Disks large-associated protein 1, also known as GKAP or DAP-1, is a member of the SAPAP family. It is a synaptic protein that may play several roles in the molecular organisation of synapses and neuronal cell signalling [, ]. It has been linked to obsessive-compulsive disorder (OCD) [].SAPAP family members are PSD-95/SAP90-associated proteins localised at postsynaptic density []. Postsynaptic density (PSD) is a specialised submembranous structure within which synaptic membrane proteins are linked to cytoskeletonand signalling proteins. PSD-95/SAP90 is one of the major components of PSD, and functions as a scaffold protein for various ion channels and associated signalling molecules.