Thierry Arnould: Différentes facettes des interactions entre organites

Membrane-bound organelles such as mitochondria, peroxisomes, or the endoplasmic reticulum (ER),lysosomes create distinct environments to promote specific cellular tasks such as ATP production, lipid breakdown, molecule degradation and recycling or protein export. During recent years, it has become evident that organelles are integrated into cellular networks regulating metabolism, intracellular signaling, cellular maintenance, cell fate decision, and pathogen defence. In order to facilitate such signaling events, specialized membrane regions between apposing organelles bear distinct sets of proteins to enable tethering, physical and functional interactions. These interactions are usually mediated by apposing membrane contact sites or organelle-derived vesicles (ODV) as illustrated for mitochondria. Moreover, maintenance of cellular homeostasis requires the precise removal of aged organelles by autophagy—a process which involves the detection of ubiquitinated organelle proteins by the autophagosome membrane, representing another site of membrane associated-signaling. We will briefly discuss several facets of organelle interactions from literature and data generated in URBC.