Role of Epg5 in selective neurodegeneration and Vici syndrome.

Autophagy activity is essential for the survival of neural cells. Impairment of autophagy has been implicated in the pathogenesis of neurodegenerative disorders. Unlike the massive neuron loss in mice deficient for autophagy genes essential for autophagosome formation, we demonstrated that mice deficient for the metazoan-specific autophagy gene Epg5 develop selective neuronal damage and exhibit key characteristics of amyotrophic lateral sclerosis. Epg5 deficiency blocks the maturation of autophagosomes into degradative autolysosomes, slows endocytic degradation and also impairs endocytic recycling. Recessive mutations in human EPG5 have recently been causally associated with the multisystem disorder Vici syndrome. Here we show that while Epg5 knockout mice display some features of Vici syndrome, many phenotypes are absent.