Other proteins implicated in synaptic autophagy include the heterotetramer adaptor protein complex 2/AP-2 complex, which functions in autophagosome retrograde transport to enhance autophagy, and BSN/Bassoon, which inhibits autophagy via an ATG5 interaction that limits ATG12–ATG5 complex formation; these proteins are mutated in the context of hereditary spastic paraplegia and PSP, respectively [460]. Here, ATG5 is linked to hereditary spastic paraplegia.