Role of a STAT binding site in the regulation of the human perforin promoter

CR Yu, JR Ortaldo, RE Curiel, HA Young… - The Journal of …, 1999 - journals.aai.org
CR Yu, JR Ortaldo, RE Curiel, HA Young, SK Anderson, P Gosselin
The Journal of Immunology, 1999journals.aai.org
The pore-forming protein perforin is preferentially expressed in NK and cytotoxic T cells. To
investigate the molecular regulation of human perforin gene transcription, the activity of the
human perforin promoter was analyzed in human NK and T cell lines using various promoter
fragments linked to a luciferase reporter gene. A core promoter was identified within 55 bp
upstream of the transcription start site. This promoter region contains a guanine/cytosine box
and has basal activity in YT, Kit225-k6, and Jurkat cells. A strong enhancer activity was …
Abstract
The pore-forming protein perforin is preferentially expressed in NK and cytotoxic T cells. To investigate the molecular regulation of human perforin gene transcription, the activity of the human perforin promoter was analyzed in human NK and T cell lines using various promoter fragments linked to a luciferase reporter gene. A core promoter was identified within 55 bp upstream of the transcription start site. This promoter region contains a guanine/cytosine box and has basal activity in YT, Kit225-k6, and Jurkat cells. A strong enhancer activity was identified between positions− 1136 and− 1076, a region that includes a STAT-like element. This enhancer region was active in YT cells, which have constitutive perforin expression and activated STAT3 protein, but not in Kit225-k6 or Jurkat cells, which do not have constitutive perforin expression. Mutation of the STAT binding site resulted in a dramatic down-regulation of promoter activity. Electrophoretic mobility shift assays, using a probe containing the STAT element of the perforin promoter, indicated that this element can bind STAT3 from YT cells. Moreover, the STAT element was shown to bind STAT5a/b induced by IL-2 as well as STAT1α induced by IL-6 in human NK cells. Together, these results suggest that STAT proteins play a key role in perforin gene transcription and provide a model by which cytokines can regulate perforin gene expression.
journals.aai.org