The conjugation of ATG8 (autophagy-related 8) proteins to the lipid phosphatidylethanolamine (PE) is the result of the coordinated and highly regulated action of several ATG core proteins, including ATG4 proteases and the E1 (ATG7)- and E2 (ATG3)- activating enzymes. Although it has been stablished that ROS signaling plays an important role in autophagy activation, the molecular mechanisms underlying the redox control of ATG proteins remain largely unclear. We have recently shown that ATG3 activity in Chlamydomonas reinhardtii is subjected to reversible redox regulation to ensure ATG8 lipidation and autophagy progression under ROS-linked stress conditions. Abbreviations: ATG, Autophagy-related; Cys, Cysteine; DTTred, Reduced Dithiothreitol; MM(PEG24), Methyl Polyethylene Glycol Maleimide; NEM: N-ethylmaleimide; PE, Phosphatidylethanolamine; ROS, Reactive Oxygen Species; TOR, Target Of Rapamycin; Trx, Thioredoxin; WT, Wild Type.