High levels of AP-2-binding activity in cell lines infected with human T-cell leukemia virus type I: possible enhancement of AP-2 binding by human T-cell leukemia virus type I tax.
Human T-cell leukemia virus type I (HTLV-I) is the etiological agent for adult T-cell leukemia and tropical spastic paraparesis/HTLV-I-associated myelopathy. Recently, the transcription factor AP-2 has been demonstrated to be capable of activating gene expression from HTLV-I long terminal repeat. To determine whether changes occur in the levels of AP-2-binding activity in HTLV-I-infected cell lines, we compared the levels of AP-2 binding of nuclear extracts obtained from HTLV-I-infected T-cell lines with those of nuclear extracts obtained from uninfected T-cell lines. High levels of AP-2-binding activity were observed in HTLV-I-infected cell lines (MT-2, HUT-102, and SLB-1) using the mobility shift assay. In contrast, in the uninfected cell lines (Jurkat, HUT-78, and MLA 144), AP-2-binding activity was obviously low compared with that in the HTLV-I-infected cell lines. HTLV-I transactivator protein tax activates expression of both viral and cellular genes. We have demonstrated further that introduction of the tax gene into Jurkat cells stimulated AP-2-binding activity. These results indicate that HTLV-I-infected T cells exhibit constitutive AP-2-binding activity, and that tax may increase the DNA binding activity of AP-2.
Mori
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Department of Medicine, Cedars-Sinai Medical Center, University of California-Los Angeles School of Medicine 90048, USA.
Prager
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D
D000328:Adult; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D016355:Genes, pX; D015368:Human T-lymphotropic virus 1 / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D015459:Leukemia-Lymphoma, Adult T-Cell / Q000821:virology; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D015493:Paraparesis, Tropical Spastic / Q000821:virology; D011485:Protein Binding; D050656:Transcription Factor AP-2; D014157:Transcription Factors / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D004268:DNA-Binding Proteins; D015345:Oligonucleotide Probes; D050656:Transcription Factor AP-2; D014157:Transcription Factors