Calcineurin potentiates activation of the granulocyte-macrophage colony- stimulating factor gene in T cells: Involvement of the conserved lymphokine element 0

A. Tsuboi, E. S. Masuda, Y. Naito, H. Tokumitsu, K. I. Arai, N. Arai

Research output: Contribution to journalArticle

34 Citations (Scopus)

Abstract

Granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin- 2 (IL-2) are produced by stimulation with phorbol-12-myristate acetate (PMA) and calcium ionophore (A23187) in human T cell leukemia Jurkat cells. The expression of GM-CSF and IL-2 is inhibited by immunosuppressive drugs such as cyclosporin A (CsA) and FK506. Earlier studies on the IL-2 gene expression showed that overexpression of calcineurin (CN), a Ca2+/calmodulin-dependent protein phosphatase, can stimulate transcription from the IL-2 promoter through the NF-AT-binding site. In this study, we obtained evidence that transfection of the cDNAs for CN A (catalytic) and CN B (regulatory) subunits also augments transcription from the GM-CSF promoter and recovers the transcription inhibited by CsA. The constitutively active type of the CN A subunit, which lacks the auto-inhibitory and calmodulin-binding domains, acts in synergy with PMA to activate transcription from the GM-CSF promoter. We also found that the active CN partially replaces calcium ionophore in synergy with PMA to induce expression of endogenous GM-CSF and IL-2. By multimerizing the regulatory elements of the GM-CSF promoter, we found that one of the target sites for the CN action is the conserved lymphokine element 0 (CLE0), located at positions between -54 and -40. Mobility shift assays showed that the CLE0 sequence has an AP1-binding site and is associated with an NF-AT- like factor, termed NF-CLE0 γ. NF-CLE0 γ binding is induced by PMA/A23187 and is inhibited by treatment with CsA. These results suggest that CN is involved in the coordinated induction of the GM-CSF and IL-2 genes and that the CLE0 sequence of the GM-CSF gene is a functional analogue of the NF-AT- binding site in the IL-2 promoter, which mediates signals downstream of T cell activation.

Original languageEnglish
Pages (from-to)119-128
Number of pages10
JournalMolecular Biology of the Cell
Volume5
Issue number1
DOIs
Publication statusPublished - Jan 1 1994
Externally publishedYes

ASJC Scopus subject areas

  • Molecular Biology
  • Cell Biology

Fingerprint Dive into the research topics of 'Calcineurin potentiates activation of the granulocyte-macrophage colony- stimulating factor gene in T cells: Involvement of the conserved lymphokine element 0'. Together they form a unique fingerprint.

  • Cite this