Posttranscriptional trans-activation in cauliflower mosaic virus

Cell. 1989 Dec 22;59(6):1135-43. doi: 10.1016/0092-8674(89)90769-1.


The ability of plant cells to translate dicistronic mRNAs that mimic a segment of the polycistronic 35S RNA from cauliflower mosaic virus has been tested. The chloramphenicol acetyltransferase and beta-glucuronidase open reading frames (ORFs) were fused in-frame to the second viral cistron (ORF I). Efficient reporter expression from the corresponding plasmids in plant protoplasts was observed only upon cotransfection with viral DNA. The trans-activating gene maps at ORF VI, which is expressed from a separate, monocistronic messenger (19S RNA). Deletion analysis shows that trans-activation selectively enhances downstream gene expression; the high expression of the upstream ORF is not further increased. The major reporter transcript remained bicistronic upon trans-activation, and its abundance varied only to a limited extent. Results indicate that trans-activation enhances the translation of downstream ORFs on polycistronic mRNAs derived from cauliflower mosaic virus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Brassica / genetics
  • Genes*
  • Genes, Viral*
  • Molecular Sequence Data
  • Mosaic Viruses / genetics*
  • Mutation
  • Plants / genetics
  • Plasmids
  • Protoplasts / physiology
  • RNA Processing, Post-Transcriptional*
  • RNA, Messenger / genetics
  • Transcriptional Activation*


  • RNA, Messenger