PDZ domain-containing proteins, such as PSD-95 and GRIP are thought to play key roles in glutamate receptor plasticity. GRIP-associated proteins (GRASPs) that bind to distinct PDZ domains within GRIP also play key roles in regulation of glutamate receptor function. GRASP-1 is a neuronal rasGEF associated with GRIP and AMPA receptors in vivo (Scannevin and Huganir, 2000). Recent work suggests that GRASP-1 may regulate neuronal ras signaling and contribute to the regulation of AMPA receptor distribution by NMDA receptor activity (Ye et al., 2000).
