Autophagy related 7 is a
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respon ...
in humans encoded by ''ATG7''
gene
In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...
.
Related to GSA7; APG7L; APG7-LIKE.
ATG 7, present in both plant and animal
genomes
In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding gen ...
, 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 protein
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 ...
s (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.
Homologous to the ATP-binding and catalytic sites of E1 activator proteins, ATG7 uses its cysteine residue to create a thiol-ester bond with free Ubiquitin molecules.
Through UPS, Ubiquitin will continue to bind to other autophagy-related proteins, E2 conjugation proteins and E3 protein ligases, to attach Ubiquitins to a target substrate to induce autophagy.
ATG 7 is often associated with
ATG12/
ATG5 sequenced ubiquitination cascade. As well in presence of
p53
p53, also known as Tumor protein P53, cellular tumor antigen p53 (UniProt name), or transformation-related protein 53 (TRP53) is a regulatory protein that is often mutated in human cancers. The p53 proteins (originally thought to be, and often s ...
cell cycle pathways during stressed and nutrient poor environments.
References
Further reading
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External links
* {{UCSC gene info, ATG7