How LC3/GABARAPs regulate autophagy. LC3/GABARAP proteins are initially synthesized as soluble precursors and become conjugated to PE in the isolation membrane during a series of reactions requiring the activity of several enzymes, including ATG3, ATG5, and ATG7. Several steps of autophagosome formation and their fusion with lysosomes have been proposed to require the action of LC3/GABARAPs. These steps are the promotion of isolation membrane elongation, isolation membrane closure, and the fusion of autophagosomes with lysosomes to form autolysosomes. LC3/GABARAPs have also been shown to link cargo material to the isolation membrane to confer selectivity to autophagy. This interaction is mediated by cargo receptors. The steps that were found to require LC3/GABARAPS in the work of Nguyen et al. (2016) are highlighted in red.