Wayne State University

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Physics & Astronomy

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March 8, 2018 | 3:30 p.m. - 5:00 p.m.
Category: Seminar
Location: Physics & Astronomy Department - Liberal Arts and Sciences #245 | Map
666 W. Hancock
Detroit, MI 48201
Cost: Free
Audience: Academic Staff, Alumni, Community, Current Graduate Students, Current Undergraduate Students, Faculty

Abstract: The organization and distribution of proteins in the plasma membrane is widely known to influence membrane protein functionality. However, it remains challenging to decipher the underlying mechanisms that regulate membrane protein properties in the complex environment of cellular membranes. To overcome these challenges, an experimental strategy is discussed, in which the distribution, oligomerization state, and mobility of membrane proteins can be explored in a planar polymer-tethered lipid bilayer of well-defined lipid compositions using single molecule-sensitive confocal detection strategies. Results from such model membrane experiments are presented, which explore the influence of native ligands, bilayer asymmetry, and cholesterol content on the sequestration/oligomerization of urokinase plasminogen activator receptors (uPAR) and integrins [1-4]. Moreover, dual-color confocal experiments are described, which provide information about the formation and composition of uPAR-integrin complexes and the role of membrane cholesterol therein. Polymer-tethered lipid bilayer systems, comprised of phospholipids and lipopolymers, are also characterized by remarkable materials properties, which make them suitable as cell surface-mimicking substrates for the analysis of adhesion and spreading of plated cells. To illustrate the feasibility of such an application, we discuss the assembly of cadherin chimera into clusters on the surface of a polymer-tethered lipid bilayer substrate to form stable cell-substrate cadherin linkages underneath migrating C2C12 myoblasts [5]. Cluster tracking experiments reveal the cytoskeleton-regulated long-range mobility of cell-substrate linkages, thereby displaying remarkable parallels to the dynamics of cadherin-based cell-cell junctions.

[1] A. P. Siegel et al. (2011) Biophys. J. 101, 1642.
[2] N. F. Hussain et al. (2013) Biophys. J. 104, 2212.
[3] Y. Ge et al. (2014) Biophys. J. 107, 2101.
[4] Y. Ge et al. (2018) Biophys. J. 114, 158.
[5] Y. Ge et al. (2016) Soft Matter 12, 8259.

For more information about this event, please contact W.J. Llope at 3135779805 or wjllope@wayne.edu.