FIGURE 1: Comparison between ubiquitylation and Atg8ylation. (A) Principal components and steps of ubiquitylation. Note that misfolded or aggregated or otherwise engaged proteins are the principal targets for ubiquitylation. (B) Principal components and steps of Atg8ylation. Note that stressed membranes or membranes destined for a specific kind of remodeling are the principal targets for Atg8ylation. (C) The well-established lipidation cycle of mAtg8s (mammalian Atg8s: LC3A,B,C, GABARAP, GABRAPL1 and GABARAPL2) on target membranes. Green circles, polar groups of PE or PS.