Towards the identification of proteins involved in autophagosome initiation within organelles contact sites in the plant cell

Details

Supervisors

Batoko, Henri ; Ghislain, Michel

Faculty

Faculté des bioingénieurs

Degree label

Master [120] : bioingénieur en chimie et bioindustries, à finalité spécialisée

Abstract

Macroautophagy, hereafter called autophagy, is a highly conserved and ubiquitous process in eukaryotic cells that eliminates cytosolic components in response to starvation and cellular stresses. Cytoplasmic components to be degraded are engulfed in a double-membrane vesicle called autophagosome, formed de novo. Autophagosome formation is a sequential and tightly regulated process initiated at organelle contact sites involving the endoplasmic reticulum (ER). The ER is a large, single-copy, membrane-bound organelle that includes an elaborate 3D network of diverse structural subdomains, including highly curved tubules, flat sheets, and parts that form contacts with nearly every other organelle. Organelle membrane contact sites (MCS) play crucial physiological roles in cell metabolism and signaling, and recent evidence suggest they are also autophagosome initiation sites. However, our knowledge of the molecular structure of contact sites and mechanisms underlying autophagosome initiation are rudimentary, and more so in the plant cell. We reason that using an MCS-specific bait protein involved in autophagosome initiation and a proximity-dependent biotinylation identification (BioID) methods could substantial contribute in our understanding of the molecular architecture of MCS during autophagosome initiation. Our results suggest that the designed and validated tool combined with proteomic BioID could shed light on the molecular organization of MCS and the molecular mechanisms of autophagosome initiation in the plant cell