Lipid transfer protein required for autophagosomes completion and peroxisome degradation (PubMed:16303567, PubMed:30911189). Tethers the edge of the isolation membrane (IM) to the endoplasmic reticulum (ER) and mediates direct lipid transfer from ER to IM for IM expansion (PubMed:30911189). Atg2 binds to the ER exit site (ERES), which is the membrane source for autophagosome formation, using basic residues in its N-terminal region (NR) and to the expanding edge of the IM through its C-terminal region (PubMed:30911189). The latter binding is assisted by an atg18-PtdIns3P interaction (PubMed:30911189). Atg2 then extracts phospholipids from the membrane source using its NR and transfers them to atg9 to the IM through its predicted beta-sheet-rich structure for membrane expansion (PubMed:30911189). Atg2 is also involved in the recruitment of lipids to a restricted region close to the vacuole, termed the vacuole-isolation membrane contact site (VICS), which is also essential for autophagosome formation (By similarity). May have a role in sporulation (PubMed:16303567). a 1,2-diacyl-sn-glycero-3-phosphocholine(in) = a 1,2-diacyl-sn-glycero-3-phosphocholine(out) a 1,2-diacyl-sn-glycero-3-phospho-L-serine(in) = a 1,2-diacyl-sn-glycero-3-phospho-L-serine(out) a 1,2-diacyl-sn-glycero-3-phosphoethanolamine(in) = a 1,2-diacyl-sn-glycero-3-phosphoethanolamine(out) Localizes to the IM-ERES contact site. The N-terminal region (NR) associates with the endoplasmic reticulum (ER) and is responsible for the formation of the isolation membrane at the PAS. The amphipathic helix in the C-terminal region binds to membranes and facilitates atg18 binding to PtdIns3P to target the atg2-atg18 complex to the PAS. Impairs atg8-processing. Belongs to the ATG2 family.