Genotype-dependent activation or repression of HBV enhancer II by transcription factor COUP-TF1.
OBJECTIVE
To study the expression of HBV enhancer II by transcription factor COUP-TF1.


METHODS
In order to study the regulation of HBV variants in the vicinity of the NRRE we cloned luciferase constructs containing the HBV enhancer II from variants and from HBV genotypes A and D and cotransfected them together with expression vectors for COUP-TF1 into HepG2 cells.


RESULTS
Our findings show that enhancer II of HBV genotype A is also repressed by COUP-TF1. In contrast, two different enhancer II constructs of HBV genotype D were activated by COUP-TF1. The activation was independent of the NRRE because a natural variant with a deletion of nt 1763-1770 was still activated by COUP-TF1.


CONCLUSIONS
Regulation of transcription of the HBV genome seems to differ among HBV genomes derived from different genotypes. These differences in transcriptional control among HBV genotypes may be the molecular basis for differences in the clinical course among HBV genotypes.
Fischer
Silke F
SF
Institut für Medizinische Virologie, Justus-Liebig-Universität Giessen, Germany.
Schmidt
Katja
K
Fiedler
Nicola
N
Glebe
Dieter
D
Schüttler
Christian
C
Sun
Jianguang
J
Gerlich
Wolfram H
WH
Repp
Reinald
R
Schaefer
Stephan
S
D001483:Base Sequence; D051838:COUP Transcription Factor I / Q000235:genetics*; D045744:Cell Line, Tumor; D004279:DNA, Viral / Q000235:genetics; D024202:Electrophoretic Mobility Shift Assay; D004742:Enhancer Elements, Genetic / Q000235:genetics*; D017353:Gene Deletion; D015967:Gene Expression Regulation, Viral / Q000235:genetics*; D005838:Genotype; D006515:Hepatitis B virus / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D014162:Transfection
D051838:COUP Transcription Factor I; D004279:DNA, Viral; C497589:NR2F1 protein, human