The regulation of human immunodeficiency virus (HIV) gene expression is dependent on specific regulatory sequences in the long terminal repeat. Elements that appear to be important for regulation of viral gene expression include IL-2-like enhancer sequences, negative regulatory elements, an enhancer containing two NF-kB motifs, three SP1 binding sites, the TATA element, and the TAR region. These regulatory sequences serve as the binding sites for cellular transcription factors. A number of cellular proteins that bind to these DNA sites have been characterized including NFAT-1, which binds to the IL-2 like enhancer elements; EBP-1 and NF-kB, which bind to the enhancer, SP-1, which binds to the three SP1 binding sites; UBP-1 or LBP, UBP-2, and CTF which bind to the TAR region. In addition to these regulatory sequences, the viral regulatory protein, tat, acts to enhance viral gene expression. The goal of this grant is to understand how these regulatory elements and their binding proteins function in activating HIV gene expression. Several approaches will be undertaken to address these questions. First, infectious viral constructs containing mutations in various LTR regulatory domains will be studied to determine the effects of these mutations on viral growth. Second, the role of the TAR region on tat activation of the HIV LTR will be determined by nuclear run-on experiments using the HIV LTR, a variety of heterologous TAR constructs, and DNA and RNA competition experiments. Third, we will investigate the role of cloned cellular factors that bind to IL-2 like enhancer sequences, the enhancer, and UBP-L binding sites in the TAR region on the regulation of HIV gene expression. Finally, the role of mutant tat proteins on regulating viral gene expression will be investigated. These studies should further define cellular and viral regulatory mechanisms that mediate HIV gene expression.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
2R01AI025288-04
Application #
3138711
Study Section
Special Emphasis Panel (ARR (V1))
Project Start
1987-09-01
Project End
1991-07-31
Budget Start
1990-09-01
Budget End
1991-07-31
Support Year
4
Fiscal Year
1990
Total Cost
Indirect Cost
Name
University of California Los Angeles
Department
Type
Schools of Medicine
DUNS #
119132785
City
Los Angeles
State
CA
Country
United States
Zip Code
90095
Widlak, P; Gaynor, R B; Garrard, W T (1997) In vitro chromatin assembly of the HIV-1 promoter. ATP-dependent polar repositioning of nucleosomes by Sp1 and NFkappaB. J Biol Chem 272:17654-61
Harrich, D; Garcia, J; Mitsuyasu, R et al. (1990) TAR independent activation of the human immunodeficiency virus in phorbol ester stimulated T lymphocytes. EMBO J 9:4417-23
Garcia, J A; Harrich, D; Soultanakis, E et al. (1989) Human immunodeficiency virus type 1 LTR TATA and TAR region sequences required for transcriptional regulation. EMBO J 8:765-78
Kliewer, S; Garcia, J; Pearson, L et al. (1989) Multiple transcriptional regulatory domains in the human immunodeficiency virus type 1 long terminal repeat are involved in basal and E1A/E1B-induced promoter activity. J Virol 63:4616-25
Harrich, D; Garcia, J; Wu, F et al. (1989) Role of SP1-binding domains in in vivo transcriptional regulation of the human immunodeficiency virus type 1 long terminal repeat. J Virol 63:2585-91
Gaynor, R; Soultanakis, E; Kuwabara, M et al. (1989) Specific binding of a HeLa cell nuclear protein to RNA sequences in the human immunodeficiency virus transactivating region. Proc Natl Acad Sci U S A 86:4858-62
Wu, F K; Garcia, J A; Harrich, D et al. (1988) Purification of the human immunodeficiency virus type 1 enhancer and TAR binding proteins EBP-1 and UBP-1. EMBO J 7:2117-30
Gaynor, R B; Kuwabara, M D; Wu, F K et al. (1988) Repeated B motifs in the human immunodeficiency virus type I long terminal repeat enhancer region do not exhibit cooperative factor binding. Proc Natl Acad Sci U S A 85:9406-10