Virus Entry: Looking Back and Moving Forward

Abstract

Research over a period of more than half a century has provided a reasonably accurate picture of mechanisms involved in animal virus entry into their host cells. Successive steps in entry include binding to receptors, endocytosis, passage through one or more membranes, targeting to specific sites within the cell, and uncoating of the genome. For some viruses, the molecular interactions are known in great detail. However, as more viruses are analyzed, and as the focus shifts from tissue culture to in vivo experiments, it is evident that viruses display considerable redundancy and flexibility in receptor usage, endocytic mechanism, location of penetration, and uncoating mechanism. For many viruses, the picture is still elusive because the interactions that they engage in rely on sophisticated adaptation to complex cellular functions and defense mechanisms.

Keywords: Receptors; animal viruses; endocytosis; membrane fusion; signaling.

Graphical abstract

Legend

This article is part of the thematic collection Molecular Mechanisms of Early Virus–Host Cell Interactions edited by Pierre-Yves Lozach (U. Heidelberg). Artwork by Rachel Davidowitz, Freelance Scientific Illustrator.

Fig. 1

Anno 1980 perspective of receptor-mediated endocytosis. Note that at that time endosomes were not yet known to be part of endocytic pathways. Cartoon kindly provided by Pierre De Meyts originally published in The mechanism and role of hormone-induced clustering of membrane receptors, Trends in Biochemical Sciences, Vol 5 (8), p210–214, 1980 by J. Schlessinger.