High impact information on ATG12

• The carboxy-terminal glycine residue of Apg12, a 186-amino-acid protein, is conjugated to a lysine at residue 149 of Apg5, a 294-amino-acid protein [1].
• Apg7p exhibits a considerable similarity to ubiquitin-activating enzyme (E1) and is found to activate Apg12p with ATP hydrolysis [2].
• Apg16p is required for the function of the Apg12p-Apg5p conjugate in the yeast autophagy pathway [3].
• We recently found that a protein conjugation system, in which Apg12p is covalently attached to Apg5p, is indispensable for autophagy in yeast [3].
• The Apg12-Apg5 and Apg16 are localized in the cytosol and pre-autophagosomal structures and play an essential role in autophagosome formation [4].

Biological context of ATG12

• The Crystal Structure of Plant ATG12 and its Biological Implication in Autophagy [5].
• The dimerization of Apg7p is independent of the other Apg proteins and facilitated by overexpressed Apg12p [6].

Associations of ATG12 with chemical compounds

• Two conjugation reactions related to ubiquitination are essential for autophagy: Apg12p conjugation to Apg5p, and Apg8p conjugation to the lipid phosphatidylethanolamine [7].

Physical interactions of ATG12

• These results indicated that Apg12p interacts with Apg7p via a thioester bond [8].

Regulatory relationships of ATG12

• Cells expressing mutant Apg7ps, Apg7pG333A, or Apg7pC507A showed defects in autophagy and cytoplasm-to-vacuole targeting of aminopeptidase I. These results indicated that Apg7p functions as a novel protein-activating enzyme necessary for Apg12p-Apg5p conjugation [8].

Other interactions of ATG12

• We show that the Apg5-Apg12 conjugation system is conserved in Dictyostelium [7].
• Autophagic nutrient recycling in Arabidopsis directed by the ATG8 and ATG12 conjugation pathways [9].
• The attachment of Apg12p, a modifier with no significant similarity to ubiquitin, to Apg5p is crucial for autophagy in yeast [2].

References