Transcription from the CaMV 19 S promoter and autocatalysis of translation from CaMV RNA.
The 19 S promoter of cauliflower mosaic virus was analyzed in host protoplasts. In spite of its weakness, it contains a fully functional core promoter. It can be strongly activated by 35 S enhancer elements, even when these elements are located downstream of it, comparable to the situation in the viral genome. The 19 S promoter also contains an element that can strongly enhance expression from a heterologous core promoter. A plasmid expressing the same CAT ORF from two overlapping transcription units, a dicistronic one under control of the 35 S promoter and a monocistronic one under control of the 19 S promoter, was constructed. While in the absence of the virus ORF VI product (pVI, "transactivator") only low levels of CAT activity deriving from the 19 S promoter were observed, in the presence of this protein high levels of CAT activity derived from the 35 S unit were observed in addition. This suggests autocatalytic activation of pVI expression during virus infection.
Driesen
M
M
Friedrich Miescher Institute, Basel, Switzerland.
Benito-Moreno
R M
RM
Hohn
T
T
Fütterer
J
J
D002384:Catalysis; D004742:Enhancer Elements, Genetic; D015967:Gene Expression Regulation, Viral; D009029:Mosaic Viruses / Q000235:genetics*; D016296:Mutagenesis; D016366:Open Reading Frames; D011401:Promoter Regions, Genetic; D014176:Protein Biosynthesis; D011523:Protoplasts; D012367:RNA, Viral / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic; D015533:Transcriptional Activation
D012367:RNA, Viral