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Author Spotlight: Imaging ATG9A, a Multi-Spanning Membrane Protein
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ATG2A-WDR45/WIPI4-ATG9A complex-mediated lipid transfer and equilibration during autophagosome formation
Yang Wang1, Goran Stjepanovic1
1Kobilka Institute of Innovative Drug Discovery, School of Medicine, The Chinese University of Hong Kong, Shenzhen, Guangdong, China.
Autophagy
|March 21, 2025
Summary
This study reveals the structures of key autophagy complexes, ATG2A-WDR45/WIPI4 and ATG2A-WDR45/WIPI4-ATG9A, explaining how they transfer lipids from the ER to build autophagosomes for cellular homeostasis.
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- Macroautophagy/autophagy is a fundamental cellular process essential for maintaining homeostasis.
- Dysregulation of autophagy is implicated in various diseases.
- Autophagosome formation, crucial for autophagy, requires significant lipid supply, primarily from the endoplasmic reticulum (ER).
Purpose of the Study:
- To elucidate the structural basis of lipid transfer during autophagy.
- To understand the mechanism of autophagosome biogenesis.
- To provide insights into the function of the ATG2A-WDR45/WIPI4-ATG9A complex.
Main Methods:
- Cryo-electron microscopy (cryo-EM) to resolve complex structures.
- Molecular dynamics simulations to investigate lipid transfer mechanisms.
- Biochemical analysis of protein-lipid interactions.
Main Results:
- Determined the cryo-EM structures of ATG2A-WDR45/WIPI4 and ATG2A-WDR45/WIPI4-ATG9A complexes.
- Elucidated the role of ATG2A in mediating lipid extraction from membranes.
- Provided mechanistic insights into lipid transfer and re-equilibration for phagophore expansion.
Conclusions:
- The study provides critical structural and mechanistic understanding of lipid transfer machinery in autophagy.
- These findings are vital for comprehending autophagosome biogenesis and its role in cellular health.
- The research offers a foundation for exploring therapeutic strategies targeting autophagy-related diseases.
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