Autophagy-related protein 9A (ATG9A)

Autophagy-related protein 9A (ATG9A) is a unique and essential multispanning transmembrane protein in the core autophagy machinery, characterized by a homotrimeric domain-swapped structure and a network of branched internal cavities thought to mediate lipid or phospholipid transport across membranes. ATG9A is involved in early autophagosome formation and membrane expansion, potentially through its putative lipid scramblase activity, and is necessary for the proper function of lipid droplet homeostasis and mitochondrial fatty acid mobilization. It localizes to highly curved membrane domains, such as small vesicles at the phagophore assembly site, and interacts with other key autophagy proteins such as ATG2A through its cytosolic C-terminal domain. Loss of ATG9A impairs autophagy and disrupts lipid and energy metabolism, with implications for diseases involving defective autophagy or altered lipid regulation. Its critical, broadly essential cellular roles present significant challenges for therapeutic targeting

Other names

APG9L1FLJ22169APG9-like 1mATG9APG9 autophagy 9-like 1ATG9 autophagy related 9 homolog Aautophagy 9-like 1 proteinMGD3208

Membrane lipid scramblase activity (phospholipid translocation across bilayer); Scaffolding for recruitment of autophagy machinery; Regulation of autophagosome membrane dynamics and curvature