The amino-terminal region of Atg3 is essential for association with phosphatidylethanolamine in Atg8 lipidation

Abstract 

Autophagy is a bulk degradation process conserved among eukaryotes. In macro-autophagy, autophagosomes sequester cytoplasmic components and deliver their contents to lysosomes/vacuoles. Autophagosome formation requires the conjugation of Atg8, a ubiquitin-like protein, to phosphatidylethanolamine (PE). Here we report that the amino (N)-terminal region of Atg3, an E2-like enzyme for Atg8, plays a crucial role in Atg8–PE conjugation. The conjugating activities of Atg3 mutants lacking the 7 N-terminal amino acid residues or containing a Leu-to-Asp mutation at position 6 were severely impaired both in vivo and in vitro. In addition, the amino-terminal region is critical for interaction with the substrate, PE.

Structured summary

MINT-7010457: ATG8 (uniprotkb:P38182) and ATG3 (uniprotkb:P40344) bind (MI:0407) by biochemical (MI:0401)

Abbreviations: PE, phosphatidylethanolamine, LEP, lysyl endopeptidase, ALP, alkaline phosphatase, PS, phosphatidylserine, SCF, Skp1-Cullin-F-box protein

Keywords: Autophagy, Autophagosome, Ubiquitin-like protein, Phosphatidylethanolamine, Atg3, Atg8–PE