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. 1992 Jul;66(7):4065–4072. doi: 10.1128/jvi.66.7.4065-4072.1992

Human immunodeficiency virus type 1 Tat-mediated trans activation correlates with the phosphorylation state of a cellular TAR RNA stem-binding factor.

X M Han 1, A Laras 1, M P Rounseville 1, A Kumar 1, P R Shank 1
PMCID: PMC241209  PMID: 1602533

Abstract

Protein kinase C (PKC) is involved in the mitogenic stimulation of cell proliferation and has recently been reported to be essential for Tat-mediated trans activation. We have determined that RNA binding of a cellular factor which specifically interacts with the trans-activation response region (TAR) is blocked in cells depleted of PKC activity by chronic phorbol myristate acetate stimulation. We also show that nuclear extracts can be depleted of the cellular TAR-binding factor by in vitro treatment with purified protein phosphatase 2A. Furthermore, TAR RNA-binding activity can be partially restored to depleted nuclear extracts in vitro by addition of PKC. Chimeric constructs in which the Tat protein is artificially tethered to viral RNA show PKC independence for Tat-mediated trans activation. Specific mutations in the TAR RNA stem region which cause reduced binding of host cell factor in vitro also cause reduced Tat-mediated trans activation in vivo. Together, these results suggest that phosphorylation-dependent binding of a cellular cofactor to TAR RNA is an essential step in Tat-mediated trans activation. Deciphering the regulation of Tat-mediated trans activation by phosphorylation will be critical in fully understanding the regulation of human immunodeficiency virus type 1 activation.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Baeuerle P. A., Baltimore D. I kappa B: a specific inhibitor of the NF-kappa B transcription factor. Science. 1988 Oct 28;242(4878):540–546. doi: 10.1126/science.3140380. [DOI] [PubMed] [Google Scholar]
  2. Berkhout B., Gatignol A., Rabson A. B., Jeang K. T. TAR-independent activation of the HIV-1 LTR: evidence that tat requires specific regions of the promoter. Cell. 1990 Aug 24;62(4):757–767. doi: 10.1016/0092-8674(90)90120-4. [DOI] [PubMed] [Google Scholar]
  3. Berkhout B., Jeang K. T. trans activation of human immunodeficiency virus type 1 is sequence specific for both the single-stranded bulge and loop of the trans-acting-responsive hairpin: a quantitative analysis. J Virol. 1989 Dec;63(12):5501–5504. doi: 10.1128/jvi.63.12.5501-5504.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Berkhout B., Silverman R. H., Jeang K. T. Tat trans-activates the human immunodeficiency virus through a nascent RNA target. Cell. 1989 Oct 20;59(2):273–282. doi: 10.1016/0092-8674(89)90289-4. [DOI] [PubMed] [Google Scholar]
  5. Braddock M., Thorburn A. M., Chambers A., Elliott G. D., Anderson G. J., Kingsman A. J., Kingsman S. M. A nuclear translational block imposed by the HIV-1 U3 region is relieved by the Tat-TAR interaction. Cell. 1990 Sep 21;62(6):1123–1133. doi: 10.1016/0092-8674(90)90389-v. [DOI] [PubMed] [Google Scholar]
  6. Burns D. J., Bloomenthal J., Lee M. H., Bell R. M. Expression of the alpha, beta II, and gamma protein kinase C isozymes in the baculovirus-insect cell expression system. Purification and characterization of the individual isoforms. J Biol Chem. 1990 Jul 15;265(20):12044–12051. [PubMed] [Google Scholar]
  7. Carey J., Lowary P. T., Uhlenbeck O. C. Interaction of R17 coat protein with synthetic variants of its ribonucleic acid binding site. Biochemistry. 1983 Sep 27;22(20):4723–4730. doi: 10.1021/bi00289a017. [DOI] [PubMed] [Google Scholar]
  8. 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]
  9. 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]
