Stimulation of ATG12-ATG5 conjugation by ribonucleic acid Journal Article


Authors: Shao, Y.; Gao, Z.; Feldman, T.; Jiang, X.
Article Title: Stimulation of ATG12-ATG5 conjugation by ribonucleic acid
Abstract: The ubiquitin-like conjugation reactions, ATG8/microtubule-associated protein 1 light chain 3/MAP1LC3 (LC3) to phosphatidylethanolamine (PE) and ATG12 to ATG5, are biochemical hallmarks for autophagy, a cellular process that degrades bulk cellular proteins and organelles. The two conjugation reactions share the same E1-like enzyme ATG7 but have different E2-like enzymes, ATG3 for LC3-PE and ATG10 for ATG12-ATG5. In cells, ATG12-ATG5 conjugation appears to be required for LC3-PE conjugation. Previously, in vitro reconstitution of LC3-PE conjugation, but not the upstream ATG12-ATG5 conjugation, was reported. In this study, we describe for the first time the de novo reconstitution of mammalian ATG12-ATG5 conjugation by using purified recombinant proteins. We show that ATG7, ATG10 and ATP as an energy source are all essential for ATG12-ATG5 conjugation, and mutation of the specific lysine residue of ATG5 for ATG12 conjugation abrogates the reaction. Furthermore, a potent stimulating activity for ATG12-ATG5 conjugation was detected in mammalian cell extracts, and was surprisingly identified as ribosomes. Our detail biochemical analyses indicate that the ribonucleic acid (RNA) component of ribosomes is both necessary and sufficient for this stimulation. ©2007 Landes Bioscience.
Keywords: controlled study; unclassified drug; human cell; mutation; proteins; mammalia; animals; gene product; enzyme activity; hela cells; rna; ubiquitination; protein processing, post-translational; recombinant protein; spodoptera; adenosine triphosphate; phosphatidylethanolamine; phosphatidylethanolamines; rna, ribosomal; autophagy; ubiquitin-conjugating enzymes; protein derivative; lysine; cell extracts; ribosomes; conjugation; ribosome; cell extract; microtubule-associated proteins; enzyme reconstitution; atg12; atg5; ribonucleic acid (rna); microtubule associated protein 1; protein atg10; protein atg12; protein atg3; protein atg5; protein atg7
Journal Title: Autophagy
Volume: 3
Issue: 1
ISSN: 1554-8627
Publisher: Taylor & Francis Group  
Date Published: 2007-01-01
Start Page: 10
End Page: 16
Language: English
PUBMED: 16963840
PROVIDER: scopus
DOI/URL:
Notes: --- - "Cited By (since 1996): 11" - "Export Date: 17 November 2011" - "Source: Scopus"
Citation Impact
MSK Authors
  1. Xuejun Jiang
    114 Jiang
  2. Zhonghua Gao
    6 Gao
  3. Yufang Shao
    7 Shao