The Atg2 protein, an integral membrane protein, is required for a range of functions including the regulation of autophagy in conjunction with the Atg1-Atg13 complex. Atg2 binds Atg9. It is a lipid transfer protein required for autophagosome completion and peroxisome degradation. It is part of the RBG (repeating beta-grooves) superfamily together with VPS13, SHIP164, Csf1, and the Hob proteins, which all share the same structure consisting of long hydrophobic grooves made of multiple repeating modules of five beta-sheets followed by a loop [4,5].

1: Apg2 is a novel protein required for the cytoplasm to vacuole targeting, autophagy, and pexophagy pathways. Wang CW, Kim J, Huang WP, Abeliovich H, Stromhaug PE, Dunn WA Jr, Klionsky DJ; J Biol Chem. 2001;276:30442-30451. PMID:11382760

2: The Atg1-Atg13 complex regulates Atg9 and Atg23 retrieval transport from the pre-autophagosomal structure. Reggiori F, Tucker KA, Stromhaug PE, Klionsky DJ; Dev Cell. 2004;6:79-90. PMID:14723849

3: Autophagy: molecular machinery for self-eating. Yorimitsu T, Klionsky DJ; Cell Death Differ. 2005;12:1542-1552. PMID:16247502

4: A novel superfamily of bridge-like lipid transfer proteins. Neuman SD, Levine TP, Bashirullah A; Trends Cell Biol. 2022;32:962-974. PMID:35491307

5: Vps13-like proteins provide phosphatidylethanolamine for GPI anchor synthesis in the ER. Toulmay A, Whittle FB, Yang J, Bai X, Diarra J, Banerjee S, Levine TP, Golden A, Prinz WA; J Cell Biol. 2022; [Epub ahead of print] PMID:35015055