Isolation of cDNAs for DNA-binding proteins which specifically bind to tax-responsive enhancer element in the long terminal repeat of human T-cell leukemia virus type I

A. Tsujimoto, H. Nyunoya, T. Morita, T. Sato, K. Shimotohno

Research output: Contribution to journalArticle

91 Citations (Scopus)


One of the gene products of human T-cell leukemia virus type I (HTLV-I), p40(tax), activates its own viral transcription in trans through tax-responsive enhancers in viral long terminal repeats. Five species of cDNA clones for proteins that bind to the tax-responsive enhancer element in HTLV-1 were isolated from the Jurkat cell library. The β-galactosidase fusion protein prepared from the lysogen of a clone specifically recognized the cyclic AMP-responsive element in HTLV-I enhancer. The nucleotide sequence of a full-length cDNA clone (TAXREB67) had a coding capacity of 351 amino acids, which contained a basic motif followed by a leucine zipper structure near the carboxy terminus. Its mRNA was detected in human cell lines, including HTLV-1-infected or noninfected hematopoietic cell lines. The mRNA level in Jurkat cells was decreased temporarily by increasing cyclic AMP concentration hut increased by increasing Ca2+ concentration. Polyclonal antibodies against the fusion protein specifically recognized a 52-kDa protein in Jurkat cells. Analyses of the function of this protein and its interactions with other cellular factors will be useful to help understand the regulatory mechanism through tax-responsive enhancers in HTLV-I.

Original languageEnglish
Pages (from-to)1420-1426
Number of pages7
JournalJournal of Virology
Issue number3
Publication statusPublished - 1991 Jan 1


ASJC Scopus subject areas

  • Microbiology
  • Immunology
  • Insect Science
  • Virology

Cite this