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. 1996 Jan;16(1):19–28. doi: 10.1128/mcb.16.1.19

Activation of proglucagon gene transcription through a novel promoter element by the caudal-related homeodomain protein cdx-2/3.

T Jin 1, D J Drucker 1
PMCID: PMC230974  PMID: 8524295

Abstract

The proglucagon gene is expressed in a highly restricted tissue-specific manner in the A cells of the pancreatic islet and the L cells of the small and large intestines. The results of previous experiments indicate that cell-specific expression of the proglucagon gene is mediated by proteins that interact with the proximal G1 promoter element. We show here that the G1 element contains several AT-rich subdomains that bind proteins present in islet and enteroendocrine cell extracts. Electrophoretic mobility shift assay experiments using specific antisera identified the homeobox protein cdx-2/3 (which designates the same homeobox protein called cdx-2 for mice and cdx-3 for hamsters) as a major component of the G1-Gc2 complex in islet and intestinal cells. Mutations of the Gc element that decreased cdx-2/3 binding also resulted in decreased proglucagon promoter activity in islet and intestinal cell lines. The finding that cdx-2/3 mediates activation of the proglucagon promoter in both islet and enteroendocrine cells is consistent with the common endodermal lineage of these tissues and provides new insight into the coordinate regulation of genes expressed in both pancreatic and intestinal endocrine cell types.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Bell G. I., Santerre R. F., Mullenbach G. T. Hamster preproglucagon contains the sequence of glucagon and two related peptides. Nature. 1983 Apr 21;302(5910):716–718. doi: 10.1038/302716a0. [DOI] [PubMed] [Google Scholar]
  2. Chomczynski P., Sacchi N. Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction. Anal Biochem. 1987 Apr;162(1):156–159. doi: 10.1006/abio.1987.9999. [DOI] [PubMed] [Google Scholar]
  3. Dearolf C. R., Topol J., Parker C. S. The caudal gene product is a direct activator of fushi tarazu transcription during Drosophila embryogenesis. Nature. 1989 Sep 28;341(6240):340–343. doi: 10.1038/341340a0. [DOI] [PubMed] [Google Scholar]
  4. Drucker D. J., Asa S. Glucagon gene expression in vertebrate brain. J Biol Chem. 1988 Sep 25;263(27):13475–13478. [PubMed] [Google Scholar]
  5. Drucker D. J., Brubaker P. L. Proglucagon gene expression is regulated by a cyclic AMP-dependent pathway in rat intestine. Proc Natl Acad Sci U S A. 1989 Jun;86(11):3953–3957. doi: 10.1073/pnas.86.11.3953. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Drucker D. J., Jin T., Asa S. L., Young T. A., Brubaker P. L. Activation of proglucagon gene transcription by protein kinase-A in a novel mouse enteroendocrine cell line. Mol Endocrinol. 1994 Dec;8(12):1646–1655. doi: 10.1210/mend.8.12.7535893. [DOI] [PubMed] [Google Scholar]
  7. Drucker D. J., Philippe J., Jepeal L., Habener J. F. Glucagon gene 5'-flanking sequences promote islet cell-specific gene transcription. J Biol Chem. 1987 Nov 15;262(32):15659–15665. [PubMed] [Google Scholar]
  8. Drucker D. J., Philippe J., Mojsov S. Proglucagon gene expression and posttranslational processing in a hamster islet cell line. Endocrinology. 1988 Oct;123(4):1861–1867. doi: 10.1210/endo-123-4-1861. [DOI] [PubMed] [Google Scholar]
