Organisms Commons^™

Direct Cell-To-Cell Transmission Of Respiratory Viruses: The Fast Lanes, Nicolás P. Cifuentes-Muñoz, Rebecca Ellis Dutch, Roberto Cattaneo

Molecular and Cellular Biochemistry Faculty Publications

Virus particles protect genomes from hostile environments within and outside the host, eventually delivering these genomes to target tissues to initiate infection. Complex processes requiring significant energy and time are necessary to assemble these virus particles, but only a small portion of released virus will successfully infect new target cells (Fig 1A). While the science of virology has developed based on the isolation and purification of viral particles, it is becoming increasingly clear that direct cell-to-cell transmission of viruses and/or viral components is also highly relevant [1,2].

Direct cell-to-cell spread of infections has several advantages. The first is efficiency: genomic …

In Vivo Structures Of The Helicobacter Pylori Cag Type Iv Secretion System, Yi-Wei Chang, Carrie L. Shaffer, Lee A. Rettberg, Debnath Ghosal, Grant J. Jensen

Veterinary Science Faculty Publications

The type IV secretion system (T4SS) is a versatile nanomachine that translocates diverse effector molecules between microbes and into eukaryotic cells. Here, using electron cryotomography, we reveal the molecular architecture of the Helicobacter pylori cag T4SS. Although most components are unique to H. pylori, the cag T4SS exhibits remarkable architectural similarity to other T4SSs. Our images revealed that, when H. pylori encounters host cells, the bacterium elaborates membranous tubes perforated by lateral ports. Sub-tomogram averaging of the cag T4SS machinery revealed periplasmic densities associated with the outer membrane, a central stalk, and peripheral wing-like densities. Additionally, we resolved pilus-like …