Abstract
The transactivator protein, tat, encoded by the human immunodeficiency virus is a key regulator of viral transcription. Activation by the tat protein requires sequences downstream of the transcription initiation site called the transactivating region (TAR). RNA derived from the TAR is capable of forming a stable stem-loop structure and the maintenance of both the stem structure and the loop sequences located between +19 and +44 is required for complete in vivo activation by tat. Gel retardation assays with RNA from both wild-type and mutant TAR constructs generated in vitro with SP6 polymerase indicated specific binding of HeLa nuclear proteins to the TAR. To characterize this RNA-protein interaction, a method of chemical "imprinting" has been developed using photoactivated uranyl acetate as the nucleolytic agent. This reagent nicks RNA under physiological conditions at all four nucleotides in a reaction that is independent of sequence and secondary structure. Specific interaction of cellular proteins with TAR RNA could be detected by enhanced cleavages or imprints surrounding the loop region. Mutations that either disrupted stem base-pairing or extensively changed the primary sequence resulted in alterations in the cleavage pattern of the TAR RNA. Structural features of the TAR RNA stem-loop essential for tat activation are also required for specific binding of the HeLa cell nuclear protein.
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Selected References
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- Ahmad N., Venkatesan S. Nef protein of HIV-1 is a transcriptional repressor of HIV-1 LTR. Science. 1988 Sep 16;241(4872):1481–1485. doi: 10.1126/science.3262235. [DOI] [PubMed] [Google Scholar]
- Arya S. K., Guo C., Josephs S. F., Wong-Staal F. Trans-activator gene of human T-lymphotropic virus type III (HTLV-III). Science. 1985 Jul 5;229(4708):69–73. doi: 10.1126/science.2990040. [DOI] [PubMed] [Google Scholar]
- Berk A. J. Adenovirus promoters and E1A transactivation. Annu Rev Genet. 1986;20:45–79. doi: 10.1146/annurev.ge.20.120186.000401. [DOI] [PubMed] [Google Scholar]
- Cullen B. R. Trans-activation of human immunodeficiency virus occurs via a bimodal mechanism. Cell. 1986 Sep 26;46(7):973–982. doi: 10.1016/0092-8674(86)90696-3. [DOI] [PubMed] [Google Scholar]
- Dayton A. I., Sodroski J. G., Rosen C. A., Goh W. C., Haseltine W. A. The trans-activator gene of the human T cell lymphotropic virus type III is required for replication. Cell. 1986 Mar 28;44(6):941–947. doi: 10.1016/0092-8674(86)90017-6. [DOI] [PubMed] [Google Scholar]
- Dignam J. D., Lebovitz R. M., Roeder R. G. Accurate transcription initiation by RNA polymerase II in a soluble extract from isolated mammalian nuclei. Nucleic Acids Res. 1983 Mar 11;11(5):1475–1489. doi: 10.1093/nar/11.5.1475. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Edery I., Petryshyn R., Sonenberg N. Activation of double-stranded RNA-dependent kinase (dsl) by the TAR region of HIV-1 mRNA: a novel translational control mechanism. Cell. 1989 Jan 27;56(2):303–312. doi: 10.1016/0092-8674(89)90904-5. [DOI] [PubMed] [Google Scholar]
- Feinberg M. B., Jarrett R. F., Aldovini A., Gallo R. C., Wong-Staal F. HTLV-III expression and production involve complex regulation at the levels of splicing and translation of viral RNA. Cell. 1986 Sep 12;46(6):807–817. doi: 10.1016/0092-8674(86)90062-0. [DOI] [PubMed] [Google Scholar]
