Multiple mechanisms regulate c‐myc gene expression during normal T cell activation.
T Lindsten, CH June, CB Thompson - The EMBO journal, 1988 - embopress.org
T Lindsten, CH June, CB Thompson
The EMBO journal, 1988•embopress.orgQuiescent normal human T cells express low levels of steady‐state c‐myc mRNA as a result
of low constitutive promoter utilization, a block to transcriptional elongation within the gene,
and rapid degradation of c‐myc mRNA in the cytoplasm. Following the activation of the T cell
receptor (TCR)/CD3 complex, quiescent T cells are induced to express c‐myc mRNA. Two
intracellular pathways, one involving protein kinase C activation and the other mediated by
increased intracellular calcium concentration, are activated by TCR/CD3 receptor …
of low constitutive promoter utilization, a block to transcriptional elongation within the gene,
and rapid degradation of c‐myc mRNA in the cytoplasm. Following the activation of the T cell
receptor (TCR)/CD3 complex, quiescent T cells are induced to express c‐myc mRNA. Two
intracellular pathways, one involving protein kinase C activation and the other mediated by
increased intracellular calcium concentration, are activated by TCR/CD3 receptor …
Quiescent normal human T cells express low levels of steady‐state c‐myc mRNA as a result of low constitutive promoter utilization, a block to transcriptional elongation within the gene, and rapid degradation of c‐myc mRNA in the cytoplasm. Following the activation of the T cell receptor (TCR)/CD3 complex, quiescent T cells are induced to express c‐myc mRNA. Two intracellular pathways, one involving protein kinase C activation and the other mediated by increased intracellular calcium concentration, are activated by TCR/CD3 receptor stimulation. These two pathways, which can be activated by phorbol myristate acetate (PMA) and ionomycin respectively, appear to play complementary roles in the transcriptional induction of c‐myc gene expression by the antigen receptor complex. Ionomycin treatment of quiescent cells leads to enhanced c‐myc expression primarily as a result of increased transcriptional initiation. In contrast, PMA contributes to c‐myc expression, at least in part, by decreasing the block to transcriptional elongation present within the gene. Both the PMA‐ and ionomycin‐mediated induction of c‐myc expression can be independently enhanced by stabilization of c‐myc mRNA in the cytoplasm. These observations demonstrate that multiple mechanisms co‐operate to regulate c‐myc gene expression during normal T cell activation.
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