scholarly journals Hepatitis B Virus-X Downregulates Expression of Selenium Binding Protein 1

Viruses ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 565 ◽  
Author(s):  
Young-Man Lee ◽  
Soojin Kim ◽  
Ran-Young Park ◽  
Yeon-Soo Kim
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Binding Protein ◽  
Tissue Microarrays ◽  
Rt Pcr ◽  
Human Liver Tissue ◽  
Promoter Sequences ◽  
Tumor Tissues ◽  
B Virus ◽  
Reporter Gene Analysis

Selenium binding protein 1 (SELENBP1) has been known to be reduced in various types cancer, and epigenetic change is shown to be likely to account for the reduction of SELNEBP1 expression. With cDNA microarray comparative analysis, we found that SELENBP1 is markedly decreased in hepatitis B virus-X (HBx)-expressing cells. To clarify the effect of HBx on SELENBP1 expression, we compared the expression levels of SELENBP1 mRNA and protein by semi-quantitative RT-PCR, Northern blot, and Western blot. As expected, SELENBP1 expression was shown to be reduced in cells expressing HBx, and reporter gene analysis showed that the SELENBP1 promoter is repressed by HBx. In addition, the stepwise deletion of 5′ flanking promoter sequences resulted in a gradual decrease in basal promoter activity and inhibition of SELENBP1 expression by HBx. Moreover, immunohistochemistry on tissue microarrays containing 60 pairs of human liver tissue showed decreased intensity of SELENBP1 in tumor tissues as compared with their matched non-tumor liver tissues. Taken together, our findings suggest that inhibition of SELENBP1 expression by HBx might act as one of the causes in the development of hepatocellular carcinoma caused by HBV infection.

scholarly journals RMP, a Novel RNA Polymerase II Subunit 5-Interacting Protein, Counteracts Transactivation by Hepatitis B Virus X Protein

1998 ◽  
Vol 18 (12) ◽  
pp. 7546-7555 ◽  
Author(s):  
Dorjbal Dorjsuren ◽  
Yong Lin ◽  
Wenxiang Wei ◽  
Tatsuya Yamashita ◽  
Takahiro Nomura ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Binding Protein ◽  
Host Protein ◽  
Dependent Manner ◽  
Binding Region ◽  
X Protein ◽  
B Virus

ABSTRACT To modulate transcription, regulatory factors communicate with basal transcription factors and/or RNA polymerases in a variety of ways. Previously, it has been reported that RNA polymerase II subunit 5 (RPB5) is one of the targets of hepatitis B virus X protein (HBx) and that both HBx and RPB5 specifically interact with general transcription factor IIB (TFIIB), implying that RPB5 is one of the communicating subunits of RNA polymerase II involved in transcriptional regulation. In this context, we screened for a host protein(s) that interacts with RPB5. By far-Western blot screening, we cloned a novel gene encoding a 508-amino-acid-residue RPB5-binding protein from a HepG2 cDNA library and designated it RPB5-mediating protein (RMP). Expression of RMP mRNA was detected ubiquitously in various tissues. Bacterially expressed recombinant RMP strongly bound RPB5 but neither HBx nor TATA-binding protein in vitro. Endogenous RMP was immunologically detected interacting with assembled RPB5 in RNA polymerase in mammalian cells. The central part of RMP is responsible for RPB5 binding, and the RMP-binding region covers both the TFIIB- and HBx-binding sites of RPB5. Overexpression of RMP, but not mutant RMP lacking the RPB5-binding region, inhibited HBx transactivation of reporters with different HBx-responsive cis elements in transiently transfected cells. The repression by RMP was counteracted by HBx in a dose-dependent manner. Furthermore, RMP has an inhibitory effect on transcriptional activation by VP16 in the absence of HBx. These results suggest that RMP negatively modulates RNA polymerase II function by binding to RPB5 and that HBx counteracts the negative role of RMP on transcription indirectly by interacting with RPB5.

scholarly journals A Sensitive and Rapid Assay for Investigating Vertical Transmission of Hepatitis B Virus via Male Germ Line Using EGFP Vector as Reporter

