Figure 7
Cupidin/Homer scaffolds for actin cytoskeleton modulators and postsynaptic proteins. Cupidin/Homer2 acts as a scaffold tethering postsynaptic signalling proteins (such as mGluR1α/5, IP3R, and Shank) as well as the dendritic actin-binding protein Drebrin, a spine actin modulator, via the N-terminal EVH-1 domain, which recognizes the PPxxF consensus motif. It also links the GTP-bound, activated Cdc42 small GTPase, which is known to regulate filopodia formation, via the C-terminal CBD (Cdc42-binding domain) and forms a tetrameric scaffold complex via the C-terminal coiled-coil (CC) and Leu zipper motif (LZA and LZB) regions. The Homer scaffold complex is implicated in the facilitation of signalling crosstalk among tethered synapse proteins and regulation of the actin-based morphology of dendritic spines.