Detailed analysis of the portion of the herpes simplex virus type 1 genome encoding glycoprotein C

Abstract

The right third of HindIII fragment L (0.59 to 0.65) of herpes simplex virus type 1 (HSV-1) encodes a family of mRNA some members of which appear to be related by splicing. In the experiments described in this communication, the nucleotide sequence of the DNA encoding this mRNA family was determined and the mRNA associated with this DNA sequence were precisely located. The major mRNA species is unspliced and encoded by a 2520-nucleotide region. Just upstream of the 5'' end are TATA and CAT box sequences characteristic of HSV-1 promoters. The 3'' end maps near a region containing a nominal polyadenylation signal. Three minor species (2400, 2200 and 1900 bases, respectively) appear to share a very short leader sequence with the 5'' end of the major mRNA and are then encoded by uninterrupted DNA sequences beginning about 100, 400 and 625 bases downstream of the 5'' end of the major unspliced mRNA. These positions map at or very near positions which agree reasonably well with consensus splice acceptor sequences. The 4th mRNA is encoded by a contiguous 730 nucleotide sequence at the 3'' end of the major unspliced mRNA and has its 5'' end just downstream of recognizable TATA and CAT box sequences. Evidently, mRNA is controlled by its own promoter. The nucleotide sequence data, in combination with the mRNA localization, demonstrate 4 potential polypeptides encoded by the region. The largest is 1569 bases long and defines a 523 amino acid protein with sequence features characteristic of a glycoprotein. This was confirmed to be HSV-1 glycoprotein C by immune precipitation of the in vitro translation product of the major unspliced mRNA, performed with a polyspecific antibody to HSV-1 envelope glycoproteins (anti-env-1 serum), and by comparison of tryptic peptides of this translation product with those of authentic HSV-1 glycoprotein C. Polypeptides encoded by some of the minor species also were tentatively identified.