Resolving mechanisms of protein dynamics and organization at the cell membrane in single molecule detail

by Eilon Sherman

at Physics Colloquium

Tue, 27 Mar 2018, 15:30
Nanotechnology institute building (#51) room 15

Abstract

Signaling complexes are out of equilibrium heterogeneous multi molecular structures and sites for intracellular signal transduction Although they play a crucial role in cellular activation current research techniques have been unable to resolve their structure and formation mechanisms in intact cells I will briefly review recent advancements in far field super resolution optical microscopy and present a multi color Single Molecule Localization Microscopy SMLM approach for imaging multiple types of single molecules in fixed and live cells with resolution down to 20nm I will further describe a statistical framework to determine the nanoscale organization and cooperativity of molecular interactions in signaling complexes Using these techniques we observed that signaling complexes that determine immune T cell activation showed surprising patterns of dynamic nanoscale organization and a hierarchical network of cooperative interactions between the constituent molecules In the second part of my talk I will describe our study of protein mobility at the plasma membrane using single particle tracking SPT I will further present a methodological approach to resolve mixed subdiffusion mechanisms acting simultaneously on polydispersed samples and complex media such as cell membranes Using these tools we find that protein mobility of a short trans membrane protein is highly heterogeneous subdiffusive and ergodic like Individual trajectories can be broken into distinct mobility states having distinct underlying subdiffusion mechanisms These mechanisms include viscoelasticity fractality and confinement Taken together our results extend our understanding of protein dynamics organization and function within the complex medium of the cell Refreshments are served at 15:15

Created on 22-03-2018 by Bar Lev, Yevgeny (ybarlev)
Updaded on 22-03-2018 by Bar Lev, Yevgeny (ybarlev)