This website uses cookies so that we can provide you with the best user experience possible. Cookie information is stored in your browser and performs functions such as recognising you when you return to our website and helping our team to understand which sections of the website you find most interesting and useful.
ATG2A engages Rab1a and ARFGAP1 positive membranes during autophagosome biogenesis
Output Details
Description
Autophagosomes form from seed membranes that expand through bulk-lipid transport via the bridge-like lipid transporter ATG2. The origins of the seed membranes and their relationship to the lipid transport machinery are poorly understood. Using proximity labeling and a variety of fluorescence microscopy techniques, we show that ATG2A localizes to extra-Golgi ARFGAP1 puncta during autophagosome biogenesis. ARFGAP1 itself is dispensable during macroautophagy, but among other proteins associating to these membranes, we find that Rab1 is essential. ATG2A co-immunoprecipitates strongly with Rab1a, and siRNA-mediated depletion of Rab1 blocks autophagy downstream of LC3B lipidation, similar to ATG2A depletion. Further, when either autophagosome formation or the early secretory pathway is perturbed, ARFGAP1 and Rab1a accumulate at ectopic locations with autophagic machinery. Our results suggest that ATG2A engages a Rab1a complex on select early secretory membranes at an early stage in autophagosome biogenesis.
Identifier (DOI)
10.1101/2025.03.24.645038