Reconstitution of the functional granulocyte macrophage colony stimulating factor promoter: evidence for distinct activation mechanisms that mediate the response to phorbol ester/calcium and human T cell leukemia virus type I Tax signals.
Functional elements in the promoter region of the mouse granulocyte-macrophage colony stimulating factor (GM-CSF) gene were assessed by constructing chimeric promoters linked to the bacterial chloramphenicol acetyltransferase (CAT) gene and by employing a transient transfection assay of human T cell leukemia Jurkat cells. We previously reported that CLE2/GC-box (at positions -95 to -73, which is homologous to the NF-kappa B binding site) and CLE0 (at positions to -40) of the mouse GM-CSF promoter are essential for transcriptional activation in response to phorbol-12-myristate-13-acetate (PMA)/calcium ionophore (A23187). Here we show that CLE2/GC-box and the NF-kappa B binding motif are functionally interchangeable and that CLE2/GC-box and CLE0 as a unit activate the basic GM-CSF promoter in response to PMA/calcium signals. This unit is also capable of activating heterologous promoters in response to PMA/calcium signals. In addition, we show that Tax, the trans-activator encoded by human T cell leukemia virus type I (HTLV-I), activates the GM-CSF promoter via CLE2/GC-box without the involvement of CLE0. These results indicate that PMA/A23187-dependent and Tax-dependent activation of the GM-CSF gene proceeds through distinct mechanisms.
Department of Molecular and Developmental Biology, University of Tokyo, Japan.
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N
Koyano-Nakagawa
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Nishida
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Arai
K
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Arai
T
T
Yokota
D001483:Base Sequence; D000001:Calcimycin / Q000494:pharmacology; D002460:Cell Line; D004247:DNA / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects; D016355:Genes, pX; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000235:genetics*; D015368:Human T-lymphotropic virus 1 / Q000235:genetics; D006801:Humans; D007377:Interleukin-3 / Q000235:genetics; D015848:Interleukin-5 / Q000235:genetics; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic / Q000187:drug effects; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D007377:Interleukin-3; D015848:Interleukin-5; D000001:Calcimycin; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D004247:DNA; D013755:Tetradecanoylphorbol Acetate