FIGURE 3.
Ubiquitin-like conjugation systems that play roles in the early steps of autophagy. Early steps in autophagosome formation are regulated by two ubiquitin-like conjugation systems. In both cases, a ubiquitin-like protein (Atg8 and Atg12) is conjugated to an E1-like enzyme (Atg7), and then to an E2-like enzyme (Atg3 and Atg10). These are then used to form phosphatidylethanolamine (PE) conjugates of Atg8 (LC3 II) as well as protein conjugates of Atg5/12/16.