Atg29 phosphorylation regulates coordination of the Atg17-Atg31-Atg29 complex with the Atg11 scaffold during autophagy initiation

In eukaryotes, the Atg1 kinase complex controls both autophagy induction and the recruitment of other autophagy proteins to the phagophore assembly site (PAS); however, it remains unclear how the Atg1 kinase complex itself is targeted to the PAS or regulated. In this study, we showed that the Atg17-Atg31-Atg29 complex displayed an elongated S-shaped structure, and the interaction of this complex with Atg11 was essential for recruiting the intact Atg1 kinase complex. The phosphorylation of Atg29 is the "switch" controlling the interaction, as it is required for both binding to Atg11 and the PAS targeting of the Atg17-Atg31-Atg29 complex.