  10. Dingwall C., Ernberg I., Gait M. J., Green S. M., Heaphy S., Karn J., Lowe A. D., Singh M., Skinner M. A., Valerio R. Human immunodeficiency virus 1 tat protein binds trans-activation-responsive region (TAR) RNA in vitro. Proc Natl Acad Sci U S A. 1989 Sep;86(18):6925–6929. doi: 10.1073/pnas.86.18.6925. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Dinter H., Chiu R., Imagawa M., Karin M., Jones K. A. In vitro activation of the HIV-1 enhancer in extracts from cells treated with a phorbol ester tumor promoter. EMBO J. 1987 Dec 20;6(13):4067–4071. doi: 10.1002/j.1460-2075.1987.tb02752.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Folks T., Kelly J., Benn S., Kinter A., Justement J., Gold J., Redfield R., Sell K. W., Fauci A. S. Susceptibility of normal human lymphocytes to infection with HTLV-III/LAV. J Immunol. 1986 Jun 1;136(11):4049–4053. [PubMed] [Google Scholar]
  13. Gatignol A., Buckler-White A., Berkhout B., Jeang K. T. Characterization of a human TAR RNA-binding protein that activates the HIV-1 LTR. Science. 1991 Mar 29;251(5001):1597–1600. doi: 10.1126/science.2011739. [DOI] [PubMed] [Google Scholar]
  14. Gatignol A., Kumar A., Rabson A., Jeang K. T. Identification of cellular proteins that bind to the human immunodeficiency virus type 1 trans-activation-responsive TAR element RNA. Proc Natl Acad Sci U S A. 1989 Oct;86(20):7828–7832. doi: 10.1073/pnas.86.20.7828. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Gendelman H. E., Phelps W., Feigenbaum L., Ostrove J. M., Adachi A., Howley P. M., Khoury G., Ginsberg H. S., Martin M. A. Trans-activation of the human immunodeficiency virus long terminal repeat sequence by DNA viruses. Proc Natl Acad Sci U S A. 1986 Dec;83(24):9759–9763. doi: 10.1073/pnas.83.24.9759. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Jackson S. P., MacDonald J. J., Lees-Miller S., Tjian R. GC box binding induces phosphorylation of Sp1 by a DNA-dependent protein kinase. Cell. 1990 Oct 5;63(1):155–165. doi: 10.1016/0092-8674(90)90296-q. [DOI] [PubMed] [Google Scholar]
  17. Jakobovits A., Rosenthal A., Capon D. J. Trans-activation of HIV-1 LTR-directed gene expression by tat requires protein kinase C. EMBO J. 1990 Apr;9(4):1165–1170. doi: 10.1002/j.1460-2075.1990.tb08223.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. 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]
  19. Jeang K. T., Shank P. R., Kumar A. Transcriptional activation of homologous viral long terminal repeats by the human immunodeficiency virus type 1 or the human T-cell leukemia virus type I tat proteins occurs in the absence of de novo protein synthesis. Proc Natl Acad Sci U S A. 1988 Nov;85(21):8291–8295. doi: 10.1073/pnas.85.21.8291. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Kaufman J. D., Valandra G., Roderiquez G., Bushar G., Giri C., Norcross M. A. Phorbol ester enhances human immunodeficiency virus-promoted gene expression and acts on a repeated 10-base-pair functional enhancer element. Mol Cell Biol. 1987 Oct;7(10):3759–3766. doi: 10.1128/mcb.7.10.3759. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. MacKintosh C., Beattie K. A., Klumpp S., Cohen P., Codd G. A. Cyanobacterial microcystin-LR is a potent and specific inhibitor of protein phosphatases 1 and 2A from both mammals and higher plants. FEBS Lett. 1990 May 21;264(2):187–192. doi: 10.1016/0014-5793(90)80245-e. [DOI] [PubMed] [Google Scholar]
  22. Manger B., Weiss A., Imboden J., Laing T., Stobo J. D. The role of protein kinase C in transmembrane signaling by the T cell antigen receptor complex. Effects of stimulation with soluble or immobilized CD3 antibodies. J Immunol. 1987 Oct 15;139(8):2755–2760. [PubMed] [Google Scholar]
  23. Marciniak R. A., Calnan B. J., Frankel A. D., Sharp P. A. HIV-1 Tat protein trans-activates transcription in vitro. Cell. 1990 Nov 16;63(4):791–802. doi: 10.1016/0092-8674(90)90145-5. [DOI] [PubMed] [Google Scholar]
