direct and indirect binding partners include neuroligin, NMDA receptors, AMPA receptors, and potassium channels. It plays an important role in synaptic plasticity and the stabilization of synaptic changes during long-term potentiation.