DLG3 (discs large homologue 3), also called synapse-associated protein 102 (SAP102), is a scaffolding protein that clusters at synapses and plays an important role in synaptic development and plasticity []. It associates with GluN2 subunits of NMDA receptors, particularly GluN2B which is the dominant subunit in cortical neurons during early development []. Mutations in DLG3 are associated with nonsyndromic X-linked mental retardation in humans [, ]. DLG3 is a member of the MAGUK (membrane-associated guanylate kinase) protein family, which is characterized by the presence of a core of three domains: PDZ, SH3, and guanylate kinase (GuK). The GuK domain in MAGUK proteins is enzymatically inactive; instead, the domain mediates protein-protein interactions and associates intramolecularly with the SH3 domain. DLG3 contains three PDZ domains [].This entry represents the SH3 domain of DLG3.
