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.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Autophagy / physiology*
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Autophagy-Related Protein 8 Family
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Autophagy-Related Proteins
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Lysosomes / genetics
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Lysosomes / metabolism*
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Microtubule-Associated Proteins / genetics
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Microtubule-Associated Proteins / metabolism*
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Phosphatidylethanolamines / genetics
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Phosphatidylethanolamines / metabolism*
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Protein Structure, Tertiary / physiology
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Saccharomyces cerevisiae / cytology
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Saccharomyces cerevisiae / genetics
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Saccharomyces cerevisiae / metabolism*
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Saccharomyces cerevisiae Proteins / genetics
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Saccharomyces cerevisiae Proteins / metabolism*
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Ubiquitin / genetics
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Ubiquitin / metabolism
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Ubiquitin-Conjugating Enzymes / genetics
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Ubiquitin-Conjugating Enzymes / metabolism*
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Vacuoles / genetics
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Vacuoles / metabolism
Substances
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ATG8 protein, S cerevisiae
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Autophagy-Related Protein 8 Family
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Autophagy-Related Proteins
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Microtubule-Associated Proteins
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Phosphatidylethanolamines
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Saccharomyces cerevisiae Proteins
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Ubiquitin
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phosphatidylethanolamine
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Ubiquitin-Conjugating Enzymes
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ATG3 protein, S cerevisiae