Abstract
Woodchuck hepatitis virus (WHV) efficiently induces hepatocellular carcinoma in chronically infected hosts. A key step in hepatocarcinogenesis by WHV is insertional activation of the cellular N-myc gene by integrated viral DNA. WHV enhancer II (En II) is the major cis-acting element involved in this activation. Here we characterize this viral enhancer element and define the cellular factors involved in its activity. WHV En II activity is strongly liver specific and maps to an 88-nucleotide DNA segment (nucleotides 1772 to 1859) located 5' to the pregenomic RNA start site. Genetic analyses and electrophoretic mobility shift assays indicate that the enhancer contains three subregions important to its activity. The core elements of the enhancer are recognition sites for the liver-enriched factors HNF1 and HNF4; together, these signals account for the bulk of En II activity as well as its strong liver specificity. Multimerization of either recognition site produced strong activity even in the absence of other En II sequences. 5' to these elements is a binding site for the ubiquitous Oct-1 transcription factor, which further augments enhancer activity ca. twofold.
Full Text
The Full Text of this article is available as a PDF (731.5 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Agre P., Johnson P. F., McKnight S. L. Cognate DNA binding specificity retained after leucine zipper exchange between GCN4 and C/EBP. Science. 1989 Nov 17;246(4932):922–926. doi: 10.1126/science.2530632. [DOI] [PubMed] [Google Scholar]
- Antonucci T. K., Rutter W. J. Hepatitis B virus (HBV) promoters are regulated by the HBV enhancer in a tissue-specific manner. J Virol. 1989 Feb;63(2):579–583. doi: 10.1128/jvi.63.2.579-583.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bach I., Mattei M. G., Cereghini S., Yaniv M. Two members of an HNF1 homeoprotein family are expressed in human liver. Nucleic Acids Res. 1991 Jul 11;19(13):3553–3559. doi: 10.1093/nar/19.13.3553. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Carlsson P., Eriksson P., Bjursell G. Two nuclear proteins bind to the major positive element of the apolipoprotein B gene promoter. Gene. 1990 Oct 15;94(2):295–301. doi: 10.1016/0378-1119(90)90401-c. [DOI] [PubMed] [Google Scholar]
- Chen S. T., La Porte P., Yee J. K. Mutational analysis of hepatitis B virus enhancer 2. Virology. 1993 Oct;196(2):652–659. doi: 10.1006/viro.1993.1521. [DOI] [PubMed] [Google Scholar]
- Cleary M. A., Stern S., Tanaka M., Herr W. Differential positive control by Oct-1 and Oct-2: activation of a transcriptionally silent motif through Oct-1 and VP16 corecruitment. Genes Dev. 1993 Jan;7(1):72–83. doi: 10.1101/gad.7.1.72. [DOI] [PubMed] [Google Scholar]
- Crescenzo-Chaigne B., Pillot J., Lilienbaum A., Levrero M., Elfassi E. Identification of a strong enhancer element upstream from the pregenomic RNA start site of the duck hepatitis B virus genome. J Virol. 1991 Jul;65(7):3882–3886. doi: 10.1128/jvi.65.7.3882-3886.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Descombes P., Schibler U. A liver-enriched transcriptional activator protein, LAP, and a transcriptional inhibitory protein, LIP, are translated from the same mRNA. Cell. 1991 Nov 1;67(3):569–579. doi: 10.1016/0092-8674(91)90531-3. [DOI] [PubMed] [Google Scholar]
- Elfassi E. Broad specificity of the hepatitis B enhancer function. Virology. 1987 Sep;160(1):259–262. doi: 10.1016/0042-6822(87)90069-9. [DOI] [PubMed] [Google Scholar]
