The mechanisms underlying the molecular assemblage of molecules at the synapse are not well understood. Recently, a number of novel anchoring/scaffold proteins that are associated with postsynaptic density (PSD) proteins have been isolated. SHANK1, SHANK2 and SHANK3 constitute a family of proteins that may function as molecular scaffolds in the PSD. SHANK is made of five domain/regions that are probably involved in protein-protein interactions: ankyrin repeats, an SH3 domain, a PDZ domain, a SAM domain, and a proline rich region. SHANK interacts directly with GKAP or SAPAP via its PDZ domain, thus potentially bridging the N-methyl-D-aspartate receptor (NMDA)-PSD-95-GKAP complex.