  24. Marciniak R. A., Garcia-Blanco M. A., Sharp P. A. Identification and characterization of a HeLa nuclear protein that specifically binds to the trans-activation-response (TAR) element of human immunodeficiency virus. Proc Natl Acad Sci U S A. 1990 May;87(9):3624–3628. doi: 10.1073/pnas.87.9.3624. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. McDougal J. S., Mawle A., Cort S. P., Nicholson J. K., Cross G. D., Scheppler-Campbell J. A., Hicks D., Sligh J. Cellular tropism of the human retrovirus HTLV-III/LAV. I. Role of T cell activation and expression of the T4 antigen. J Immunol. 1985 Nov;135(5):3151–3162. [PubMed] [Google Scholar]
  26. 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]
  27. Newstein M., Stanbridge E. J., Casey G., Shank P. R. Human chromosome 12 encodes a species-specific factor which increases human immunodeficiency virus type 1 tat-mediated trans activation in rodent cells. J Virol. 1990 Sep;64(9):4565–4567. doi: 10.1128/jvi.64.9.4565-4567.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Rounseville M. P., Kumar A. Binding of a host cell nuclear protein to the stem region of human immunodeficiency virus type 1 trans-activation-responsive RNA. J Virol. 1992 Mar;66(3):1688–1694. doi: 10.1128/jvi.66.3.1688-1694.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Roy S., Delling U., Chen C. H., Rosen C. A., Sonenberg N. A bulge structure in HIV-1 TAR RNA is required for Tat binding and Tat-mediated trans-activation. Genes Dev. 1990 Aug;4(8):1365–1373. doi: 10.1101/gad.4.8.1365. [DOI] [PubMed] [Google Scholar]
  30. Selby M. J., Peterlin B. M. Trans-activation by HIV-1 Tat via a heterologous RNA binding protein. Cell. 1990 Aug 24;62(4):769–776. doi: 10.1016/0092-8674(90)90121-t. [DOI] [PubMed] [Google Scholar]
  31. Sheline C. T., Milocco L. H., Jones K. A. Two distinct nuclear transcription factors recognize loop and bulge residues of the HIV-1 TAR RNA hairpin. Genes Dev. 1991 Dec;5(12B):2508–2520. doi: 10.1101/gad.5.12b.2508. [DOI] [PubMed] [Google Scholar]
  32. Siekevitz M., Josephs S. F., Dukovich M., Peffer N., Wong-Staal F., Greene W. C. Activation of the HIV-1 LTR by T cell mitogens and the trans-activator protein of HTLV-I. Science. 1987 Dec 11;238(4833):1575–1578. doi: 10.1126/science.2825351. [DOI] [PubMed] [Google Scholar]
  33. Southgate C., Zapp M. L., Green M. R. Activation of transcription by HIV-1 Tat protein tethered to nascent RNA through another protein. Nature. 1990 Jun 14;345(6276):640–642. doi: 10.1038/345640a0. [DOI] [PubMed] [Google Scholar]
  34. Tong-Starksen S. E., Luciw P. A., Peterlin B. M. Human immunodeficiency virus long terminal repeat responds to T-cell activation signals. Proc Natl Acad Sci U S A. 1987 Oct;84(19):6845–6849. doi: 10.1073/pnas.84.19.6845. [DOI] [PMC free article] [PubMed] [Google Scholar]
  35. Weeks K. M., Ampe C., Schultz S. C., Steitz T. A., Crothers D. M. Fragments of the HIV-1 Tat protein specifically bind TAR RNA. Science. 1990 Sep 14;249(4974):1281–1285. doi: 10.1126/science.2205002. [DOI] [PubMed] [Google Scholar]
  36. Wu F., Garcia J., Sigman D., Gaynor R. tat regulates binding of the human immunodeficiency virus trans-activating region RNA loop-binding protein TRP-185. Genes Dev. 1991 Nov;5(11):2128–2140. doi: 10.1101/gad.5.11.2128. [DOI] [PubMed] [Google Scholar]
  37. Yasuda I., Kishimoto A., Tanaka S., Tominaga M., Sakurai A., Nishizuka Y. A synthetic peptide substrate for selective assay of protein kinase C. Biochem Biophys Res Commun. 1990 Feb 14;166(3):1220–1227. doi: 10.1016/0006-291x(90)90996-z. [DOI] [PubMed] [Google Scholar]
  38. Zagury D., Bernard J., Leonard R., Cheynier R., Feldman M., Sarin P. S., Gallo R. C. Long-term cultures of HTLV-III--infected T cells: a model of cytopathology of T-cell depletion in AIDS. Science. 1986 Feb 21;231(4740):850–853. doi: 10.1126/science.2418502. [DOI] [PubMed] [Google Scholar]
  39. Zapp M. L., Green M. R. Sequence-specific RNA binding by the HIV-1 Rev protein. Nature. 1989 Dec 7;342(6250):714–716. doi: 10.1038/342714a0. [DOI] [PubMed] [Google Scholar]

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