|
|
||||||||
Department of Plant Sciences, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel 69778
Correspondence
Bernard L. Epel
blepel{at}post.tau.ac.il
A replicon based on Tobacco mosaic virus that was engineered to express the open reading frame (ORF) of the green fluorescent protein (GFP) gene in place of the native coat protein (CP) gene from a minimal CP subgenomic (sg) RNA promoter was found to accumulate very low levels of GFP. Regulatory regions within the CP ORF were identified that, when presented as untranslated regions flanking the GFP ORF, enhanced or inhibited sg transcription and GFP expression. Full GFP expression from the CP sgRNA promoter required more than the first 20 nt of the CP ORF but not beyond the first 56 nt. Further analysis indicated the presence of an enhancer element between nt +25 and +55 with respect to the CP translation start site. The inclusion of this enhancer sequence upstream of the GFP ORF led to elevated sg transcription and to a 50-fold increase in GFP accumulation in comparison with a minimal CP promoter in which the entire CP ORF was displaced by the GFP ORF. Inclusion of the 3'-terminal 22 nt had a minor positive effect on GFP accumulation, but the addition of extended untranslated sequences from the 3' terminus of the CP ORF downstream of the GFP ORF was basically found to inhibit sg transcription. Secondary structure analysis programs predicted the CP sgRNA promoter to reside within two stable stemloop structures, which are followed by an enhancer region.
This article has been cited by other articles:
![]() |
Yu. L. Dorokhov, P. A. Ivanov, T. V. Komarova, M. V. Skulachev, and J. G. Atabekov An internal ribosome entry site located upstream of the crucifer-infecting tobamovirus coat protein (CP) gene can be used for CP synthesis in vivo J. Gen. Virol., September 1, 2006; 87(9): 2693 - 2697. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| INT J SYST EVOL MICROBIOL | MICROBIOLOGY | J GEN VIROL |
| J MED MICROBIOL | ALL SGM JOURNALS | |