Effect of melittin on transcription by vesiculovirus mutant and wild-type viruses

The bee venom peptide melittin activated the virion transcriptase activity of three vesiculoviruses with preservation of virion structure. The kinetics of RNA synthesis were similar to those observed with purified transcribing nucleoprotein (TNP) preparations. Six temperature-sensitive host range (tdCE) mutants of Chandipura virus displayed 1.7- to 5.5-fold greater efficiencies of transcription at 39 degrees with melittin-permeabilized virions in comparison with TNP preparations. Comparative study of other host range mutants (tdCE3) and tsB1) of vesicular stomatitis virus (VSV) New Jersey and a thermosensitive polymerase mutant (tsG114) of VSV Indiana suggested that the enhanced transcription at 39 degrees associated with melittin-activated tdCE mutants was due to the retention of host factors in the virions.