Atg23 stops incorrect merging of Atg9 transport vesicles when delivering materials to autophagosome formation sites

In Saccharomyces cerevisiae, the protein Atg23 is associated with Atg9 vesicles, preventing their premature fusion.

• Atg9 vesicles are crucial for supplying membrane lipids needed for autophagosome formation.
• Atg23 interacts with Atg9 vesicles after their formation, protecting them from unwanted fusion with other cellular membranes.
• The phosphorylation of Atg9 by the kinase Atg1 occurs when the vesicles reach the autophagosome formation site.
• This phosphorylation leads to the release of Atg23, allowing the recruitment of Atg2, which plays a role in lipid transfer for membrane expansion.
• The findings suggest that Atg1-dependent phosphorylation regulates the movement and behavior of Atg9 vesicles during the process of autophagosome biogenesis.

Simplified