- Feng S., Holland E. C. HIV-1 tat trans-activation requires the loop sequence within tar. Nature. 1988 Jul 14;334(6178):165–167. doi: 10.1038/334165a0. [DOI] [PubMed] [Google Scholar]
- Fisher A. G., Feinberg M. B., Josephs S. F., Harper M. E., Marselle L. M., Reyes G., Gonda M. A., Aldovini A., Debouk C., Gallo R. C. The trans-activator gene of HTLV-III is essential for virus replication. 1986 Mar 27-Apr 2Nature. 320(6060):367–371. doi: 10.1038/320367a0. [DOI] [PubMed] [Google Scholar]
- Garcia J. A., Harrich D., Pearson L., Mitsuyasu R., Gaynor R. B. Functional domains required for tat-induced transcriptional activation of the HIV-1 long terminal repeat. EMBO J. 1988 Oct;7(10):3143–3147. doi: 10.1002/j.1460-2075.1988.tb03181.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Garcia J. A., Harrich D., Soultanakis E., Wu F., Mitsuyasu R., Gaynor R. B. Human immunodeficiency virus type 1 LTR TATA and TAR region sequences required for transcriptional regulation. EMBO J. 1989 Mar;8(3):765–778. doi: 10.1002/j.1460-2075.1989.tb03437.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Garcia J. A., Wu F. K., Mitsuyasu R., Gaynor R. B. Interactions of cellular proteins involved in the transcriptional regulation of the human immunodeficiency virus. EMBO J. 1987 Dec 1;6(12):3761–3770. doi: 10.1002/j.1460-2075.1987.tb02711.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hauber J., Cullen B. R. Mutational analysis of the trans-activation-responsive region of the human immunodeficiency virus type I long terminal repeat. J Virol. 1988 Mar;62(3):673–679. doi: 10.1128/jvi.62.3.673-679.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hauber J., Perkins A., Heimer E. P., Cullen B. R. Trans-activation of human immunodeficiency virus gene expression is mediated by nuclear events. Proc Natl Acad Sci U S A. 1987 Sep;84(18):6364–6368. doi: 10.1073/pnas.84.18.6364. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jakobovits A., Smith D. H., Jakobovits E. B., Capon D. J. A discrete element 3' of human immunodeficiency virus 1 (HIV-1) and HIV-2 mRNA initiation sites mediates transcriptional activation by an HIV trans activator. Mol Cell Biol. 1988 Jun;8(6):2555–2561. doi: 10.1128/mcb.8.6.2555. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jones K. A., Kadonaga J. T., Luciw P. A., Tjian R. Activation of the AIDS retrovirus promoter by the cellular transcription factor, Sp1. Science. 1986 May 9;232(4751):755–759. doi: 10.1126/science.3008338. [DOI] [PubMed] [Google Scholar]
- Jones K. A., Luciw P. A., Duchange N. Structural arrangements of transcription control domains within the 5'-untranslated leader regions of the HIV-1 and HIV-2 promoters. Genes Dev. 1988 Sep;2(9):1101–1114. doi: 10.1101/gad.2.9.1101. [DOI] [PubMed] [Google Scholar]
- Kao S. Y., Calman A. F., Luciw P. A., Peterlin B. M. Anti-termination of transcription within the long terminal repeat of HIV-1 by tat gene product. Nature. 1987 Dec 3;330(6147):489–493. doi: 10.1038/330489a0. [DOI] [PubMed] [Google Scholar]
- Kawakami K., Scheidereit C., Roeder R. G. Identification and purification of a human immunoglobulin-enhancer-binding protein (NF-kappa B) that activates transcription from a human immunodeficiency virus type 1 promoter in vitro. Proc Natl Acad Sci U S A. 1988 Jul;85(13):4700–4704. doi: 10.1073/pnas.85.13.4700. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kuwabara M. D., Sigman D. S. Footprinting DNA-protein complexes in situ following gel retardation assays using 1,10-phenanthroline-copper ion: Escherichia coli RNA polymerase-lac promoter complexes. Biochemistry. 1987 Nov 17;26(23):7234–7238. doi: 10.1021/bi00397a006. [DOI] [PubMed] [Google Scholar]
