Positive regulator of dendritic spine morphogenesis and density. Required for the maintenance of excitatory synaptic transmission. Binds phosphatidylinositol 4,5-bisphosphate. Interacts (via C-terminus) with DLG1, DLG2, DLG3 and DLG4/PSD95. Interacts (via N-terminus) with ARHGEF7; the interaction is mediated by the PDZ domain. Interacts with GPSM2 (via TPR repeat region). Expressed in various regions of the brain, including cortex, hippocampus, cerebellum, olfactory bulb and medial habenular nucleus. The FERM domain mediates the interaction with phosphatidylinositol 4,5-bisphosphate. Wrong choice of CDS.