On Thursday (05.06) we will host Dr. Francesca Giordano from the Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, Gif-sur-Yvette, France. Her lecture will be entitled: "Ménage à Trois: Structure and Function of the Mitochondria-ER-Lipid Droplet Junction”. The lecture will take place at 3 p.m. in the CN lecture hall and it will be followed by a get together.

Abstract:

Mitochondria, essential for energy conversion, and lipid droplets (LDs), crucial for energy storage, play key roles in maintaining cellular bioenergetics. To function properly and preserve membrane integrity, these organelles rely on a tightly regulated lipid exchange with the Endoplasmic Reticulum (ER), primary site of lipid synthesis. However, unlike other organelles, mitochondria and LDs are excluded from conventional vesicular trafficking pathways. Instead, lipid transfer between these compartments occurs at specialized membrane contact sites (CS), yet the precise mechanisms governing lipid shuttling, particularly how lipids are directed to LDs during their formation, remain largely unknown.

We have recently shown that ER Membrane subdomains Associated with Mitochondria (MAMs) are hotspots for LD formation, uncovering the existence of a three-way contact site connection between mitochondria, ER and LDs. We are currently investigating the morphology and the functional relevance of these three-way contacts for lipid transfer and storage in the cell using a combination of biochemical and imaging approaches including 3D Focused Ion Beam-Scanning Electron Microscopy (FIB-SEM). I will discuss our latest data showing that MAM act as key metabolic platforms regulating the crosstalk and lipid exchanges between ER, mitochondria and LDs.