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Proceedings of the National Academy of Sciences of the United States of America logoLink to Proceedings of the National Academy of Sciences of the United States of America
. 1992 Jul 15;89(14):6247–6251. doi: 10.1073/pnas.89.14.6247

The LIM family transcription factor Isl-1 requires cAMP response element binding protein to promote somatostatin expression in pancreatic islet cells.

J Leonard 1, P Serup 1, G Gonzalez 1, T Edlund 1, M Montminy 1
PMCID: PMC49477  PMID: 1352885

Abstract

Many eukaryotic genes are regulated by cAMP through a conserved cAMP response element (CRE). Here we show that, in the pancreatic islet cell line Tu6, a well-characterized CRE in the somatostatin gene does not provide cAMP responsiveness but functions as an essential element for its basal activity. DNA-binding and functional analyses indicate that the cAMP-responsive factor CREB regulates somatostatin expression in these cells without requirement for phosphorylation at the protein kinase A-regulated Ser-133 phosphorylation site. In addition to the CRE site, cell-specific expression of the somatostatin gene requires a second promoter element, which binds the recently characterized LIM family protein Isl-1. Thus, Isl-1 and CREB appear to synergize on the somatostatin promoter to stimulate high-level expression in Tu6 cells. The ability of CREB to function in a phosphorylation-independent manner suggests a mechanism by which this protein can regulate gene transcription.

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Selected References

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  1. Bodner M., Castrillo J. L., Theill L. E., Deerinck T., Ellisman M., Karin M. The pituitary-specific transcription factor GHF-1 is a homeobox-containing protein. Cell. 1988 Nov 4;55(3):505–518. doi: 10.1016/0092-8674(88)90037-2. [DOI] [PubMed] [Google Scholar]
  2. Delegeane A. M., Ferland L. H., Mellon P. L. Tissue-specific enhancer of the human glycoprotein hormone alpha-subunit gene: dependence on cyclic AMP-inducible elements. Mol Cell Biol. 1987 Nov;7(11):3994–4002. doi: 10.1128/mcb.7.11.3994. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Dignam J. D., Lebovitz R. M., Roeder R. G. Accurate transcription initiation by RNA polymerase II in a soluble extract from isolated mammalian nuclei. Nucleic Acids Res. 1983 Mar 11;11(5):1475–1489. doi: 10.1093/nar/11.5.1475. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Freyd G., Kim S. K., Horvitz H. R. Novel cysteine-rich motif and homeodomain in the product of the Caenorhabditis elegans cell lineage gene lin-11. Nature. 1990 Apr 26;344(6269):876–879. doi: 10.1038/344876a0. [DOI] [PubMed] [Google Scholar]
  5. Gonzalez G. A., Menzel P., Leonard J., Fischer W. H., Montminy M. R. Characterization of motifs which are critical for activity of the cyclic AMP-responsive transcription factor CREB. Mol Cell Biol. 1991 Mar;11(3):1306–1312. doi: 10.1128/mcb.11.3.1306. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Gonzalez G. A., Montminy M. R. Cyclic AMP stimulates somatostatin gene transcription by phosphorylation of CREB at serine 133. Cell. 1989 Nov 17;59(4):675–680. doi: 10.1016/0092-8674(89)90013-5. [DOI] [PubMed] [Google Scholar]
  7. Gonzalez G. A., Yamamoto K. K., Fischer W. H., Karr D., Menzel P., Biggs W., 3rd, Vale W. W., Montminy M. R. A cluster of phosphorylation sites on the cyclic AMP-regulated nuclear factor CREB predicted by its sequence. Nature. 1989 Feb 23;337(6209):749–752. doi: 10.1038/337749a0. [DOI] [PubMed] [Google Scholar]
  8. Karlsson O., Thor S., Norberg T., Ohlsson H., Edlund T. Insulin gene enhancer binding protein Isl-1 is a member of a novel class of proteins containing both a homeo- and a Cys-His domain. Nature. 1990 Apr 26;344(6269):879–882. doi: 10.1038/344879a0. [DOI] [PubMed] [Google Scholar]
  9. Liu F., Green M. R. A specific member of the ATF transcription factor family can mediate transcription activation by the adenovirus E1a protein. Cell. 1990 Jun 29;61(7):1217–1224. doi: 10.1016/0092-8674(90)90686-9. [DOI] [PubMed] [Google Scholar]
  10. Madsen O. D., Larsson L. I., Rehfeld J. F., Schwartz T. W., Lernmark A., Labrecque A. D., Steiner D. F. Cloned cell lines from a transplantable islet cell tumor are heterogeneous and express cholecystokinin in addition to islet hormones. J Cell Biol. 1986 Nov;103(5):2025–2034. doi: 10.1083/jcb.103.5.2025. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Montminy M. R., Bilezikjian L. M. Binding of a nuclear protein to the cyclic-AMP response element of the somatostatin gene. Nature. 1987 Jul 9;328(6126):175–178. doi: 10.1038/328175a0. [DOI] [PubMed] [Google Scholar]
  12. Montminy M. R., Goodman R. H., Horovitch S. J., Habener J. F. Primary structure of the gene encoding rat preprosomatostatin. Proc Natl Acad Sci U S A. 1984 Jun;81(11):3337–3340. doi: 10.1073/pnas.81.11.3337. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Montminy M. R., Sevarino K. A., Wagner J. A., Mandel G., Goodman R. H. Identification of a cyclic-AMP-responsive element within the rat somatostatin gene. Proc Natl Acad Sci U S A. 1986 Sep;83(18):6682–6686. doi: 10.1073/pnas.83.18.6682. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Sadowski I., Ptashne M. A vector for expressing GAL4(1-147) fusions in mammalian cells. Nucleic Acids Res. 1989 Sep 25;17(18):7539–7539. doi: 10.1093/nar/17.18.7539. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Waterman M. L., Jones K. A. Purification of TCF-1 alpha, a T-cell-specific transcription factor that activates the T-cell receptor C alpha gene enhancer in a context-dependent manner. New Biol. 1990 Jul;2(7):621–636. [PubMed] [Google Scholar]
  16. Winoto A., Baltimore D. A novel, inducible and T cell-specific enhancer located at the 3' end of the T cell receptor alpha locus. EMBO J. 1989 Mar;8(3):729–733. doi: 10.1002/j.1460-2075.1989.tb03432.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Yamamoto K. K., Gonzalez G. A., Biggs W. H., 3rd, Montminy M. R. Phosphorylation-induced binding and transcriptional efficacy of nuclear factor CREB. Nature. 1988 Aug 11;334(6182):494–498. doi: 10.1038/334494a0. [DOI] [PubMed] [Google Scholar]
  18. Yamamoto K. K., Gonzalez G. A., Menzel P., Rivier J., Montminy M. R. Characterization of a bipartite activator domain in transcription factor CREB. Cell. 1990 Feb 23;60(4):611–617. doi: 10.1016/0092-8674(90)90664-z. [DOI] [PubMed] [Google Scholar]

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