In thisstudy, we identified that activated autophagy degrades the eukaryotic initiation factor4G1 (eIF4G1) and postsynaptic density protein-95 (PSD-95) in hippocampal neurons ofFmr1 KO mice and FXS neurons from patients, which subsequentlycorrected the dysregulated postsynaptic organization and actin assembly, the criticalprocesses determining synaptic maturation and density. The gene discussed is DLG4; the disease is fragile X syndrome.