Modeling & simulations of autophagosome membranes. The defined lipid profile and composition (left) provides the molecular identity for the phagophore membranes and autophagosomes. A) MD simulation snapshot of the ER membrane with embedded membrane proteins shows bilayer fluctuations (left). Lipid composition controls several interdependent mechanical properties and thereby affects the emergent functions of the membrane (right). Parts of this figure have been modified and adapted from Ben-Dov & Korenstein, 2013; Cebecauer et al., 2018; Maeda et al., 2020. B) Sphingomyelin lipids enriched in autophagosomes can mediate specific lipid-lipid interactions with PC and sterols resulting in formation of ordered laterally segregated nanodomains (left). Further, SMs could form inter- & intramolecular H-bonds stabilizing the nascent clusters (right). C) Structure of ATG9A trimers shows central & lateral pores for lipid scrambling (left). In silico assay for scramblase activity of membrane proteins employs chemical