A 36-kilodalton cellular transcription factor mediates an indirect interaction of human T-cell leukemia/lymphoma virus type I TAX1 with a responsive element in the viral long terminal repeat.
The human T-cell leukemia/lymphoma virus type I (HTLV-I) trans activator, TAX1, interacts indirectly with a TAX1-responsive element, TRE-2, located at positions -117 to -163 in the viral long terminal repeat. This report describes the characterization of a 36-kilodalton (kDa) protein identified in HeLa nuclear extract which mediates the interaction of TAX1 with TRE-2. Purification of the protein was achieved by zinc chelate chromatography and preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The renatured 36-kDa protein bound specifically to a TRE-2 oligonucleotide but not to nonfunctional base substitution mutant probes in a gel retardation assay. Renatured proteins of differing molecular weights were unable to form this complex. In addition, the 36-kDa protein specifically activated transcription from the HTLV-I promoter in vitro. Purified TAX1 protein formed a complex with the TRE-2 oligonucleotide in the presence of the 36-kDa protein, suggesting that indirect interaction of TAX1 with the viral long terminal repeat may be one of the mechanisms by which HTLV-I transcription is regulated.
Marriott
S J
SJ
Laboratory of Molecular Virology, National Cancer Institute, Bethesda, Maryland 20892.
Lindholm
P F
PF
Brown
K M
KM
Gitlin
S D
SD
Duvall
J F
JF
Radonovich
M F
MF
Brady
J N
JN
D002467:Cell Nucleus / Q000378:metabolism; D002850:Chromatography, Gel; D004279:DNA, Viral / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells / Q000378:metabolism; D015368:Human T-lymphotropic virus 1 / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D015345:Oligonucleotide Probes; D011485:Protein Binding; D012091:Repetitive Sequences, Nucleic Acid; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors / Q000302:isolation & purification / Q000378:metabolism*; D014158:Transcription, Genetic
D004279:DNA, Viral; D015345:Oligonucleotide Probes; D015534:Trans-Activators; D014157:Transcription Factors