Abstract

The human immunodeficiency virus type 1 (HIV-1) transactivator Tat protein is essential for efficient viral gene expression and virus replication. We have previously shown that Tat interacts with the basal transcription factor TFIID. This interaction is mediated through the amino acid 36-50 core domain of Tat. We now demonstrate that soluble peptide analogs of the Tat core domain are able to effectively block LTR transactivation. In cotransfection experiments, Tat peptide analogs inhibited Tat transactivation of an HIV-1 LTR-CAT reporter construct up to 80-fold. In contrast, inhibition of other promoters such as HTLV-I and CMV was approximately two-fold. One of the Tat peptide analogs, containing amino acid substitutions at position 41 and 44, inhibited HIV virus replication by 85 percent in latently infected U1 cells induced with Tat. While both short and long peptide analogs (amino acids 36-50 vs 36-72) inhibited Tat transactivation in transient assays, the short peptides were more effective inhibitors of virus replication in U1 cells. Furthermore, U1 cells treated with the Tat peptide 36-50 (41/44) analog showed markedly delayed virus transmission when co-cultivated with parental U937 cells. The Tat peptide analog did not decrease expression of cellular genes including -actin, GAPDH and histone H2b. Finally, it is demonstrated that the Tat peptide analog inhibits Tat transactivation through a TBP-activated pathway using a minimal HIV promoter.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Intramural Research (Z01)
Project #
1Z01BC005753-05
Application #
6160966
Study Section
Special Emphasis Panel (LRBG)
Project Start
Project End
Budget Start
Budget End
Support Year
5
Fiscal Year
1997
Total Cost
Indirect Cost

  Institution

Name
National Cancer Institute Division of Basic Sciences
Department
Type
DUNS #
City
State
Country
United States
Zip Code

  Publications

Bonome, Tomas; Levine, Douglas A; Shih, Joanna et al. (2008) A gene signature predicting for survival in suboptimally debulked patients with ovarian cancer. Cancer Res 68:5478-86
Gegonne, Anne; Weissman, Jocelyn D; Lu, Hanxin et al. (2008) TFIID component TAF7 functionally interacts with both TFIIH and P-TEFb. Proc Natl Acad Sci U S A 105:5367-72
Cho, Won-Kyung; Zhou, Meisheng; Jang, Moon Kyoo et al. (2007) Modulation of the Brd4/P-TEFb interaction by the human T-lymphotropic virus type 1 tax protein. J Virol 81:11179-86
Zhou, Meisheng; Lu, Hanxin; Park, Hyeon et al. (2006) Tax interacts with P-TEFb in a novel manner to stimulate human T-lymphotropic virus type 1 transcription. J Virol 80:4781-91
Gegonne, Anne; Weissman, Jocelyn D; Zhou, Meisheng et al. (2006) TAF7: a possible transcription initiation check-point regulator. Proc Natl Acad Sci U S A 103:602-7
Jang, Moon Kyoo; Mochizuki, Kazuki; Zhou, Meisheng et al. (2005) The bromodomain protein Brd4 is a positive regulatory component of P-TEFb and stimulates RNA polymerase II-dependent transcription. Mol Cell 19:523-34
Ammosova, Tatyana; Washington, Kareem; Debebe, Zufan et al. (2005) Dephosphorylation of CDK9 by protein phosphatase 2A and protein phosphatase-1 in Tat-activated HIV-1 transcription. Retrovirology 2:47
Watanabe, Takahiro; Sugaya, Makoto; Atkins, April M et al. (2003) Kaposi's sarcoma-associated herpesvirus latency-associated nuclear antigen prolongs the life span of primary human umbilical vein endothelial cells. J Virol 77:6188-96
Zhou, Meisheng; Deng, Longwen; Kashanchi, Fatah et al. (2003) The Tat/TAR-dependent phosphorylation of RNA polymerase II C-terminal domain stimulates cotranscriptional capping of HIV-1 mRNA. Proc Natl Acad Sci U S A 100:12666-71
Zhou, M; Kashanchi, F; Jiang, H et al. (2000) Phosphorylation of the RAP74 subunit of TFIIF correlates with Tat-activated transcription of the HIV-1 long terminal repeat. Virology 268:452-60

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