The amino-terminal region of Atg3 is essential for association with phosphatidylethanolamine in Atg8 lipidation.
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.
Hanada
Takao
T
Division of Molecular Cell Biology, National Institute for Basic Biology, Myodaiji, Okazaki 444-8585, Japan.
Satomi
Yoshinori
Y
Takao
Toshifumi
T
Ohsumi
Yoshinori
Y
D001343:Autophagy / Q000502:physiology*; D000071190:Autophagy-Related Protein 8 Family; D000071183:Autophagy-Related Proteins; D008247:Lysosomes / Q000235:genetics / Q000378:metabolism*; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D010714:Phosphatidylethanolamines / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary / Q000502:physiology; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D025801:Ubiquitin / Q000235:genetics / Q000378:metabolism; D044763:Ubiquitin-Conjugating Enzymes / Q000235:genetics / Q000378:metabolism*; D014617:Vacuoles / Q000235:genetics / Q000378:metabolism
C113757:ATG8 protein, S cerevisiae; D000071190:Autophagy-Related Protein 8 Family; D000071183:Autophagy-Related Proteins; D008869:Microtubule-Associated Proteins; D010714:Phosphatidylethanolamines; D029701:Saccharomyces cerevisiae Proteins; D025801:Ubiquitin; C483858:phosphatidylethanolamine; D044763:Ubiquitin-Conjugating Enzymes; C104235:ATG3 protein, S cerevisiae