Interaction of host cell proteins with the human T-cell leukemia virus type I transcriptional control region. II. A comprehensive map of protein-binding sites facilitates construction of a simple chimeric promoter responsive to the viral tax2 gene product.
We present a map describing the binding of cellular proteins to a 300-base pair (bp) region of the human T-cell leukemia virus type I (HTLV-I) long terminal repeat. The map accounts for nearly all of the DNase I protection reported in a previous study using crude nuclear extracts. Notable features include a complex arrangement of overlapping binding sites encompassing the 21-bp repeat elements (see accompanying paper) as well as binding sites for the transcription factors Sp1 and NF-I that significantly deviate from the previously defined consensus recognition sequences. Based on the binding results, we constructed simple chimeric promoters containing 21-bp repeat elements, Sp1-, and nuclear factor I-binding sites upstream of a TATA box. Transient transfection experiments show that these promoters are expressed in T-cells and are regulated by the viral tax2 gene product. Deletion of the Sp1 and nuclear factor I sites abolishes tax-induction, suggesting that one or both of these proteins play a role in mediating the tax-responsiveness conferred by the 21-bp repeat element.
Department of Chemistry and Biochemistry, University of Colorado, Boulder 80309.
J K
JK
Nyborg
M A
MA
Matthews
J
J
Yucel
L
L
Walls
W T
WT
Golde
W S
WS
Dynan
W
W
Wachsman
D001483:Base Sequence; D001665:Binding Sites; D022762:CCAAT-Enhancer-Binding Proteins; D002460:Cell Line; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000378:metabolism*; D003850:Deoxyribonuclease I; D015967:Gene Expression Regulation, Viral; D005814:Genes, Viral; D006367:HeLa Cells; D015368:Human T-lymphotropic virus 1 / Q000235:genetics*; D008969:Molecular Sequence Data; D051839:NFI Transcription Factors; D009687:Nuclear Proteins; D011401:Promoter Regions, Genetic / Q000235:genetics; D012091:Repetitive Sequences, Nucleic Acid; D016329:Sp1 Transcription Factor; D013601:T-Lymphocytes / Q000378:metabolism / Q000382:microbiology; D015534:Trans-Activators / Q000502:physiology*; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D014162:Transfection; D051840:Y-Box-Binding Protein 1
D022762:CCAAT-Enhancer-Binding Proteins; D004268:DNA-Binding Proteins; D051839:NFI Transcription Factors; D009687:Nuclear Proteins; D016329:Sp1 Transcription Factor; D015534:Trans-Activators; D014157:Transcription Factors; D051840:Y-Box-Binding Protein 1; C070856:YBX1 protein, human; D003850:Deoxyribonuclease I