Tetraspanins as facilitators of viral and cellular information transfer

Abstract

Cells that are infected by a virus can infect other cells by passing on the viral genome. Such transfer of viral genetic information can occur by fusion of infected and uninfected cells, or through extracellular particles that are shed from infected cells and which carry the viral genome together with viral structural proteins and/or enzymes to uninfected target cells. The transfer of viral information, either by cell-cell fusion or via viral particles, requires the coordination of numerous membrane-based functions, several of which are regulated by tetraspanins. In many ways, viral particles resemble cell-derived vesicles such as, for example, exosomes, which are known to transport (structural, biochemical, and genetic) information through extracellular space. With this brief essay, in addition to reviewing what we currently know about various tetraspanin functions during the replication of enveloped viruses, I will also discuss some of the similarities between viral and cellular information transfer processes. Emphasis will be placed on how, in either case, tetraspanins can facilitate short- and long-range transmission as well as transfer via cell-cell fusions.