INTERMEDIATE FORMS OF GLYCOCONJUGATES ARE PRESENT IN THE ENVELOPE OF HERPES-SIMPLEX VIRIONS DURING THEIR TRANSPORT ALONG THE EXOCYTIC PATHWAY

In cells infected with herpes simplex virus 1, intracellular virions i n transit along the exocytic pathway carry glycoconjugates that react, in fracture-label technique, with helix pomatia lectin. This lectin i s specific for unsubstituted N-acetylgalactosamine, an intermediate su gar added in O-linkage to ser/thr residues in cis-Golgi and then subst ituted with galactose and sialic acid in the trans-Golgi. Virions in t he perinuclear space do not react with helix pomatia lectin. In intrac ellular transport vesicles and vacuoles, close to the Golgi complex, v irions are positively labeled by helix pomatia lectin and variably lab eled by wheat germ agglutinin, a lectin specific for fully mature glyc oconjugates. Extracellular virions react only with wheat germ agglutin in. The detection of glycoconjugates at intermediate steps of maturati on, coupled with previous results that virions in the perinuclear spac e carry high mannose oligosaccharides (Torrisi et al., J. Virol. 66, 5 54-561, 1992), favor the view that maturation of herpes simplex virion envelope proceeds in a stepwise manner along the exocytic pathway. Sh ould transit of virions involve a deenvelopment of enveloped virions f ollowed by reenvelopment of naked nucleocapsids, our results rule out reenvelopment at trans- or post-Golgi compartments and could be consis tent with reenvelopment occurring earlier in the exocytic pathway, mos t likely at the cis-Golgi. (C) 1995 Academic Press, Inc.