  9. Galang C. K., Hauser C. A. Cooperative DNA binding of the human HoxB5 (Hox-2.1) protein is under redox regulation in vitro. Mol Cell Biol. 1993 Aug;13(8):4609–4617. doi: 10.1128/mcb.13.8.4609. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. German M. S., Wang J., Chadwick R. B., Rutter W. J. Synergistic activation of the insulin gene by a LIM-homeo domain protein and a basic helix-loop-helix protein: building a functional insulin minienhancer complex. Genes Dev. 1992 Nov;6(11):2165–2176. doi: 10.1101/gad.6.11.2165. [DOI] [PubMed] [Google Scholar]
  11. Hu Y., Kazenwadel J., James R. Isolation and characterization of the murine homeobox gene Cdx-1. Regulation of expression in intestinal epithelial cells. J Biol Chem. 1993 Dec 25;268(36):27214–27225. [PubMed] [Google Scholar]
  12. James R., Erler T., Kazenwadel J. Structure of the murine homeobox gene cdx-2. Expression in embryonic and adult intestinal epithelium. J Biol Chem. 1994 May 27;269(21):15229–15237. [PubMed] [Google Scholar]
  13. James R., Kazenwadel J. Homeobox gene expression in the intestinal epithelium of adult mice. J Biol Chem. 1991 Feb 15;266(5):3246–3251. [PubMed] [Google Scholar]
  14. Knepel W., Jepeal L., Habener J. F. A pancreatic islet cell-specific enhancer-like element in the glucagon gene contains two domains binding distinct cellular proteins. J Biol Chem. 1990 May 25;265(15):8725–8735. [PubMed] [Google Scholar]
  15. Knepel W., Vallejo M., Chafitz J. A., Habener J. F. The pancreatic islet-specific glucagon G3 transcription factors recognize control elements in the rat somatostatin and insulin-I genes. Mol Endocrinol. 1991 Oct;5(10):1457–1466. doi: 10.1210/mend-5-10-1457. [DOI] [PubMed] [Google Scholar]
  16. Lee Y. C., Asa S. L., Drucker D. J. Glucagon gene 5'-flanking sequences direct expression of simian virus 40 large T antigen to the intestine, producing carcinoma of the large bowel in transgenic mice. J Biol Chem. 1992 May 25;267(15):10705–10708. [PubMed] [Google Scholar]
  17. Leonard J., Peers B., Johnson T., Ferreri K., Lee S., Montminy M. R. Characterization of somatostatin transactivating factor-1, a novel homeobox factor that stimulates somatostatin expression in pancreatic islet cells. Mol Endocrinol. 1993 Oct;7(10):1275–1283. doi: 10.1210/mend.7.10.7505393. [DOI] [PubMed] [Google Scholar]
  18. Margalit Y., Yarus S., Shapira E., Gruenbaum Y., Fainsod A. Isolation and characterization of target sequences of the chicken CdxA homeobox gene. Nucleic Acids Res. 1993 Oct 25;21(21):4915–4922. doi: 10.1093/nar/21.21.4915. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Miller C. P., McGehee R. E., Jr, Habener J. F. IDX-1: a new homeodomain transcription factor expressed in rat pancreatic islets and duodenum that transactivates the somatostatin gene. EMBO J. 1994 Mar 1;13(5):1145–1156. doi: 10.1002/j.1460-2075.1994.tb06363.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Mlodzik M., Fjose A., Gehring W. J. Isolation of caudal, a Drosophila homeo box-containing gene with maternal expression, whose transcripts form a concentration gradient at the pre-blastoderm stage. EMBO J. 1985 Nov;4(11):2961–2969. doi: 10.1002/j.1460-2075.1985.tb04030.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Mlodzik M., Gehring W. J. Expression of the caudal gene in the germ line of Drosophila: formation of an RNA and protein gradient during early embryogenesis. Cell. 1987 Feb 13;48(3):465–478. doi: 10.1016/0092-8674(87)90197-8. [DOI] [PubMed] [Google Scholar]
  22. Mojsov S., Heinrich G., Wilson I. B., Ravazzola M., Orci L., Habener J. F. Preproglucagon gene expression in pancreas and intestine diversifies at the level of post-translational processing. J Biol Chem. 1986 Sep 5;261(25):11880–11889. [PubMed] [Google Scholar]
