Anatomy of herpes simplex virus DNA VII. alpha-RNA is homologous to noncontiguous sites in both the L and S components of viral DNA

Abstract

Previous reports operationally defined .alpha. polypeptides as the viral proteins that are synthesized 1st in HEp-2 cells treated with cycloheximide from the time of infection with herpes simplex virus type 1 until the withdrawal of the drug 12-15 h after infection. The viral RNA(designated .alpha. RNA) that accumulates in the cytoplasm during cycloheximide treatment and on polyribosomes immediately on withdrawal of the drug is homologous to 10-12% of viral DNA, but the viral RNA accumulating in the cytoplasm of untreated cells at 8-14 h after infection is homologous to 43% of viral DNA. The .alpha. RNA and cytoplasmic RNA extracted from untreated cells 8 h after infection were each hybridized in liquid to in vitro labeled restriction endonuclease fragments generated by cleavage of herpes simplex virus type 1 DNA with HsuI, [from Haemophilus suis] BglII [from Bacillus lobigii] and with both enzymes simultaneously. Only a subset of the fragments hybridized to .alpha. RNA, and these are scattered within the L and S components of the DNA. These are at least 5 noncontiguous regions in the DNA homologous to .alpha. RNA; 2 of these are located partially within the reiterated sequences in the S component. All fragments tested hybridized more extensively with 8-h cytoplasmic RNA than with .alpha. RNA. Four adjacent fragments, corresponding to 30% of the DNA and mapping within the L component, hybridized exclusively with the cytoplasmic RNA extracted from cells 8 h after infection.