Post Synaptic Density 95 kDa (PSD-95), also known as synapse associated protein 90 kDa (SAP90), is one of a family of membrane-associated proteins found in the postsynaptic density in forebrain neurons and certain presynaptic structures in the cerebellum. Like other members of the family, PSD-95 has three 90 amino acid repeats called PDZ domains followed by an SH3 domain and a yeast guanylate kinase homology (GuK) domain. PSD-95 is believed to participate in the clustering of certain proteins, including NMDA receptors, Shaker-type potassium channels at the synaptic membrane in central nervous system (CNS) neurons. There are two principal modes of interaction between PSD-95 and other proteins. NMDA receptors and shaker-type potassium channels both share C-terminal sequence homology consisting of a threonine/serine-X-valine-COOH (T/SXV) motif. Other neuronal proteins that share this motif (beta 1 adrenergic receptor, some serotonin receptors, some sodium channel subunits, and additional potassium channel subunits), and some of these proteins may interact with PSD-95 by binding to its PDZ domains. Neuronal nitric oxide synthase (nNOS), which lacks the T/SXV motif but which has its own PDZ domain, has been shown to associate with PSD-95 in vitro through a pseudo-homotypic PDZ-PDZ interaction.
Protein Aliases: discs large homolog 4; Disks large homolog 4; FLJ97752; FLJ98574; post synaptic density; post-synaptic density protein 95; Postsynaptic density protein 95; PSD-95; PSD-95 alpha 2b; PSD-95 beta; SAP-90; Synapse-associated protein 90; synapse-associated protein SAP90; Tax interaction protein 15
Gene Aliases: DLG4; Dlgh4; PSD-95; PSD95; SAP-90; SAP90; SAP90A