Autophagy is the natural, conserved degradation of the cell that removes unnecessary or dysfunctional components through a lysosome-dependent regulated mechanism. It allows the orderly degradation and recycling of cellular components. Although initially characterized as a primordial degradation pathway induced to protect against starvation, it has become increasingly clear that autophagy also plays a major role in the homeostasis of non-starved cells. Defects in autophagy have been linked to various human diseases, including neurodegeneration and cancer, and interest in modulating autophagy as a potential treatment for these diseases has grown rapidly.
Beclin-1 is a protein that in humans is encoded by the BECN1 gene. Beclin-1 is a mammalian ortholog of the yeast autophagy-related gene 6 (Atg6) and BEC-1 in the C. elegans nematode. This protein interacts with either BCL-2 or PI3k class III, playing a critical role in the regulation of both autophagy and cell death.
Autophagy related 5 (ATG5) is a protein that, in humans, is encoded by the ATG5 gene located on Chromosome 6. It is an E3 ubi autophagic cell death. ATG5 is a key protein involved in the extension of the phagophoric membrane in autophagic vesicles. It is activated by ATG7 and forms a complex with ATG12 and ATG16L1. This complex is necessary for LC3-I conjugation to PE (phosphatidylethanolamine) to form LC3-II. ATG5 can also act as a pro-apoptotic molecule targeted to the mitochondria. Under low levels of DNA damage, ATG5 can translocate to the nucleus and interact with survivin.
Microtubule-associated proteins 1A/1B light chain 3B is a protein that in humans is encoded by the MAP1LC3B gene. LC3 is a central protein in the autophagy pathway where it functions in autophagy substrate selection and autophagosome biogenesis. LC3 is the most widely used marker of autophagosomes.
Microtubule-associated proteins 1A/1B light chain 3A is a protein that in humans is encoded by the MAP1LC3A gene. Two transcript variants encoding different isoforms have been found for this gene.
NEDD8-activating enzyme E1 catalytic subunit is a protein that in humans is encoded by the UBA3 gene.
Cysteine protease ATG4B is an enzyme that in humans is encoded by the ATG4B gene.
Autophagy-related protein 10 is a protein that in humans is encoded by the ATG10 gene.
Autophagy related 16 like 1 is a protein that in humans is encoded by the ATG16L1 gene. This protein is characterized as a subunit of the autophagy-related ATG12-ATG5/ATG16 complex and is essentially important for the LC3 (ATG8) lipidation and autophagosome formation. This complex localizes to the membrane and is released just before or after autophagosome completion.
WD repeat domain phosphoinositide-interacting protein 2 is a protein that in humans is encoded by the WIPI2 gene.
AKT-interacting protein is a protein that in humans is encoded by the AKTIP gene.
NEDD8-conjugating enzyme Ubc12 is a protein that in humans is encoded by the UBE2M gene.
Autophagy-related protein 9A is a protein that in humans is encoded by the ATG9A gene.
Autophagy related 7 is a protein in humans encoded by ATG7 gene. Related to GSA7; APG7L; APG7-LIKE.
Ubiquitin-fold modifier 1, also known as UFM1, is a protein which in humans is encoded by the UFM1 gene.
Cysteine protease ATG4A is an enzyme that in humans is encoded by the ATG4A gene.
Autophagy-related protein 8 (Atg8) is a ubiquitin-like protein required for the formation of autophagosomal membranes. The transient conjugation of Atg8 to the autophagosomal membrane through a ubiquitin-like conjugation system is essential for autophagy in eukaryotes. Even though there are homologues in animals, this article mainly focuses on its role in lower eukaryotes such as Saccharomyces cerevisiae.
Autophagy-related protein 13 also known as ATG13 is a protein that in humans is encoded by the KIAA0652 gene.
In molecular biology, autophagy related 3 (Atg3) is the E2 enzyme for the LC3 lipidation process. It is essential for autophagy. The super protein complex, the Atg16L complex, consists of multiple Atg12-Atg5 conjugates. Atg16L has an E3-like role in the LC3 lipidation reaction. The activated intermediate, LC3-Atg3 (E2), is recruited to the site where the lipidation takes place.
Ubiquitin-like proteins (UBLs) are a family of small proteins involved in post-translational modification of other proteins in a cell, usually with a regulatory function. The UBL protein family derives its name from the first member of the class to be discovered, ubiquitin (Ub), best known for its role in regulating protein degradation through covalent modification of other proteins. Following the discovery of ubiquitin, many additional evolutionarily related members of the group were described, involving parallel regulatory processes and similar chemistry. UBLs are involved in a widely varying array of cellular functions including autophagy, protein trafficking, inflammation and immune responses, transcription, DNA repair, RNA splicing, and cellular differentiation.
