Virion motility of sialoglycan-cleaving respiratory viruses

Here, we review how respiratory viruses function as molecular motors by exploiting their glycan receptor-binding and -destroying glycoproteins. The resulting virion motility drives their mucus penetration and exploration of cell surfaces for locations permitting induction of entry. We discuss the role of virus morphology, kinetic parameters of receptor engagement and receptor heterogeneity, summarize physical models for virion motility and identify key gaps in our understanding of these dynamic processes.