- Fourel G., Couturier J., Wei Y., Apiou F., Tiollais P., Buendia M. A. Evidence for long-range oncogene activation by hepadnavirus insertion. EMBO J. 1994 Jun 1;13(11):2526–2534. doi: 10.1002/j.1460-2075.1994.tb06542.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fourel G., Transy C., Tennant B. C., Buendia M. A. Expression of the woodchuck N-myc2 retroposon in brain and in liver tumors is driven by a cryptic N-myc promoter. Mol Cell Biol. 1992 Dec;12(12):5336–5344. doi: 10.1128/mcb.12.12.5336. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fourel G., Trepo C., Bougueleret L., Henglein B., Ponzetto A., Tiollais P., Buendia M. A. Frequent activation of N-myc genes by hepadnavirus insertion in woodchuck liver tumours. Nature. 1990 Sep 20;347(6290):294–298. doi: 10.1038/347294a0. [DOI] [PubMed] [Google Scholar]
- Frain M., Swart G., Monaci P., Nicosia A., Stämpfli S., Frank R., Cortese R. The liver-specific transcription factor LF-B1 contains a highly diverged homeobox DNA binding domain. Cell. 1989 Oct 6;59(1):145–157. doi: 10.1016/0092-8674(89)90877-5. [DOI] [PubMed] [Google Scholar]
- Ganem D., Varmus H. E. The molecular biology of the hepatitis B viruses. Annu Rev Biochem. 1987;56:651–693. doi: 10.1146/annurev.bi.56.070187.003251. [DOI] [PubMed] [Google Scholar]
- Garcia A. D., Ostapchuk P., Hearing P. Functional interaction of nuclear factors EF-C, HNF-4, and RXR alpha with hepatitis B virus enhancer I. J Virol. 1993 Jul;67(7):3940–3950. doi: 10.1128/jvi.67.7.3940-3950.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hall R. K., Sladek F. M., Granner D. K. The orphan receptors COUP-TF and HNF-4 serve as accessory factors required for induction of phosphoenolpyruvate carboxykinase gene transcription by glucocorticoids. Proc Natl Acad Sci U S A. 1995 Jan 17;92(2):412–416. doi: 10.1073/pnas.92.2.412. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hansen L. J., Tennant B. C., Seeger C., Ganem D. Differential activation of myc gene family members in hepatic carcinogenesis by closely related hepatitis B viruses. Mol Cell Biol. 1993 Jan;13(1):659–667. doi: 10.1128/mcb.13.1.659. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hu K. Q., Siddiqui A. Regulation of the hepatitis B virus gene expression by the enhancer element I. Virology. 1991 Apr;181(2):721–726. doi: 10.1016/0042-6822(91)90906-r. [DOI] [PubMed] [Google Scholar]
- Jameel S., Siddiqui A. The human hepatitis B virus enhancer requires trans-acting cellular factor(s) for activity. Mol Cell Biol. 1986 Feb;6(2):710–715. doi: 10.1128/mcb.6.2.710. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Johnson J. L., Raney A. K., McLachlan A. Characterization of a functional hepatocyte nuclear factor 3 binding site in the hepatitis B virus nucleocapsid promoter. Virology. 1995 Apr 1;208(1):147–158. doi: 10.1006/viro.1995.1138. [DOI] [PubMed] [Google Scholar]
- Jones K. A., Kadonaga J. T., Rosenfeld P. J., Kelly T. J., Tjian R. A cellular DNA-binding protein that activates eukaryotic transcription and DNA replication. Cell. 1987 Jan 16;48(1):79–89. doi: 10.1016/0092-8674(87)90358-8. [DOI] [PubMed] [Google Scholar]
- Junker M., Galle P., Schaller H. Expression and replication of the hepatitis B virus genome under foreign promoter control. Nucleic Acids Res. 1987 Dec 23;15(24):10117–10132. doi: 10.1093/nar/15.24.10117. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kemler I., Bucher E., Seipel K., Müller-Immerglück M. M., Schaffner W. Promoters with the octamer DNA motif (ATGCAAAT) can be ubiquitous or cell type-specific depending on binding affinity of the octamer site and Oct-factor concentration. Nucleic Acids Res. 1991 Jan 25;19(2):237–242. doi: 10.1093/nar/19.2.237. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kemler I., Schaffner W. Octamer transcription factors and the cell type-specificity of immunoglobulin gene expression. FASEB J. 1990 Mar;4(5):1444–1449. doi: 10.1096/fasebj.4.5.2407588. [DOI] [PubMed] [Google Scholar]
