Effect of tunicamycin on herpes simplex virus glycoproteins and infectious virus production

Abstract

The antibiotic tunicamycin, which blocks the synthesis of glycoproteins, inhibited the production of infectious herpes simplex virus. In the presence of this drug, ['4C]glucosamine and [3H]mannose incorporation was reduced in infected cells, whereas total protein synthesis was not affected. Gel electrophoresis of [2-3H]mannose-labeled polypeptides failed to detect glycoprotein D or any of the other herpes simplex virus glycoproteins. By use of specific antisera we demonstrated that in the presence of tunicamycin the normal precursors to viral glycoproteins failed to appear. Instead, lower-molecular-weight polypeptides were found which were antigenically and structurally related to the glycosylated proteins. Evidence is presented to show that blocking the addition of carbohydrate to glycoprotein precursors with tunicamycin results in the disappearance of molecules, possibly due to degradation of the unglycosylated polypeptides. We infer that the added carbohydrate either stabilizes the envelope proteins or provides the proper structure for correct processing of the molecules needed for infectivity. The contribution of the carbohydrate portion of viral glycoproteins to infectivity, antigenicity,

Effect of tunicamycin and monensin on biosynthesis, transport, and maturation of bovine herpesvirus type-1 glycoproteins

“…This may explain the lower density of the noninfectious virus particles produced by tunicamycin-treated cells. The influence of tunicamycin on infectivity indicated that glycosylation of the viral proteins is required for the production of infectious virus, a phenomenon previously reported for several other enveloped viruses (Schwartz et aL, 19'76, Morrison et aL, 19'78;Nakamura and Compans, 19'78;Stohrer and Hunter, 1979;Pizer et al, 1980). When GBK cells were treated with monensin, reduced amounts of infectious virus particles were produced.…”

“…Tunicamycin, by acting as an analog of UDP-N-acetylglucosamine, interferes with the formation of the N-acetylglucosamine pyrophosphoryldolichol intermediate and thereby completely inhibits the synthesis of N-linked oligosaccharide side chains (Schwartz and Datema, 1980). Consequently, all glycoprotein-containing enveloped viruses are affected by tunicamycin in such a way that it prevents maturation and production of infectious virus (Schwartz et ai, 1976, Morrison et al, 1978Nakamura and Compans, 1978;Stohrer and Huner, 1979;Pizer et aL, 1980). Monensin is a carboxylic ionophore that is able to equilibrate Na+/K+ levels with a selectivity for Na+ (Pressman, 1976).…”

Inhibitors of protein glycosylation and glycoprotein processing in viral systems

“…There are several reports that inhibitors N-glycosylation block production of infectious HSV. Thus, tunicamycin reduces the yield of infectious virus by a factor of 103 and 2deoxyglucose by a factor of about 102 (Pizer et al, 1980;K~tz et al, 1980K~tz et al, Courtney et al, 1973. Despite the dramatic decrease in infectious particles, the number of enveloped HSV particles is not significantly decreased, indicating production of morphologically intact enveloped particles without infectivity (Courtney et al, 1973;Pizer et al, 1980;Katz et al, 1980).…”

O-linked oligosaccharides are acquired by herpes simplex virus glycoproteins in the Golgi apparatus

“…Cells infected with herpes simplex virus provide a useful system for investigating the processes discussed above. Previous studies have shown that glycoproteins specified by herpes simplex virus type 1 (HSVl) contain O-linked oligosaccharides (Oloffson et al, 1981) as well as N-linked oligosaccharides (Pizer et al, 1980;Serafini-Cessi and Campadelli-Fiume, 1981;Person et al, 1982;Wenske et al, 1982). We have confirmed these findings, further characterized the O-linked oligosaccharides and shown that 3H-palmitate is incorporated into one of the HSVl glycoproteins.…”