  23. Morel C., Cordier-Bussat M., Philippe J. The upstream promoter element of the glucagon gene, G1, confers pancreatic alpha cell-specific expression. J Biol Chem. 1995 Feb 17;270(7):3046–3055. doi: 10.1074/jbc.270.7.3046. [DOI] [PubMed] [Google Scholar]
  24. Orskov C., Holst J. J., Poulsen S. S., Kirkegaard P. Pancreatic and intestinal processing of proglucagon in man. Diabetologia. 1987 Nov;30(11):874–881. doi: 10.1007/BF00274797. [DOI] [PubMed] [Google Scholar]
  25. Peers B., Leonard J., Sharma S., Teitelman G., Montminy M. R. Insulin expression in pancreatic islet cells relies on cooperative interactions between the helix loop helix factor E47 and the homeobox factor STF-1. Mol Endocrinol. 1994 Dec;8(12):1798–1806. doi: 10.1210/mend.8.12.7708065. [DOI] [PubMed] [Google Scholar]
  26. Philippe J., Drucker D. J., Knepel W., Jepeal L., Misulovin Z., Habener J. F. Alpha-cell-specific expression of the glucagon gene is conferred to the glucagon promoter element by the interactions of DNA-binding proteins. Mol Cell Biol. 1988 Nov;8(11):4877–4888. doi: 10.1128/mcb.8.11.4877. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Philippe J., Mojsov S., Drucker D. J., Habener J. F. Proglucagon processing in a rat islet cell line resembles phenotype of intestine rather than pancreas. Endocrinology. 1986 Dec;119(6):2833–2839. doi: 10.1210/endo-119-6-2833. [DOI] [PubMed] [Google Scholar]
  28. Philippe J., Morel C., Cordier-Bussat M. Islet-specific proteins interact with the insulin-response element of the glucagon gene. J Biol Chem. 1995 Feb 17;270(7):3039–3045. doi: 10.1074/jbc.270.7.3039. [DOI] [PubMed] [Google Scholar]
  29. Philippe J., Morel C., Prezioso V. R. Glucagon gene expression is negatively regulated by hepatocyte nuclear factor 3 beta. Mol Cell Biol. 1994 May;14(5):3514–3523. doi: 10.1128/mcb.14.5.3514. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Powers A. C., Tedeschi F., Wright K. E., Chan J. S., Habener J. F. Somatostatin gene expression in pancreatic islet cells is directed by cell-specific DNA control elements and DNA-binding proteins. J Biol Chem. 1989 Jun 15;264(17):10048–10056. [PubMed] [Google Scholar]
  31. Rindi G., Grant S. G., Yiangou Y., Ghatei M. A., Bloom S. R., Bautch V. L., Solcia E., Polak J. M. Development of neuroendocrine tumors in the gastrointestinal tract of transgenic mice. Heterogeneity of hormone expression. Am J Pathol. 1990 Jun;136(6):1349–1363. [PMC free article] [PubMed] [Google Scholar]
  32. Rudnick A., Ling T. Y., Odagiri H., Rutter W. J., German M. S. Pancreatic beta cells express a diverse set of homeobox genes. Proc Natl Acad Sci U S A. 1994 Dec 6;91(25):12203–12207. doi: 10.1073/pnas.91.25.12203. [DOI] [PMC free article] [PubMed] [Google Scholar]
  33. Schreiber E., Matthias P., Müller M. M., Schaffner W. Rapid detection of octamer binding proteins with 'mini-extracts', prepared from a small number of cells. Nucleic Acids Res. 1989 Aug 11;17(15):6419–6419. doi: 10.1093/nar/17.15.6419. [DOI] [PMC free article] [PubMed] [Google Scholar]
  34. Suh E., Chen L., Taylor J., Traber P. G. A homeodomain protein related to caudal regulates intestine-specific gene transcription. Mol Cell Biol. 1994 Nov;14(11):7340–7351. doi: 10.1128/mcb.14.11.7340. [DOI] [PMC free article] [PubMed] [Google Scholar]
  35. Sánchez-García I., Rabbitts T. H. Redox regulation of in vitro DNA-binding activity by the homeodomain of the Isl-1 protein. J Mol Biol. 1993 Jun 20;231(4):945–949. doi: 10.1006/jmbi.1993.1343. [DOI] [PubMed] [Google Scholar]

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