The general objective of this project is to elucidate the molecular mechanisms of Tat transactivation during transcription initiation. Localization of discrete Tat functional domains active in transcription initiation will be determined by site-directed mutagenesis and evaluation of Tat mutants on HIV transcription at different stages of pre-initiation and initiation and by construction and evaluation of GAL4/Tat fusion proteins for their effect on HIV transcription in vitro and in vivo. Dissection of the mechanism(s) by which Tat enhances pre-initiation complex formation during HIV transcription will be accomplished by determination of association and disassociation rates of pre-initiation complex assembly using gel shift and footprinting assays, by determination of Tat-protein interactions using co-immunoprecipitation assays, co-sedimentation analysis, protein filter binding, Tat affinity chromatography and by determination of Tat effects on functional activities of pre-initiation complex components. Determination of Tat-mediated effects on the synthetic step of transcription initiation will be afforded by quantitating the abundance of the first dinucleotide synthesized upon transcription initiation from productive pre-initiation complexes.
| Wang, Z; Morris, G F; Reed, J C et al. (1999) Activation of Bcl-2 promoter-directed gene expression by the human immunodeficiency virus type-1 Tat protein. Virology 257:502-10 |
| Yang, L; Morris, G F; Wang, Z et al. (1997) Repression of tumor necrosis factor-beta expression by the human immunodeficiency virus type-1 tat protein in central nervous system-derived glial cells. Virus Res 50:195-203 |
| Yang, L; Morris, G F; Lockyer, J M et al. (1997) Distinct transcriptional pathways of TAR-dependent and TAR-independent human immunodeficiency virus type-1 transactivation by Tat. Virology 235:48-64 |
| Tsang, S X; Morris, G F; Lu, M et al. (1996) TATA-dependent repression of human immunodeficiency virus type-1 transcription by the adenovirus E1A 243R oncoprotein. Oncogene 12:819-26 |
| Morris, C B; Gendelman, R; Marrogi, A J et al. (1996) Immunihistochemical detection of Bcl-2 in AIDS-associated and classical Kaposi's sarcoma. Am J Pathol 148:1055-63 |
