Localization on the herpes simplex virus type 1 genome of a region encoding proteins involved in adsorption to the...

We have previously shown that aminoglycosides such as neomycin and the polyamino acids polylysine and polyarginine selectively inhibit the binding of herpes simplex virus type 1 (HSV-1) to the cellular receptor, whereas HSV-2 infection is unaffected. In the present study we took advantage of this difference between HSV-1 and HSV-2 by using HSV(-1)-HSV(-2) intertypic recombinants to locate a region on the HSV-1 genome encoding proteins affecting the binding of the virion to the cellular receptor. The results were consistent with those obtained by marker rescue experiments. The identified region, which mapped between coordinates 0.580 and 0.687, contains two partial and eight complete genes, including the glycoprotein C (gC) gene and two others with potential transmembrane sequences. Various gC monoclonal antibody-resistant mutants of HSV-1 as well as a mutant completely lacking gC were found to be fully sensitive to neomycin, suggesting that gC is not the site of drug sensitivity and is not essential for adsorption of virus to the cellular receptor. However, the rate of adsorption was reduced in the absence of gC, indicating a facilitating function of the glycoprotein. The universal nature of this HSV-1 receptor binding was revealed by the similarity in drug sensitivity of infectivity in four different cell lines from various tissues and species.