Molecular mechanisms of condensate-membrane interaction and mutual reshaping

• Applicants: Dr. Jaime Agudo-Canalejo; Professor Dr. Roland L. Knorr
• Subject Area: Cell Biology ; Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 506366351

Membrane-bound organelles have been considered the fundamental organizational components of cells for decades. However, recent research has revealed that condensed biomolecular phases (herein ‘condensates’) play an additional intricate role in cellular organization with profound functional implications. Lacking a bounding membrane, condensates are dynamic structures that respond rapidly to changes in the cellular milieu. Although often referred to as ‘membrane-less organelles,’ evidence has emerged that condensates associate with membranes through interactions that are thus far only poorly understood. Our work has shown that wetting of membranes by condensates gives rise to novel membrane remodelling mechanisms in cells and determines evolutionarily-conserved physiological functions. Wetting events mediate the development of membrane-bound organelles in diverse processes ranging from autophagy in mammals to protein storage in plants [Nature, 2021, 2020; PNAS 2021; JCB 2021]. Using SPP2191 funding, we will interrogate the molecular principles of an entirely new class of condensate-mediated processes and their implications for cellular processes.This SPP2191 project will build upon our evidence-backed theoretical foundation to provide a detailed quantitative description of how condensates interact with membranes. Leveraging our substantial set of published and preliminary work, we will focus on three research areas. First, we will develop and validate an accurate condensate wetting screen, which combines a technically advantageous flat support and automated image analyses. This approach will allow us to build a quantitative wetting database in a high-throughput manner. Second, we will thoroughly and systematically examine specific condensates and their wetting conditions by precisely manipulating condensate and membrane biochemistries to generate a multidimensional ‘wetosome’ database comprehensively cataloguing conditions that induce wetting. In generating this database, we will collaborate closely with SPP2191 groups to analyse the broad array of condensates studied in this programme. Our study will employ a powerful combination of controlled reconstitution experiments and continuum curvature-elasticity theory to physiologically relevant condensate-membrane interactions, demonstrating the generalizability of condensate-membrane wetting phenomena. Third, we will unlock the predictive power of the wetosome database using data analyses to unravel the mechanisms of condensate-membrane interactions, thereby comprehensively defining the molecular grammar governing wetting.

• DFG Programme: Priority Programmes
• Subproject of: SPP 2191: Molecular Mechanisms of Functional Phase Separation
• International Connection: United Kingdom