Báo cáo khoa học: Atg8L/Apg8L is the fourth mammalian modifier of mammalian Atg8 conjugation mediated by human Atg4B, Atg7 and Atg3

Atg8L/Apg8L is the fourth mammalian modifier of mammalian Atg8 conjugation mediated by human Atg4B, Atg7 and Atg3

Authors: Isei Tanida, Yu-shin Sou, Naoko Minematsu-Ikeguchi, Takashi Ueno and Eiki Kominami

Field: Molecular Cell Biology, Department of Biochemistry, Juntendo University School of Medicine, Tokyo, Japan

Document Content: This research investigates Atg8L/Apg8L, identified as the fourth mammalian homolog of Atg8. The study examines whether its modification process is mediated by human Atg4B, Atg7, and Atg3, similar to other known mammalian Atg8 homologs like LC3, GABARAP, and GATE-16. Experiments involving HEK293 cells demonstrated that the C-terminus of Atg8L undergoes cleavage. In vitro analyses confirmed that human Atg4B, but not Atg4A or Atg4C, cleaves the C-terminus of Atg8L. Furthermore, Atg8L-I forms an E1-substrate intermediate with Atg7C572S and an E2-substrate intermediate with Atg3C264S. The modified form of Atg8L, designated Atg8L-II, was observed to accumulate in HeLa cells when treated with lysosomal protease inhibitors under nutrient-rich conditions. These findings collectively indicate that Atg8L functions as the fourth modifier in the mammalian Atg8 conjugation system.

Detailed Table of Contents:

• Keywords
• Correspondence
• Abstract
• Introduction
• Results
• Discussion
• Experimental procedures
• Materials, and biochemical and molecular biological techniques
• Cell culture
• Antibodies
• Immunoblotting analyses
• In vitro assay for cleavage of the C-terminus of TRX-Atg8L-3xFLAG by Atg4B
• Fluorescence microscopy
• Acknowledgements
• References