- Kodama K., Ogasawara N., Yoshikawa H., Murakami S. Nucleotide sequence of a cloned woodchuck hepatitis virus genome: evolutional relationship between hepadnaviruses. J Virol. 1985 Dec;56(3):978–986. doi: 10.1128/jvi.56.3.978-986.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kuo C. J., Conley P. B., Hsieh C. L., Francke U., Crabtree G. R. Molecular cloning, functional expression, and chromosomal localization of mouse hepatocyte nuclear factor 1. Proc Natl Acad Sci U S A. 1990 Dec;87(24):9838–9842. doi: 10.1073/pnas.87.24.9838. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Landschulz W. H., Johnson P. F., Adashi E. Y., Graves B. J., McKnight S. L. Isolation of a recombinant copy of the gene encoding C/EBP. Genes Dev. 1988 Jul;2(7):786–800. doi: 10.1101/gad.2.7.786. [DOI] [PubMed] [Google Scholar]
- Lee W., Mitchell P., Tjian R. Purified transcription factor AP-1 interacts with TPA-inducible enhancer elements. Cell. 1987 Jun 19;49(6):741–752. doi: 10.1016/0092-8674(87)90612-x. [DOI] [PubMed] [Google Scholar]
- Liu C., Mason W. S., Burch J. B. Identification of factor-binding sites in the duck hepatitis B virus enhancer and in vivo effects of enhancer mutations. J Virol. 1994 Apr;68(4):2286–2296. doi: 10.1128/jvi.68.4.2286-2296.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
- López-Cabrera M., Letovsky J., Hu K. Q., Siddiqui A. Transcriptional factor C/EBP binds to and transactivates the enhancer element II of the hepatitis B virus. Virology. 1991 Aug;183(2):825–829. doi: 10.1016/0042-6822(91)91019-d. [DOI] [PubMed] [Google Scholar]
- Mendel D. B., Crabtree G. R. HNF-1, a member of a novel class of dimerizing homeodomain proteins. J Biol Chem. 1991 Jan 15;266(2):677–680. [PubMed] [Google Scholar]
- Mendel D. B., Hansen L. P., Graves M. K., Conley P. B., Crabtree G. R. HNF-1 alpha and HNF-1 beta (vHNF-1) share dimerization and homeo domains, but not activation domains, and form heterodimers in vitro. Genes Dev. 1991 Jun;5(6):1042–1056. doi: 10.1101/gad.5.6.1042. [DOI] [PubMed] [Google Scholar]
- Mendelzon D., Boissier F., Zakin M. M. The binding site for the liver-specific transcription factor Tf-LF1 and the TATA box of the human transferrin gene promoter are the only elements necessary to direct liver-specific transcription in vitro. Nucleic Acids Res. 1990 Oct 11;18(19):5717–5721. doi: 10.1093/nar/18.19.5717. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Miura N., Tanaka K. Analysis of the rat hepatocyte nuclear factor (HNF) 1 gene promoter: synergistic activation by HNF4 and HNF1 proteins. Nucleic Acids Res. 1993 Aug 11;21(16):3731–3736. doi: 10.1093/nar/21.16.3731. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ori A., Atzmony D., Haviv I., Shaul Y. An NF1 motif plays a central role in hepatitis B virus enhancer. Virology. 1994 Nov 1;204(2):600–608. doi: 10.1006/viro.1994.1574. [DOI] [PubMed] [Google Scholar]
- Ori A., Shaul Y. Hepatitis B virus enhancer binds and is activated by the Hepatocyte nuclear factor 3. Virology. 1995 Feb 20;207(1):98–106. doi: 10.1006/viro.1995.1055. [DOI] [PubMed] [Google Scholar]
- Ostapchuk P., Scheirle G., Hearing P. Binding of nuclear factor EF-C to a functional domain of the hepatitis B virus enhancer region. Mol Cell Biol. 1989 Jul;9(7):2787–2797. doi: 10.1128/mcb.9.7.2787. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pearson W. R., Lipman D. J. Improved tools for biological sequence comparison. Proc Natl Acad Sci U S A. 1988 Apr;85(8):2444–2448. doi: 10.1073/pnas.85.8.2444. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Perez-Mutul J., Macchi M., Wasylyk B. Mutational analysis of the contribution of sequence motifs within the IgH enhancer to tissue specific transcriptional activation. Nucleic Acids Res. 1988 Jul 11;16(13):6085–6096. doi: 10.1093/nar/16.13.6085. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Popper H., Roth L., Purcell R. H., Tennant B. C., Gerin J. L. Hepatocarcinogenicity of the woodchuck hepatitis virus. Proc Natl Acad Sci U S A. 1987 Feb;84(3):866–870. doi: 10.1073/pnas.84.3.866. