ATG3 Human

ATG3 acts as an E2 ubiquitin-like conjugating enzyme in the ATG8 conjugation system, which is indispensable for the elongation of the phagophore, a precursor to the autophagosome . The autophagosome is a double-membrane structure that sequesters cytoplasmic components, cellular organelles, invading microorganisms, and aggregated proteins, which are then degraded upon fusion with lysosomes .

ATG3 is responsible for the E2-like covalent binding of phosphatidylethanolamine (PE) to the C-terminal glycine of ATG8-like proteins (such as GABARAP and MAP1LC3A). This step is crucial for the membrane association of ATG8-like proteins, which is essential for autophagy and the cytoplasm-to-vacuole transport (Cvt) pathway . Additionally, ATG3 interacts with ATG7 (an E1-like enzyme) to facilitate the conjugation of ATG12 to ATG5, promoting the transfer of ATG8-like proteins from ATG3 to PE .

Recent studies have also highlighted autophagy-independent functions of ATG3, including its role in DNA damage-induced mitosis and cell differentiation . These functions suggest that ATG3 has broader implications beyond its traditional role in autophagy.

Recombinant human ATG3 is a purified form of the protein used in various research applications to study its functions and mechanisms. It is typically produced in a controlled laboratory environment to ensure high purity and activity . The recombinant protein is used to investigate the biochemical properties of ATG3, its interactions with other proteins, and its role in autophagy and other cellular processes.

Mutations or dysregulation of ATG3 have been associated with several diseases, including granulomatous amebic encephalitis and neurodegeneration with brain iron accumulation . Understanding the functions and mechanisms of ATG3 can provide insights into the pathophysiology of these diseases and potentially lead to the development of therapeutic strategies.