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Updated: May 22, 2026
07:20
Imaging ATG9A, a Multi-Spanning Membrane Protein
Published on: June 16, 2023
Atg18 interaction positions Atg2 for efficient lipid transfer into phagophore elongation
Sabrina Chumpen Ramirez1,2, Dmitry Shvarev2,3, Prado Vargas Duarte4
1Osnabrück University, Department of Biology/Chemistry, Biochemistry Section, Osnabrück, Germany.
The EMBO Journal
|May 20, 2026
Summary
Researchers elucidated the structure of yeast Atg2 and its partner Atg18, revealing how this complex facilitates lipid transfer essential for autophagosome formation during macroautophagy.
Area of Science:
- Cell Biology
- Molecular Biology
- Structural Biology
Background:
- Macroautophagy requires lipid flux for autophagosome biogenesis.
- The mechanisms controlling membrane contact site (MCS) formation and lipid transfer directionality remain unclear.
Purpose of the Study:
- To determine the structure of the yeast Atg2-Atg18 complex.
- To elucidate the role of Atg2 in lipid transfer during autophagosome formation.
Main Methods:
- Cryo-electron microscopy (cryo-EM) to solve the structure of Atg2-Atg18.
- Molecular dynamics (MD) simulations to analyze complex function.
Main Results:
- A novel interface in Atg2, crucial for Atg18 recruitment and lipid transfer, was identified.
- Structural evidence showed Atg2's internal cavity is lipid-filled, even in the cytosol.
- MD simulations revealed the complex induces membrane curvature, facilitating lipid transfer.
Conclusions:
- The Atg2-Atg18 complex plays a critical role in directional lipid flux for phagophore expansion.
- Structural and dynamic insights provide a mechanistic understanding of lipid transfer in macroautophagy.
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