- Leibold E. A., Munro H. N. Cytoplasmic protein binds in vitro to a highly conserved sequence in the 5' untranslated region of ferritin heavy- and light-subunit mRNAs. Proc Natl Acad Sci U S A. 1988 Apr;85(7):2171–2175. doi: 10.1073/pnas.85.7.2171. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Muesing M. A., Smith D. H., Capon D. J. Regulation of mRNA accumulation by a human immunodeficiency virus trans-activator protein. Cell. 1987 Feb 27;48(4):691–701. doi: 10.1016/0092-8674(87)90247-9. [DOI] [PubMed] [Google Scholar]
- Nabel G., Baltimore D. An inducible transcription factor activates expression of human immunodeficiency virus in T cells. Nature. 1987 Apr 16;326(6114):711–713. doi: 10.1038/326711a0. [DOI] [PubMed] [Google Scholar]
- Nielsen P. E., Jeppesen C., Buchardt O. Uranyl salts as photochemical agents for cleavage of DNA and probing of protein-DNA contacts. FEBS Lett. 1988 Aug 1;235(1-2):122–124. doi: 10.1016/0014-5793(88)81245-6. [DOI] [PubMed] [Google Scholar]
- Okamoto T., Wong-Staal F. Demonstration of virus-specific transcriptional activator(s) in cells infected with HTLV-III by an in vitro cell-free system. Cell. 1986 Oct 10;47(1):29–35. doi: 10.1016/0092-8674(86)90363-6. [DOI] [PubMed] [Google Scholar]
- Peterlin B. M., Luciw P. A., Barr P. J., Walker M. D. Elevated levels of mRNA can account for the trans-activation of human immunodeficiency virus. Proc Natl Acad Sci U S A. 1986 Dec;83(24):9734–9738. doi: 10.1073/pnas.83.24.9734. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rice A. P., Mathews M. B. Transcriptional but not translational regulation of HIV-1 by the tat gene product. Nature. 1988 Apr 7;332(6164):551–553. doi: 10.1038/332551a0. [DOI] [PubMed] [Google Scholar]
- Rosen C. A., Sodroski J. G., Goh W. C., Dayton A. I., Lippke J., Haseltine W. A. Post-transcriptional regulation accounts for the trans-activation of the human T-lymphotropic virus type III. Nature. 1986 Feb 13;319(6054):555–559. doi: 10.1038/319555a0. [DOI] [PubMed] [Google Scholar]
- Rosen C. A., Sodroski J. G., Haseltine W. A. The location of cis-acting regulatory sequences in the human T cell lymphotropic virus type III (HTLV-III/LAV) long terminal repeat. Cell. 1985 Jul;41(3):813–823. doi: 10.1016/s0092-8674(85)80062-3. [DOI] [PubMed] [Google Scholar]
- Sodroski J., Goh W. C., Rosen C., Dayton A., Terwilliger E., Haseltine W. A second post-transcriptional trans-activator gene required for HTLV-III replication. Nature. 1986 May 22;321(6068):412–417. doi: 10.1038/321412a0. [DOI] [PubMed] [Google Scholar]
- Tullius T. D., Dombroski B. A. Hydroxyl radical "footprinting": high-resolution information about DNA-protein contacts and application to lambda repressor and Cro protein. Proc Natl Acad Sci U S A. 1986 Aug;83(15):5469–5473. doi: 10.1073/pnas.83.15.5469. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wu F. K., Garcia J. A., Harrich D., Gaynor R. B. Purification of the human immunodeficiency virus type 1 enhancer and TAR binding proteins EBP-1 and UBP-1. EMBO J. 1988 Jul;7(7):2117–2130. doi: 10.1002/j.1460-2075.1988.tb03051.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wu F., Garcia J., Mitsuyasu R., Gaynor R. Alterations in binding characteristics of the human immunodeficiency virus enhancer factor. J Virol. 1988 Jan;62(1):218–225. doi: 10.1128/jvi.62.1.218-225.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]