Posttranscriptional trans-activation in cauliflower mosaic virus.
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.
Bonneville
J M
JM
Friedrich Miescher-Institut, Basel, Switzerland.
Sanfaçon
H
H
Fütterer
J
J
Hohn
T
T
D001483:Base Sequence; D001937:Brassica / Q000235:genetics; D005796:Genes; D005814:Genes, Viral; D008969:Molecular Sequence Data; D009029:Mosaic Viruses / Q000235:genetics*; D009154:Mutation; D010944:Plants / Q000235:genetics; D010957:Plasmids; D011523:Protoplasts / Q000502:physiology; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000235:genetics; D015533:Transcriptional Activation
D012333:RNA, Messenger