ATG

ATG may refer to:

Autophagy-related protein 101

Autophagy-related protein 101 also known as ATG101 is a protein that in humans is encoded by the C12orf44 gene (chromosome 12 open reading frame 44).

Autophagy is the process of forming a vacuole around proteins and nucleic acids that are to be broken down in lysosomes. The transcribed mRNA sequence of C12orf44 is 1287 base pairs, and following translation the sequence is 218 amino acids in length. The ATG101 protein is localized in the cytoplasm, but can possibly also be found bound to a structure known as a phagophore, involved in autophagy. The gene is highly conserved among mammals, as well as showing conservation among most eukaryotes. It is thought to directly interact with ATG13 in the ULK1 complex, which may be important for activating phagophores.

Function

ATG101 is a newly found important autophagy related protein, among many other proteins responsible for autophagy, a process well conserved among most eukaryotic organisms. However, ATG101 is not homologous to any of the other ATG proteins. ATG101 interacts with essential autophagy protein ATG13 in mammals, which is a ULK1 interacting protein. ULK1 (unc-51-like kinase 1) is thought to be important to the activation of macroautophagy in mammals. ATG101 is suggested to protect ATG13 from proteasomal degradation, therefore stabilizing levels of ATG13 found in cells and regulating levels of macroautophagy. According to published papers, ATG101 is said to localize to the isolation membrane, also known as a phagophore. This attachment to the phagophore could possibly explain the palmitoylation site found on the third AA, which is a cysteine. Phagophores are responsible for recognizing and surrounding materials that are to be degraded in the lysosome, by forming a membrane that completely surrounds the materials to be degraded.

ATG12

Autophagy-related protein 12 is a protein that in humans is encoded by the ATG12 gene.

Autophagy is a process of bulk protein degradation in which cytoplasmic components, including organelles, are enclosed in double-membrane structures called autophagosomes and delivered to lysosomes or vacuoles for degradation. ATG12 is the human homolog of a yeast protein involved in autophagy (Mizushima et al., 1998).[supplied by OMIM]

Autophagy requires the covalent attachment of the protein Atg12 to ATG5 through a ubiquitin-like conjugation system. The Atg12-Atg5 conjugate then promotes the conjugation of ATG8 to the lipid phosphatidylethanolamine.

Atg12 was found to be involved in apoptosis. This protein promotes apoptosis through an interaction with anti-apoptotic members of the Bcl-2 family.

References

Further reading