Differential Diffusional Properties in Loose and Tight Docking Prior to Membrane Fusion

Witkowska A, Spindler S, Mahmoodabadi RG, Sandoghdar V, Jahn R (2020)

Publication Type: Journal article

Publication year: 2020

Journal

Biophysical Journal Biophysical Society

DOI: 10.1016/j.bpj.2020.10.033

Abstract

Fusion of biological membranes, although mediated by divergent proteins, is believed to follow a common pathway. It proceeds through distinct steps, including docking, merger of proximal leaflets (stalk formation), and formation of a fusion pore. However, the structure of these intermediates is difficult to study because of their short lifetime. Previously, we observed a loosely and tightly docked state preceding leaflet merger using arresting point mutations in SNARE proteins, but the nature of these states remained elusive. Here, we used interferometric scattering (iSCAT) microscopy to monitor diffusion of single vesicles across the surface of giant unilamellar vesicles (GUVs). We observed that the diffusion coefficients of arrested vesicles decreased during progression through the intermediate states. Modeling allowed for predicting the number of tethering SNARE complexes upon loose docking and the size of the interacting membrane patches upon tight docking. These results shed new light on the nature of membrane-membrane interactions immediately before fusion.

Authors with CRIS profile

Susann Spindler Lehrstuhl für Experimentalphysik Vahid Sandoghdar Lehrstuhl für Experimentalphysik

Involved external institutions

Max-Planck-Institut für die Physik des Lichts (MPL) / Max Planck Institute for the Science of Light DE Germany (DE) Max-Planck-Institut für biophysikalische Chemie (Karl-Friedrich-Bonhoeffer-Institut) / Max Planck Institute for Biophysical Chemistry DE Germany (DE)

How to cite

APA:

Witkowska, A., Spindler, S., Mahmoodabadi, R.G., Sandoghdar, V., & Jahn, R. (2020). Differential Diffusional Properties in Loose and Tight Docking Prior to Membrane Fusion. Biophysical Journal. https://doi.org/10.1016/j.bpj.2020.10.033

MLA:

Witkowska, Agata, et al. "Differential Diffusional Properties in Loose and Tight Docking Prior to Membrane Fusion." Biophysical Journal (2020).

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