2008 ◽  
Vol 2008 ◽  
pp. 1-6 ◽  
Author(s):  
Mohamed Morsi M. Ahmed ◽  
Tian-Hua Huang ◽  
Qing-Dong Xie
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Vertical Transmission ◽  
Germ Line ◽  
Dna Recombination ◽  
Green Fluorescence ◽  
Rt Pcr ◽  
Male Germ Line ◽  
Rapid Assay ◽  
B Virus

Hepatitis B virus (HBV) constitutes a serious menace to man. DNA recombination and sequencing, interspecific in vitro fertilization, single-embryo PCR and RT-PCR were employed to establish a sensitive and rapid assay for exploring the vertical transmission of viruses via male germ line. Plasmid pIRES2-EGFP-HBs which expressed enhanced green fluorescent protein as reporter for the expression of hepatitis B virusSgene was successfully constructed and confirmed by PCR, EcoR I and Sal I digestion, and DNA sequencing. After exposure to the plasmid, human spermatozoa were used to fertilize with zona-free hamster ova. Two-cell embryos were collected and classified into group A with green fluorescence and group B without green fluorescence under fluorescence microscope. The results showed that HBs DNA positive bands were detected in the embryos with green fluorescence (PCR and RT-PCR) and positive control (PCR) indicating expression of pIRES2-EGFP-HBs, and not observed in the embryos without green fluorescence and negative controls (PCR and RT-PCR) indicating no pIRES2-EGFP-HBs in the cells. The advantages and application foreground of this assay for study on vertical transmission of viruses such as HCV, HIV, HPV, and SARS via germ line were discussed.

Evolution of viral load and changes of polymerase and precore/core promoter sequences in lamivudine-resistant hepatitis B virus during adefovir therapy

2007 ◽  
Vol 79 (7) ◽  
pp. 902-910 ◽  
Author(s):  
U Im Chang ◽  
Young Chun Lee ◽  
Seong Heon Wie ◽  
Jeong Won Jang ◽  
Si Hyun Bae ◽  
...  
Keyword(s):  
Viral Load ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Core Promoter ◽  
Promoter Sequences ◽  
B Virus

scholarly journals Protein-x of hepatitis B virus in interaction with CCAAT/enhancer-binding protein α (C/EBPα) - an in silico analysis approach

2011 ◽  
Vol 8 (1) ◽  
pp. 41 ◽  
Author(s):  
Ashraf Mohamadkhani ◽  
Parisa Shahnazari ◽  
Zarrin Minuchehr ◽  
Armin Madadkar-Sobhani ◽  
Mahmoud Tehrani ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
In Silico ◽  
Binding Protein ◽  
In Silico Analysis ◽  
Analysis Approach ◽  
Enhancer Binding Protein ◽  
B Virus ◽  
Protein X ◽  
Silico Analysis

scholarly journals Genotyping Hepatitis B virus from whole- and sub-genomic fragments using position-specific scoring matrices in hbv star

2006 ◽  
Vol 87 (6) ◽  
pp. 1459-1464 ◽  
Author(s):  
Richard Myers ◽  
Caroline Clark ◽  
Arshad Khan ◽  
Paul Kellam ◽  
Richard Tedder
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Core Promoter ◽  
Full Length ◽  
Basal Core Promoter ◽  
Hbv Genotype ◽  
Promoter Sequences ◽  
Hbv Genotypes ◽  
Scoring Matrices ◽  
B Virus

Hepatitis B virus (HBV) genomes have been classified into eight genotypes based on phylogenetic analysis of sequence variation. Identifying and tracking the movement of HBV genotypes is important in terms of both monitoring infection rates and predicting disease and treatment. An HBV genotyping tool has been developed that compares query sequences with position-specific scoring matrices representing the eight HBV genotypes. This tool (hbv star) is rapid, robust and accurate and assigns genotype based on a statistically defined scoring model. hbv star confidently assigned 90 % of 590 full-length HBV genomes to an HBV genotype (Z score >2.0). Thirty-two of the residual 48 sequences were identified as non-human primate viruses and 16 sequences were identified as recombinant or putative recombinants. Receiver-Operated Characteristic (ROC) analysis was used to compare the accuracy of genotype prediction using basal core promoter sequences and surface and core genes with the accuracy achieved by using full-length sequences. A web interface to hbv star is available at http://www.vgb.ucl.ac.uk/starn.shtml.

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