Lipid droplet biogenesis is a liquid phase separation spatially regulated by seipin and membrane curvature.
Valeria Zoni, Pablo Campomanes, Rasha Khaddaj, Abdou Rachid Thiam, Roger Schneiter and Stefano Vanni
Received Date: 9th August 19
Cells store energy in the form of neutral lipids packaged into micrometer-sized organelles named lipid droplets (LDs). These structures emerge from the endoplasmic reticulum (ER), but their biogenesis remains poorly understood. Using molecular simulations, we found that LD formation proceeds via a liquid-liquid phase separation process that is modulated by the physical properties and lipid composition of the ER membrane. LD formation is promoted at ER sites characterized by high membrane curvature and by the presence of the ER-associated protein seipin, that cause accumulation of triglycerides by slowing down their diffusion in the membrane. Our data indicate how a combination of membrane physical properties and protein scaffolding is used by the cell to regulate a broad and energetically-efficient biophysical process such as liquid/liquid phase separation to achieve LD biogenesis.
Read in full at bioRxiv.
This is an abstract of a preprint hosted on an independent third party site. It has not been peer reviewed but is currently under consideration at Nature Communications.