ATG7
Description
The ATG7 (autophagy related 7) is a protein-coding gene located on chromosome 3.
Autophagy related 7 is a protein in humans encoded by ATG7 gene. Related to GSA7; APG7L; APG7-LIKE. ATG 7, present in both plant and animal genomes, acts as an essential protein for cell degradation and its recycling. The sequence associates with the ubiquitin- proteasome system, UPS, required for the unique development of an autophagosomal membrane and fusion within cells. ATG7 was identified based on homology to yeast cells Pichia pastoris GSA7 and Saccharomyces cerevisiae APG7. The protein appears to be required for fusion of peroxisomal and vacuolar membranes. Autophagy is an important cellular process that helps in maintaining homeostasis. It goes through destroying and recycling the cytoplasmic organelles and macromolecules. During the initiation of autophagy, ATG7 acts like an E-1 enzyme for ubiquitin-like proteins (UBL) such as ATG12 and ATG8. ATG7 helps these UBL proteins in targeting their molecule by binding to them and activating their transfer to an E-2 enzyme. ATG7's role in both of these autophagy-specific UBL systems makes it an essential regulator of autophagosome assembly.
ATG7 is an E1-like activating enzyme involved in two ubiquitin-like systems crucial for cytoplasm to vacuole transport (Cvt) and autophagy. It activates ATG12 for conjugation with ATG5, and the ATG8 family proteins for conjugation with phosphatidylethanolamine. These systems are essential for ATG8 association with Cvt vesicles and autophagosome membranes. ATG7 is required for autophagic death induced by caspase-8 inhibition. It facilitates LC3-I lipidation with phosphatidylethanolamine to form LC3-II, which is found on autophagosomal membranes. ATG7 is also necessary for mitophagy, which regulates mitochondrial quantity and quality by eliminating mitochondria to maintain cellular energy requirements and prevent excess ROS production. It modulates p53/TP53 activity to regulate the cell cycle and survival during metabolic stress. Additionally, ATG7 plays a vital role in maintaining axonal homeostasis, preventing axonal degeneration, maintaining hematopoietic stem cells, forming Paneth cell granules, and adipose differentiation. It regulates the liver clock and glucose metabolism by mediating the autophagic degradation of CRY1 (clock repressor) in a time-dependent manner. {ECO:0000250|UniProtKB:Q9D906, ECO:0000269|PubMed:11096062, ECO:0000269|PubMed:16303767, ECO:0000269|PubMed:22170151, ECO:0000269|PubMed:34161705}
ATG7 is also known as APG7-LIKE, APG7L, GSA7, SCAR31.
