title: Characterization of the diffusion of epidermal growth factor receptor clusters by single particle tracking.
abstract: A number of studies have shown that receptors of the epidermal growth factor receptor family (ErbBs) exist as higher-order oligomers (clusters) in cell membranes in addition to their monomeric and dimeric forms. Characterizing the lateral diffusion of such clusters may provide insights into their dynamics and help elucidate their functional relevance. To that end, we used single particle tracking to study the diffusion of clusters of the epidermal growth factor (EGF) receptor (EGFR; ErbB1) containing bound fluorescently-labeled ligand, EGF. EGFR clusters had a median diffusivity of 6.8×10(-11)cm(2)/s and were found to exhibit different modes of transport (immobile, simple, confined, and directed) similar to that previously reported for single EGFR molecules. Disruption of actin filaments increased the median diffusivity of EGFR clusters to 10.3×10(-11)cm(2)/s, while preserving the different modes of diffusion. Interestingly, disruption of microtubules rendered EGFR clusters nearly immobile. Our data suggests that microtubules may play an important role in the diffusion of EGFR clusters either directly or perhaps indirectly via other mechanisms. To our knowledge, this is the first report probing the effect of the cytoskeleton on the diffusion of EGFR clusters in the membranes of live cells.
authors.affiliation: Howard P. Isermann Department of Chemical and Biological Engineering & Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.
authors.forename: Mohan
authors.initials: M
authors.lastname: Boggara
authors.forename: Krishna
authors.initials: K
authors.lastname: Athmakuri
authors.forename: Sunit
authors.initials: S
authors.lastname: Srivastava
authors.forename: Richard
authors.initials: R
authors.lastname: Cole
authors.forename: Ravi S
authors.initials: RS
authors.lastname: Kane
mesh_terms: D000199:Actins / Q000737:chemistry; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism; D016000:Cluster Analysis; D003599:Cytoskeleton / Q000378:metabolism; D004058:Diffusion; D019281:Dimerization; D004815:Epidermal Growth Factor / Q000378:metabolism; D066246:ErbB Receptors / Q000737:chemistry*; D036681:Fluorescence Recovery After Photobleaching; D006801:Humans; D008024:Ligands; D008856:Microscopy, Fluorescence / Q000379:methods; D008870:Microtubules / Q000737:chemistry / Q000378:metabolism; D015233:Models, Statistical; D013997:Time Factors
chemical_list: D000199:Actins; D008024:Ligands; D004815:Epidermal Growth Factor; D066246:ErbB Receptors