Exploring the ATG9A interactome uncovers interaction with VPS13A.

Area of Science:

• Cell Biology
• Molecular Biology
• Biochemistry

Background:

• ATG9A is a core autophagy protein involved in autophagosome expansion, potentially acting as a lipid scramblase.
• Its function is thought to involve interaction with ATG2A, a lipid transfer protein.
• ATG9A also plays roles in membrane repair and lipid droplet homeostasis.

Purpose of the Study:

• To identify novel ATG9A interactors within and beyond the autophagy pathway.
• To elucidate the functional significance of these interactions.

Main Methods:

• Interactome analysis using mass spectrometry.
• Co-immunoprecipitation assays to confirm direct interactions.

Main Results:

• Mass spectrometry identified proteins involved in lipid synthesis and trafficking, including ACSL3, VPS13A, and VPS13C.
• Direct interaction between ATG9A and VPS13A was confirmed.
• A distinct ATG9A-VPS13A complex was observed, separate from the ATG9A-ATG2A complex.

Conclusions:

• ATG9A interacts with key proteins in lipid metabolism, suggesting broader roles in cellular lipid homeostasis.
• The formation of a distinct ATG9A-VPS13A complex points to novel regulatory mechanisms in cellular processes.
• Further research is warranted to explore the functional implications of these newly identified interactions.