Electron Tomography and Simulation of Baculovirus Actin Comet Tails Support a Tethered Filament Model of Pathogen Propulsion

• DOI: 10.1371/journal.pbio.1001765
• Publication Date: 2014-01-14T21:07:14Z
• Authors: Jan Mueller; Julia Pfanzelter; Christoph Winkler; Akihiro Narita; Christophe Le Cla...; Maria Nemethova; Marie-France Carlier; Yuichiro Maeda; Matthew D. Welch; Taro Ohkawa; Christian Schmeiser; Guenter P. Resch; J. Victor Small
• Keywords: Actin remodeling

Several pathogens induce propulsive actin comet tails in cells they invade to disseminate their infection. They achieve this by recruiting factors for nucleation, the Arp2/3 complex, and polymerization regulators from host cytoplasm. Owing limited information on structural organization of comets particular spatial arrangement filaments engaged propulsion, underlying mechanism pathogen movement is currently speculative controversial. Using electron tomography we have resolved three-dimensional architecture propelling baculovirus, smallest yet known hijack motile machinery. Comet tail geometry was also mimicked mixtures virus capsids with purified a minimal inventory regulators. We demonstrate that propulsion based assembly fishbone-like array organized subsets linked branch junctions, an average four pushing at any one time. energy-minimizing function simulated structure as well tracks adopted baculovirus infected vivo. The results simulations rule out gel squeezing models support those which are continuously tethered during nucleation polymerization. Since Listeria monocytogenes, Shigella flexneri, Vaccinia among other use same common toolbox components move, suggest share principles mode propulsion.