Interaction of cellular proteins with the human T-cell leukemia virus type I transcriptional control region. Purification of cellular proteins that bind the 21-base pair repeat elements.
Nuclear extracts of cultured human cells contain multiple proteins that recognize specific sequence elements within the transcriptional control region of the human retrovirus, human T-cell leukemia virus type I (HTLV-I). Here we report the purification of host expression factor 1T (HEF-1T), a DNA-binding protein from human T-lymphocytes that binds to each of the three 21-base pair repeat enhancer elements in the proviral long terminal repeats of HTLV-I and the related virus, HTLV-II. HEF-1T is composed of two polypeptides of 41 and 59 kDa. We show that HEF-1T is distinct from a second protein, present in non-lymphoid cells, that binds to overlapping sites in and near the 21-base pair repeats. This second protein is composed of a single 47-kDa polypeptide and appears to be identical to the previously described transcription factor AP-2. A third protein, also distinct from HEF-1T, binds within the first repeat. The present results suggest that there may be multiple modes of HTLV-I promoter recognition involving distinct sets of cellular proteins.
Nyborg
J K
JK
Department of Chemistry and Biochemistry, University of Colorado, Boulder 80309.
Dynan
W S
WS
D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D002846:Chromatography, Affinity; D004268:DNA-Binding Proteins / Q000302:isolation & purification* / Q000378:metabolism; D003850:Deoxyribonuclease I; D004591:Electrophoresis, Polyacrylamide Gel; D005814:Genes, Viral; D006367:HeLa Cells; D015368:Human T-lymphotropic virus 1 / Q000235:genetics*; D015367:Human T-lymphotropic virus 2 / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D012091:Repetitive Sequences, Nucleic Acid; D013601:T-Lymphocytes / Q000032:analysis* / Q000382:microbiology; D014158:Transcription, Genetic
D004268:DNA-Binding Proteins; D015345:Oligonucleotide Probes; D003850:Deoxyribonuclease I