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Raney A. K., Easton A. J., Milich D. R., McLachlan A. Promoter-specific transactivation of hepatitis B virus transcription by a glutamine- and proline-rich domain of hepatocyte nuclear factor 1. J Virol. 1991 Nov;65(11):5774–5781. doi: 10.1128/jvi.65.11.5774-5781.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rey-Campos J., Chouard T., Yaniv M., Cereghini S. vHNF1 is a homeoprotein that activates transcription and forms heterodimers with HNF1. EMBO J. 1991 Jun;10(6):1445–1457. doi: 10.1002/j.1460-2075.1991.tb07665.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Robinson W. S. Molecular events in the pathogenesis of hepadnavirus-associated hepatocellular carcinoma. Annu Rev Med. 1994;45:297–323. doi: 10.1146/annurev.med.45.1.297. [DOI] [PubMed] [Google Scholar]
- Seeger C., Baldwin B., Hornbuckle W. E., Yeager A. E., Tennant B. C., Cote P., Ferrell L., Ganem D., Varmus H. E. Woodchuck hepatitis virus is a more efficient oncogenic agent than ground squirrel hepatitis virus in a common host. J Virol. 1991 Apr;65(4):1673–1679. doi: 10.1128/jvi.65.4.1673-1679.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Seeger C., Baldwin B., Tennant B. C. Expression of infectious woodchuck hepatitis virus in murine and avian fibroblasts. J Virol. 1989 Nov;63(11):4665–4669. doi: 10.1128/jvi.63.11.4665-4669.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Shaul Y., Rutter W. J., Laub O. A human hepatitis B viral enhancer element. EMBO J. 1985 Feb;4(2):427–430. doi: 10.1002/j.1460-2075.1985.tb03646.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Siegrist C. A., Durand B., Emery P., David E., Hearing P., Mach B., Reith W. RFX1 is identical to enhancer factor C and functions as a transactivator of the hepatitis B virus enhancer. Mol Cell Biol. 1993 Oct;13(10):6375–6384. doi: 10.1128/mcb.13.10.6375. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sladek F. M., Zhong W. M., Lai E., Darnell J. E., Jr Liver-enriched transcription factor HNF-4 is a novel member of the steroid hormone receptor superfamily. Genes Dev. 1990 Dec;4(12B):2353–2365. doi: 10.1101/gad.4.12b.2353. [DOI] [PubMed] [Google Scholar]
- Sourdive D. J., Chouard T., Yaniv M. The HNF1 C-terminal domain contributes to transcriptional activity and modulates nuclear localisation. C R Acad Sci III. 1993;316(4):385–394. [PubMed] [Google Scholar]
- Stern S., Herr W. The herpes simplex virus trans-activator VP16 recognizes the Oct-1 homeo domain: evidence for a homeo domain recognition subdomain. Genes Dev. 1991 Dec;5(12B):2555–2566. doi: 10.1101/gad.5.12b.2555. [DOI] [PubMed] [Google Scholar]
- Sturm R. A., Das G., Herr W. The ubiquitous octamer-binding protein Oct-1 contains a POU domain with a homeo box subdomain. Genes Dev. 1988 Dec;2(12A):1582–1599. doi: 10.1101/gad.2.12a.1582. [DOI] [PubMed] [Google Scholar]
- Su H., Yee J. K. Regulation of hepatitis B virus gene expression by its two enhancers. Proc Natl Acad Sci U S A. 1992 Apr 1;89(7):2708–2712. doi: 10.1073/pnas.89.7.2708. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tanaka M., Herr W. Differential transcriptional activation by Oct-1 and Oct-2: interdependent activation domains induce Oct-2 phosphorylation. Cell. 1990 Feb 9;60(3):375–386. doi: 10.1016/0092-8674(90)90589-7. [DOI] [PubMed] [Google Scholar]
- Tanaka M., Lai J. S., Herr W. Promoter-selective activation domains in Oct-1 and Oct-2 direct differential activation of an snRNA and mRNA promoter. Cell. 1992 Feb 21;68(4):755–767. doi: 10.1016/0092-8674(92)90150-b. [DOI] [PubMed] [Google Scholar]
