Abstract
The human foamy or spumaretrovirus HFV is a complex and exogenous retrovirus that encodes several bel genes besides the three classical retroviral genes gag, pol, and env. HFV was recently reported to contain two functionally active promoters that are both strongly trans-activated by the HFV trans-activator protein Bel 1. The occurrence of a second internal cap site underscores the complexity of the HFV genome. We have analysed whether there is interference between the HFV long terminal repeat promoter and the internal promoter located in the 3' end of env upstream of the bel genes. Recombinant clones were constructed that carry two different indicator genes, one under the control of the U3 promoter, the other under the control of the internal promoter. The portion of the basal transcriptional activity of the internal promoter that is not trans-activated by Bel 1 was increased two- to threefold in the presence of the long terminal repeat promoter. The rate of trans-activation by Bel 1 of both HFV promoters was not altered in these constructs.
Full text
PDF




Images in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Achong B. G., Mansell P. W., Epstein M. A., Clifford P. An unusual virus in cultures from a human nasopharyngeal carcinoma. J Natl Cancer Inst. 1971 Feb;46(2):299–307. [PubMed] [Google Scholar]
- Berger J., Hauber J., Hauber R., Geiger R., Cullen B. R. Secreted placental alkaline phosphatase: a powerful new quantitative indicator of gene expression in eukaryotic cells. Gene. 1988 Jun 15;66(1):1–10. doi: 10.1016/0378-1119(88)90219-3. [DOI] [PubMed] [Google Scholar]
- Bothe K., Aguzzi A., Lassmann H., Rethwilm A., Horak I. Progressive encephalopathy and myopathy in transgenic mice expressing human foamy virus genes. Science. 1991 Aug 2;253(5019):555–557. doi: 10.1126/science.1650034. [DOI] [PubMed] [Google Scholar]
- Cullen B. R. Human immunodeficiency virus as a prototypic complex retrovirus. J Virol. 1991 Mar;65(3):1053–1056. doi: 10.1128/jvi.65.3.1053-1056.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cullen B. R., Lomedico P. T., Ju G. Transcriptional interference in avian retroviruses--implications for the promoter insertion model of leukaemogenesis. Nature. 1984 Jan 19;307(5948):241–245. doi: 10.1038/307241a0. [DOI] [PubMed] [Google Scholar]
- Flügel R. M., Rethwilm A., Maurer B., Darai G. Nucleotide sequence analysis of the env gene and its flanking regions of the human spumaretrovirus reveals two novel genes. EMBO J. 1987 Jul;6(7):2077–2084. doi: 10.1002/j.1460-2075.1987.tb02473.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Flügel R. M. Spumaviruses: a group of complex retroviruses. J Acquir Immune Defic Syndr. 1991;4(8):739–750. [PubMed] [Google Scholar]
- Keller A., Garrett E. D., Cullen B. R. The Bel-1 protein of human foamy virus activates human immunodeficiency virus type 1 gene expression via a novel DNA target site. J Virol. 1992 Jun;66(6):3946–3949. doi: 10.1128/jvi.66.6.3946-3949.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Keller A., Partin K. M., Löchelt M., Bannert H., Flügel R. M., Cullen B. R. Characterization of the transcriptional trans activator of human foamy retrovirus. J Virol. 1991 May;65(5):2589–2594. doi: 10.1128/jvi.65.5.2589-2594.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lee A. H., Lee K. J., Kim S., Sung Y. C. Transactivation of human immunodeficiency virus type 1 long terminal repeat-directed gene expression by the human foamy virus bel1 protein requires a specific DNA sequence. J Virol. 1992 May;66(5):3236–3240. doi: 10.1128/jvi.66.5.3236-3240.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Löchelt M., Zentgraf H., Flügel R. M. Construction of an infectious DNA clone of the full-length human spumaretrovirus genome and mutagenesis of the bel 1 gene. Virology. 1991 Sep;184(1):43–54. doi: 10.1016/0042-6822(91)90820-2. [DOI] [PubMed] [Google Scholar]
- Mahnke C., Kashaiya P., Rössler J., Bannert H., Levin A., Blattner W. A., Dietrich M., Luande J., Löchelt M., Friedman-Kien A. E. Human spumavirus antibodies in sera from African patients. Arch Virol. 1992;123(3-4):243–253. doi: 10.1007/BF01317261. [DOI] [PubMed] [Google Scholar]
- Maurer B., Bannert H., Darai G., Flügel R. M. Analysis of the primary structure of the long terminal repeat and the gag and pol genes of the human spumaretrovirus. J Virol. 1988 May;62(5):1590–1597. doi: 10.1128/jvi.62.5.1590-1597.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Miller A. D. Retroviral vectors. Curr Top Microbiol Immunol. 1992;158:1–24. doi: 10.1007/978-3-642-75608-5_1. [DOI] [PubMed] [Google Scholar]
- Muller H. K., Ball G., Epstein M. A., Achong B. G., Lenoir G., Levin A. The prevalence of naturally occurring antibodies to human syncytial virus in East African populations. J Gen Virol. 1980 Apr;47(2):399–406. doi: 10.1099/0022-1317-47-2-399. [DOI] [PubMed] [Google Scholar]
- Muranyi W., Flügel R. M. Analysis of splicing patterns of human spumaretrovirus by polymerase chain reaction reveals complex RNA structures. J Virol. 1991 Feb;65(2):727–735. doi: 10.1128/jvi.65.2.727-735.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rethwilm A., Erlwein O., Baunach G., Maurer B., ter Meulen V. The transcriptional transactivator of human foamy virus maps to the bel 1 genomic region. Proc Natl Acad Sci U S A. 1991 Feb 1;88(3):941–945. doi: 10.1073/pnas.88.3.941. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Venkatesh L. K., Theodorakis P. A., Chinnadurai G. Distinct cis-acting regions in U3 regulate trans-activation of the human spumaretrovirus long terminal repeat by the viral bel1 gene product. Nucleic Acids Res. 1991 Jul 11;19(13):3661–3666. doi: 10.1093/nar/19.13.3661. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Weiss R. A. Foamy retroviruses. A virus in search of a disease. Nature. 1988 Jun 9;333(6173):497–498. doi: 10.1038/333497a0. [DOI] [PubMed] [Google Scholar]