Identification of protein-binding sites in the hepatitis B virus enhancer and core promoter domains

1988 ◽  
Vol 8 (12) ◽  
pp. 5159-5165
Author(s):  
S Karpen ◽  
R Banerjee ◽  
A Zelent ◽  
P Price ◽  
G Acs
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Binding Sites ◽  
Core Promoter ◽  
Nuclear Extract ◽  
Mobility Shift ◽  
B Virus ◽  
Gel Mobility Shift ◽  
Enhancer Sequences ◽  
Cat Gene

We have investigated the role of liver-specific trans-acting factor(s) in the regulation of hepatitis B virus (HBV) gene expression. A recorder plasmid (pEcoAluCAT; HBV nucleotides 1 through 1878) was constructed containing the HBV enhancer and the promoter region of the pregenomic RNA, which was ligated to the bacterial chloramphenicol acetyltransferase (CAT) gene. Upon transfecting this plasmid into various cell lines, the CAT gene was expressed only in cells of liver origin. Moreover, competition cotransfections with pEcoAluCAT and plasmids containing HBV enhancer sequences in human hepatoblastoma-derived HepG2 cells indicated the presence of titratable trans-acting factor(s) in these cells. Gel mobility shift assays using HBV enhancer and core promoter domains confirmed the existence of sequence-specific DNA-binding proteins in liver cell nuclear extract which bound to these regions. These binding sites encompass 17- and 12-nucleotide palindromes in the HBV enhancer and core promoter domains, respectively, when mapped by the methylation interference assay.

scholarly journals Identification of protein-binding sites in the hepatitis B virus enhancer and core promoter domains.

1988 ◽  
Vol 8 (12) ◽  
pp. 5159-5165 ◽  
Author(s):  
S Karpen ◽  
R Banerjee ◽  
A Zelent ◽  
P Price ◽  
G Acs
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Binding Sites ◽  
Core Promoter ◽  
Nuclear Extract ◽  
Mobility Shift ◽  
B Virus ◽  
Gel Mobility Shift ◽  
Enhancer Sequences ◽  
Cat Gene

We have investigated the role of liver-specific trans-acting factor(s) in the regulation of hepatitis B virus (HBV) gene expression. A recorder plasmid (pEcoAluCAT; HBV nucleotides 1 through 1878) was constructed containing the HBV enhancer and the promoter region of the pregenomic RNA, which was ligated to the bacterial chloramphenicol acetyltransferase (CAT) gene. Upon transfecting this plasmid into various cell lines, the CAT gene was expressed only in cells of liver origin. Moreover, competition cotransfections with pEcoAluCAT and plasmids containing HBV enhancer sequences in human hepatoblastoma-derived HepG2 cells indicated the presence of titratable trans-acting factor(s) in these cells. Gel mobility shift assays using HBV enhancer and core promoter domains confirmed the existence of sequence-specific DNA-binding proteins in liver cell nuclear extract which bound to these regions. These binding sites encompass 17- and 12-nucleotide palindromes in the HBV enhancer and core promoter domains, respectively, when mapped by the methylation interference assay.

scholarly journals The Hepatitis B Virus Core Promoter Is Strongly Activated by the Liver Nuclear Receptor Fetoprotein Transcription Factor or by Ectopically Expressed Steroidogenic Factor 1

2000 ◽  
Vol 74 (11) ◽  
pp. 5032-5039 ◽  
Author(s):  
Stéphane Gilbert ◽  
Luc Galarneau ◽  
Alain Lamontagne ◽  
Sylvie Roy ◽  
Luc Bélanger
Keyword(s):  
Transcription Factor ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Nuclear Receptor ◽  
Binding Sites ◽  
Core Promoter ◽  
Steroidogenic Factor 1 ◽  
High Affinity ◽  
The Core ◽  
B Virus

ABSTRACT Orphan nuclear receptor fetoprotein transcription factor (FTF) was previously identified as a specific regulator of the α1-fetoprotein gene during early liver development and in response to hormonal signals (L. Galarneau, J.-F. Paré, D. Allard, D. Hamel, L. Lévesque, J. D. Tugwood, S. Green, and L. Bélanger, Mol. Cell. Biol. 16:3853–3865, 1996). Here we report a functional analysis of FTF interactions with the hepatitis B virus (HBV) nucleocapsid promoter. DNA-protein-binding assays show that the HBV core promoter contains two high-affinity FTF-binding sites and a third, lower-affinity site shared with other receptors. Transfections in HepG2, Hep3B, and PLC/PRF/5 hepatoma cells using chloramphenicol acetyltransferase reporter genes with the nucleocapsid promoter linked or not linked to enhancer I indicate that FTF is a potent activator of the HBV core promoter, more efficient than HNF4α, HNF3α, HNF3β, or C/EBPα. Steroidogenic factor 1, a close FTF homolog which binds to the same DNA motif and is expressed ectopically in HepG2 cells, seems to be an even stronger inducer than FTF. Point mutations of the FTF-binding sites indicate direct FTF activatory effects on the core promoter and the use of both high-affinity sites for productive interaction between the core promoter and enhancer I. Coexpression assays further indicate that FTF and HNF4α are the most efficient partners for coactivation of the pregenomic core promoter, which may largely account for the hepatic tropism and the early amplification of HBV infection. Carboxy terminus-truncated FTF behaves as a dominant negative mutant to compete all three FTF sites and strongly deactivate core promoter interactions with enhancer I; this suggests possible new ways to interfere with HBV infection.

