Organelle contact sites: a new layer in the organization of Eukaryotic cells
Dr Benoît KORNMANN
University of Oxford, Department of Biochemistry, Oxford, United Kingdom
Wednesday, September 4th 2019 - 11 a.m.
- Auditorium, IGBMC
Hosted by Functional genomics and cancer, Fabien ALPY
Intracellular organelles constitute dense and branched membrane networks that are under constant remodeling. My lab is interested in how these organelle networks are generated, distributed and regulated. We also investigate how this networked morphology is related to the organelle's activity.
These highly extensive and dynamic networks cohabit in the extremely crowded cytoplasmic space. This situation leads to unwanted collisions and entanglements that needs to be resolved. We show that, in the case of mitochondria, these collisions and entanglements can be resolved by mitochondrial fission. Mechanical forces applied to mitochondrial tubules lead to the recruitment and activation of the mitochondrial fission machinery, leading to the resolution of entanglements. These results imply that a biochemical response can be triggered by a mechanical stimulus and that forces within the cells participate in the shaping of organelles.
The extended morphology of several organelles might allow them to contact each other to exchange lipid molecules. Because most of the factors involved in lipid exchange are unclear or unknown, we developed a novel method that uses transposons and next-generation sequencing to interrogate the yeast genome and map in a single step all proteins and protein domains necessary for growth in a given condition. We use it to identify redundancies in lipid exchange routes, but the power of the method finds myriad of applications far beyond our usage.