Abstract
Chaperone-mediated autophagy (CMA), once considered a secondary or auxiliary degradation pathway, is now recognized as a central regulator of synaptic proteostasis. A recent study by Khawaja et al. (2025) in Nature Cell Biology provides compelling evidence that CMA actively remodels the synaptic proteome in a sex-specific manner. Using a conditional knockout strategy based on Lamp2a-floxed mice crossed with a Camk2a-Cre driver line to achieve excitatory neuron-specific deletion of Lamp2a in adult mice, the authors revealed sexually divergent synaptic phenotypes: females exhibit enhanced presynaptic neurotransmitter release and GRIN/NMDAR-mediated plasticity, while males show increased postsynaptic GRIA/AMPAR activity due to impaired receptor endocytosis. These changes are driven by sex-specific degradation of synaptic proteins such as SYN1 (synapsin I) in females and AP2A/α-Adaptin in males. Importantly, reactivation of CMA - either genetically or pharmacologically - rescues synaptic dysfunction, seizure susceptibility, and memory deficits in aged mice and Alzheimer disease models. This commentary contextualizes these findings within the broader framework of activity-dependent proteostasis, sex-specific autophagy modulation, and therapeutic potential of CMA in brain aging and neurodegeneration.