Human topoisomerase 1 messenger RNA is not destabilized by the herpes simplex virus type 2 virion-associated shut-off function.

A cDNA for human topoisomerase I (Topo 1) was used to identify a 4.1 kb polyadenylated Topo 1 mRNA in methotrexate-resistant human KB cells that are permissive for herpes simplex virus type 2 (HSV-2) infection. Using these cells, no effect of the HSV-2-associated early shut-off function on levels of Topo-1 mRNA was observed up to 6 hours postinfection, whereas the actin mRNA level was 22% cellular transcripts are susceptible. The level of several host-cell polyadenylated RNAs detected as cDNA clones (class 3 transcripts) were unchanged 8 hours after HSV-2 infection, and other cellular transcripts (class 2) actually accumulated at postinfection.