- Theisen M., Behringer R. R., Cadd G. G., Brinster R. L., McKnight G. S. A C/EBP-binding site in the transferrin promoter is essential for expression in the liver but not the brain of transgenic mice. Mol Cell Biol. 1993 Dec;13(12):7666–7676. doi: 10.1128/mcb.13.12.7666. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tognoni A., Cattaneo R., Serfling E., Schaffner W. A novel expression selection approach allows precise mapping of the hepatitis B virus enhancer. Nucleic Acids Res. 1985 Oct 25;13(20):7457–7472. doi: 10.1093/nar/13.20.7457. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Trujillo M. A., Letovsky J., Maguire H. F., Lopez-Cabrera M., Siddiqui A. Functional analysis of a liver-specific enhancer of the hepatitis B virus. Proc Natl Acad Sci U S A. 1991 May 1;88(9):3797–3801. doi: 10.1073/pnas.88.9.3797. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tsai S. Y., Sagami I., Wang H., Tsai M. J., O'Malley B. W. Interactions between a DNA-binding transcription factor (COUP) and a non-DNA binding factor (S300-II). Cell. 1987 Aug 28;50(5):701–709. doi: 10.1016/0092-8674(87)90328-x. [DOI] [PubMed] [Google Scholar]
- Ueda K., Wei Y., Ganem D. Activation of N-myc2 gene expression by cis-acting elements of oncogenic hepadnaviral genomes: key role of enhancer II. Virology. 1996 Mar 1;217(1):413–417. doi: 10.1006/viro.1996.0133. [DOI] [PubMed] [Google Scholar]
- Vannice J. L., Levinson A. D. Properties of the human hepatitis B virus enhancer: position effects and cell-type nonspecificity. J Virol. 1988 Apr;62(4):1305–1313. doi: 10.1128/jvi.62.4.1305-1313.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wang L. H., Tsai S. Y., Cook R. G., Beattie W. G., Tsai M. J., O'Malley B. W. COUP transcription factor is a member of the steroid receptor superfamily. Nature. 1989 Jul 13;340(6229):163–166. doi: 10.1038/340163a0. [DOI] [PubMed] [Google Scholar]
- Wei Y., Fourel G., Ponzetto A., Silvestro M., Tiollais P., Buendia M. A. Hepadnavirus integration: mechanisms of activation of the N-myc2 retrotransposon in woodchuck liver tumors. J Virol. 1992 Sep;66(9):5265–5276. doi: 10.1128/jvi.66.9.5265-5276.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wijnholds J., Philipsen J. N., Ab G. Tissue-specific and steroid-dependent interaction of transcription factors with the oestrogen-inducible apoVLDL II promoter in vivo. EMBO J. 1988 Sep;7(9):2757–2763. doi: 10.1002/j.1460-2075.1988.tb03130.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Williams S. C., Cantwell C. A., Johnson P. F. A family of C/EBP-related proteins capable of forming covalently linked leucine zipper dimers in vitro. Genes Dev. 1991 Sep;5(9):1553–1567. doi: 10.1101/gad.5.9.1553. [DOI] [PubMed] [Google Scholar]
- Yee J. K. A liver-specific enhancer in the core promoter region of human hepatitis B virus. Science. 1989 Nov 3;246(4930):658–661. doi: 10.1126/science.2554495. [DOI] [PubMed] [Google Scholar]
- Yuh C. H., Chang Y. L., Ting L. P. Transcriptional regulation of precore and pregenomic RNAs of hepatitis B virus. J Virol. 1992 Jul;66(7):4073–4084. doi: 10.1128/jvi.66.7.4073-4084.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Yuh C. H., Ting L. P. C/EBP-like proteins binding to the functional box-alpha and box-beta of the second enhancer of hepatitis B virus. Mol Cell Biol. 1991 Oct;11(10):5044–5052. doi: 10.1128/mcb.11.10.5044. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Yuh C. H., Ting L. P. Differentiated liver cell specificity of the second enhancer of hepatitis B virus. J Virol. 1993 Jan;67(1):142–149. doi: 10.1128/jvi.67.1.142-149.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Yuh C. H., Ting L. P. The genome of hepatitis B virus contains a second enhancer: cooperation of two elements within this enhancer is required for its function. J Virol. 1990 Sep;64(9):4281–4287. doi: 10.1128/jvi.64.9.4281-4287.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]