CYFIP/Sra-1 Controls Neuronal Connectivity in Drosophila and Links the Rac1 GTPase Pathway to the Fragile X Protein

Neuronal plasticity requires actin cytoskeleton remodeling and local protein translation in response to extracellular signals. Rho GTPase pathways control actin reorganization, while the fragile X mental retardation protein (FMRP) regulates the synthesis of specific proteins. Mutations affecting either pathway produce neuronal connectivity defects in model organisms and mental retardation in humans. We show that CYFIP, the fly ortholog of …