Alternate translation initiation on hepatitis B virus X mRNA produces multiple polypeptides that differentially transactivate class II and III promoters

Kwee, L., Lucito, R., Aufiero, B., Schneider, R. J. (July 1992) Alternate translation initiation on hepatitis B virus X mRNA produces multiple polypeptides that differentially transactivate class II and III promoters. J Virol, 66 (7). pp. 4382-9.

URL: http://jvi.asm.org/cgi/content/abstract/66/7/4382

Abstract

The hepatitis B virus X gene encodes a transcription activator which stimulates the synthesis of RNAs from a variety of class II and III promoter elements. In this report, we present a mutational analysis which genetically demonstrates that the X gene actually encodes two, and possibly three, related polypeptides from a single mRNA using alternate translation initiation from any of three in-frame AUG codons. Genetic analysis shows that translation initiates at the 5' proximal AUG of X mRNA and produces a full-length 17-kDa X protein but in addition also likely initiates at either of two conserved, in-frame AUG codons, producing two amino-terminally truncated X proteins presumably of 8 and 6.6 kDa. Expression of mRNAs capable of encoding only one of each X protein all individually transactivate class III (RNA polymerase III)-transcribed promoters. However, class II (RNA polymerase II)-transcribed promoters displayed various requirements for the different X proteins. Expression of two X proteins, the 17- and 6.6-kDa species, was required to activate transcription of the simian virus 40 enhancer/early promoter. In contrast, activation of an NF-kappa B-dependent promoter was carried out only by mRNAs encoding the full-length 17-kDa X protein. These results indicate that the X gene encodes several related proteins that possess different transcriptional regulatory activities.

Item Type: Paper
Uncontrolled Keywords: Codon Enhancer Elements Genetics Hepatitis B virus genetics NF-kappa B metabolism Peptides genetics metabolism Promoter Regions Genetics Protein Biosynthesis Protein Conformation RNA Messenger metabolism RNA Viral metabolism Simian virus 40 genetics Trans-Activation Genetics Trans-Activators genetics metabolism
Subjects: bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > RNA expression
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > DNA, RNA structure, function, modification > mRNA dynamics
organism description > virus
CSHL Authors:
Communities: CSHL labs > Lucito lab
Depositing User: Brian Soldo
Date: July 1992
Date Deposited: 29 Mar 2012 14:54
Last Modified: 29 Mar 2012 14:54
URI: http://repository.cshl.edu/id/eprint/25560

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