Cell-type-specific transactivation of the parathyroid hormone-related protein gene promoter by the human T-cell leukemia virus type I (HTLV-I) Tax and HTLV-II Tax proteins

E. Ejima, J. D. Rosenblatt, M. Massari, E. Quan, D. Stephens, C. A. Rosen, D. Prager

Research output: Contribution to journalArticle

36 Scopus citations


The human T-cell leukemia virus type I (HTLV-I) and HTLV-II Tax proteins are potent transactivators of viral and cellular gene expression. Using deletion mutants, the downstream parathyroid hormone-related protein (PTHrP) promoter is shown to be responsive to both HTLV-I and HTLV-II Tax as well as the AP1/c-jun proto-oncogene. Transactivation of PTHrP by Tax was seen in T cells but not in B-cell lines or fibroblasts. A carboxy terminal Tax deletion mutant was deficient in transactivation of both the PTHrP and IL2Rα promoters but not the HTLV-I long terminal repeat (LTR). Exogenous provision of NFkB rescued IL2Rα expression but not the PTHrP promoter. Thus, HTLV-I Tax, HTLV-II Tax, and c-jun transactivate PTHrP and may contribute to the pathogenesis of hypercalcemia in adult T-cell leukemia.

Original languageEnglish (US)
Pages (from-to)1017-1024
Number of pages8
Issue number4
StatePublished - Jan 1 1993
Externally publishedYes


ASJC Scopus subject areas

  • Biochemistry
  • Immunology
  • Hematology
  • Cell Biology

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