Yeast serves as a well-established model organism to understand the molecular mechanisms of autophagy, a highly conserved cellular quality control mechanism. To selectively degrade diverse cargo such as organelles and aggregates, specific receptors recognize the cargo and recruit the scaffold protein Atg11. This marks the initiation step of autophagy. The Atg11 scaffold then recruits downstream machinery proteins, such as Atg9 vesicles and the Atg1 kinase. Recent findings show that to fulfil its role, Atg11 undergoes phase separation to form dynamic initiation hubs on cargo surfaces. These hubs subsequently mature into sites that drive phagophore nucleation. In this study we investigate the molecular and physical properties of initiation hubs and how cargo, receptors and components of the autophagy machinery influence hub formation.
Aims: Investigate initiation hub formation and how different stimuli influence hub formation in Yeast.
Methods: In vivo (e.g. Fluorescence microscopy, Western blotting) and in vitro (protein isolation, in vitro reconstitution) methods for investigating protein behaviours.
Results: Atg11 phase separation and thus initiation hub formation is influenced by the molecular and physical properties of different cargo, autophagy receptors and other autophagy proteins.
Conclusions: To adapt to various stimuli and cargo, the targeted degradation of cargo via autophagy hinges on the fine regulation of the properties of involved proteins and emerging condensates.