Strong trans activation of the human cytomegalovirus major immediate-early enhancer by p40tax of human T-cell leukemia virus type I via two repetitive tax-responsive sequence elements.
The immediate-early 1 and 2 gene locus of human cytomegalovirus (HCMV) that encodes trans-activator proteins with effects on both homologous and heterologous promoters is expressed under control of a complex enhancer/promoter regulatory region. This enhancer contains four types of repetitive sequence elements with 17, 18, 19, and 21 bp that bind cellular transcription factors. Although the HCMV enhancer acts as a powerful stimulator of transcription in most cell types examined, human T cells do not support strong activity. The present study demonstrates that the tax gene product of human T-cell leukemia virus type I trans activates the major enhancer of HCMV more than 60-fold in the T-cell line Jurkat. When a series of chloramphenicol acetyltransferase expression plasmids containing synthetic oligonucleotides with the 17-, 18-, 19-, or 21-bp motif upstream of a minimal immediate-early 1 and 2 gene promoter was tested, two of the four repeat motifs could be identified as Tax-responsive elements. Both the 18- and the 19-bp motifs were able to act as strong Tax-responsive elements even when they were present as single copies. Thus, in addition to interacting with human immunodeficiency virus, HCMV is able to interact with a second retrovirus of clinical importance.
Moch
H
H
Institut für Klinische und Molekulare Virologie, Universität Erlangen-Nürnberg, Germany.
Lang
D
D
Stamminger
T
T
D001358:Avian Sarcoma Viruses / Q000235:genetics; D001483:Base Sequence; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D003587:Cytomegalovirus / Q000235:genetics*; D004742:Enhancer Elements, Genetic; D015967:Gene Expression Regulation, Viral; D016356:Gene Products, tax / Q000235:genetics / Q000378:metabolism*; D016355:Genes, pX; D015368:Human T-lymphotropic virus 1 / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D010957:Plasmids; D012367:RNA, Viral / Q000235:genetics / Q000302:isolation & purification; D012091:Repetitive Sequences, Nucleic Acid; D013601:T-Lymphocytes; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014162:Transfection; D014407:Tumor Cells, Cultured
D016356:Gene Products, tax; D012367:RNA, Viral; D015500:Chloramphenicol O-Acetyltransferase