TPA activates p21WAF-1 promoter in human T-cells through its second most upstream Sp1 site

Y. Schavinsky-Khrapunsky, M. Huleihel, M. Aboud, A. Torgeman

Research output: Contribution to journalArticlepeer-review

6 Scopus citations


The p21WAF-1 promoter contains binding sites for a number of transcription factors which mediate its activation by a variety of external signals. Moreover, it has been reported that the transcription factors involved in p21WAF-1 activation by certain signaling factors, like the phorbol ester TPA, may vary in different cell types. We were interested in elucidating the mechanism of p21WAF-1 activation by TPA in human T-cells, since this activation could explain the antagonistic effect of PKC on apoptosis induction in these cells noted in our previous studies. Using the Jurkat human T-cells we found that TPA activated p21WAF-1 expression by a PKC-dependent mechanism and that out of six Sp1 binding sites residing in its promoter the second most upstream one was critically essential for this activation. Since p21WAF-1 is known to inhibit the onset of apoptosis, its PKC-dependent activation may likely account for the PKC antagonistic effect on apoptosis induction in these cells.

Original languageEnglish
Pages (from-to)696-700
Number of pages5
JournalBiochemical and Biophysical Research Communications
Issue number4
StatePublished - 16 May 2003


  • CDK
  • CDK-inhibitors
  • Cell-cycle
  • Human T-cells
  • Jurkat cells
  • PKC
  • Sp1
  • TPA
  • Transcription factors
  • p21

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology


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