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Updated: Nov 7, 2025

Author Spotlight: Imaging ATG9A, a Multi-Spanning Membrane Protein
Published on: June 16, 2023
Atg2 and Atg9: Intermembrane and interleaflet lipid transporters driving autophagy
1Institute of Microbial Chemistry (BIKAKEN), Tokyo, Japan.
Abstract:
Autophagy, an intracellular degradation mechanism, involves de novo generation of autophagosomes that sequester and deliver cytoplasmic components to the lysosome for degradation. The mechanism behind autophagosomal membrane expansion has been a longstanding enigma in this field. Recent structural and biochemical analyses have revealed that two mysterious autophagy-related (Atg) proteins, Atg2 and Atg9, are novel types of intermembrane and interleaflet lipid transporters, respectively. This review summarizes recent discoveries surrounding Atg2 and Atg9 as a lipid transporter and discusses the molecular mechanism of autophagosomal membrane expansion driven by collaboration between these two lipid transporters.
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