CHARACTERIZATION OF HERPES-SIMPLEX VIRUS TYPE-1 RECOMBINANTS WITH MUTATIONS IN THE CYTOPLASMIC TAIL OF GLYCOPROTEIN-H

Herpes simplex virus (HSV) type 1 glycoprotein H is essential for fusi on of virus envelopes with cellular membranes and for the fusion of an infected cell membrane with an uninfected neighbour. Previous studies have pointed to a requirement for certain amino acid residues of the cytoplasmic tail of gH in these processes. Results from transient tran sfection experiments suggested that the serine-valine-proline (SVP) mo tif in the cytoplasmic tail may be important for gH-mediated fusion. H SV recombinants expressing gH molecules with mutations in the cytoplas mic tail were constructed and analysed in terms of their abilities to fuse cellular membranes and to function in virus entry. Viruses contai ning a deletion of the SVP motif, or in which the valine residue of th is triplet was replaced by alanine, entered cells less efficiently tha n wild-type virus and were unable to induce syncytium formation on Ver o cells.