scholarly journals Differential Regulation of Hepatitis B Virus Gene Expression by the Sp1 Transcription Factor

2001 ◽  
Vol 75 (18) ◽  
pp. 8400-8406 ◽  
Author(s):  
Jie Li ◽  
Jing-hsiung Ou
Keyword(s):  
Gene Expression ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Binding Sites ◽  
Core Promoter ◽  
Differential Regulation ◽  
The Core ◽  
S Gene ◽  
B Virus ◽  
X Gene

ABSTRACT The expression of hepatitis B virus (HBV) genes is regulated by a number of transcription factors. One such factor, Sp1, has two binding sites in the core promoter and one in its upstream regulatory element, which is also known as the ENII enhancer. In this study, we have analyzed the effects of these three Sp1 binding sites on the expression of HBV genes. Our results indicate that both Sp1 binding sites in the core promoter are important for the transcription of the core RNA and the precore RNA. Moreover, while the downstream Sp1 site (the Sp1-1 site) in the core promoter did not affect the transcription of the S gene and the X gene, the upstream Sp1 site (the Sp1-2 site) in the core promoter was found to negatively regulate the transcription of the S gene and the X gene, as removal of the latter led to enhancement of transcription of these two genes. The Sp1 binding site in the ENII enhancer (the Sp1-3 site) positively regulates the expression of all of the HBV genes, as its removal by mutation suppressed the expression of all of the HBV genes. However, the suppressive effect of the Sp1-3 site mutation on the expression of the S gene and the X gene was abolished if the two Sp1 sites in the core promoter were also mutated. These results indicate that Sp1 can serve both as a positive regulator and as a negative regulator for the expression of HBV genes. This dual activity may be important for the differential regulation of HBV gene expression.

Precore/Core Promoter Mutant Hepatitis B Virus Produces More Severe Histologic Liver Disease than Wild Type Hepatitis B Virus

2007 ◽  
Vol 1 (1) ◽  
pp. 41-46 ◽  
Author(s):  
Mamun-Al-Mahtab ◽  
Salimur Rahman ◽  
Mobin Khan ◽  
Ayub Mamun ◽  
Kamal
Keyword(s):  
Liver Disease ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Core Promoter ◽  
Wild Type ◽  
B Virus ◽  
Promoter Mutant

scholarly journals Prevalence of Hepatitis B Virus Subgenotypes and Basal Core Promoter, Precore Variants in Patients with Acute Hepatitis B in Central Vietnam

Intervirology ◽  
2009 ◽  
Vol 52 (1) ◽  
pp. 22-28 ◽  
Author(s):  
Kazuhiko Hayashi ◽  
Yoshiaki Katano ◽  
Tran Xuan Chuong ◽  
Yasushi Takeda ◽  
Masatoshi Ishigami ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Acute Hepatitis ◽  
Core Promoter ◽  
Basal Core Promoter ◽  
Central Vietnam ◽  
B Virus ◽  
Acute Hepatitis B

Identification of a promoter element located upstream from the hepatitis B virus X gene

1987 ◽  
Vol 7 (1) ◽  
pp. 545-548
Author(s):  
M Treinin ◽  
O Laub
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Gene Promoter ◽  
Maximal Activity ◽  
Enhancer Element ◽  
B Virus ◽  
X Gene ◽  
Rna Mapping ◽  
Active Promoter ◽  
Cat Gene

We have analyzed a series of plasmids in which the sequences located upstream from the hepatitis B virus (HBV) X gene were linked to the chloramphenicol acetyl transferase (CAT) gene. Expression of the marker CAT gene in transfected cells clearly demonstrated that sequences preceding the X gene contain an active promoter. RNA mapping by primer extension indicated that the RNA encoded by the X gene promoter initiates at multiple sites spanning nucleotides 1250 to 1350 on the HBV genome. Deletion within the adjacent HBV enhancer element region significantly reduced the activity of the X gene promoter, suggesting that the X gene promoter requires the enhancer element for maximal activity.

Sign in / Sign up

Export Citation Format

Share Document