Seminar by Weria Pezeshkian

Membrane Remodelling: from molecular structure to large scale deformation

Weria Pezeshkian 

(Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials, University of Groningen, Groningen, Netherlands)

One of the essential features of biological membranes is their ability to be dynamically remodelled in a living cell. Biological membrane shape is continuously adapted to accommodate important cellular processes or by interactions with invasive pathogenic complexes, e.g., cell division, endocytosis. There has been a great attempt to understand these processes using macroscopic phenomenological equations that involve only a few elastic parameters. These approaches are indeed successful in describing the shape of simple bilayers, but are very limited for complex membranes as the precise molecular machinery becomes essential.

Computer simulation methods are robust techniques to elucidate complex membrane behaviours. However, distinct simulation technique is optimized for a specific length scale and therefore has a limited capacity for describing membrane remodelling since they typically involve a wide range of length and time scales. To resolve this limitation, we have developed a multi-scale simulation scheme, specifically optimised for membrane remodelling processes, by combining all-atom molecular dynamics, coarse-grained particle-based model and continuum membrane model. We have successfully applied the procedure to several biological processes e.g., membrane tubular invaginations induced by peripheral membrane proteins, and obtained predictions for experimental testing. Notable findings of the results include a generic molecular design of toxic proteins for local membrane curvature generation, protein clustering through harnessing membrane shape fluctuations and membrane softening at high protein concentrations.