Abstract
Glucokinase, a key regulatory enzyme of glucose metabolism in mammals, provides an interesting model of tissue-specific gene expression. The single-copy gene is expressed principally in liver, where it gives rise to a 2.4-kilobase mRNA. The islets of Langerhans of the pancreas also contain glucokinase. Using a cDNA complementary to rat liver glucokinase mRNA, we show that normal pancreatic islets and tumoral islet cells contain a glucokinase mRNA species approximately 400 nucleotides longer than hepatic mRNA. Hybridization with synthetic oligonucleotides and primer-extension analysis show that the liver and islet glucokinase mRNAs differ in the 5' region. Glucokinase mRNA is absent from the livers of fasted rats and is strongly induced within hours by an oral glucose load. In contrast, islet glucokinase mRNA is expressed at a constant level during the fasting-refeeding cycle. The level of glucokinase protein in islets measured by immunoblotting is unaffected by fasting and refeeding, whereas a 3-fold increase in the amount of enzyme occurs in liver during the transition from fasting to refeeding. From these data, we conclude (i) that alternative splicing and/or the use of distinct tissue-specific promoters generate structurally distinct mRNA species in liver and islets of Langerhans and (ii) that tissue-specific transcription mechanisms result in inducible expression of the glucokinase gene in liver but not in islets during the fasting-refeeding transition.
Full text
PDFImages in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Andreone T. L., Printz R. L., Pilkis S. J., Magnuson M. A., Granner D. K. The amino acid sequence of rat liver glucokinase deduced from cloned cDNA. J Biol Chem. 1989 Jan 5;264(1):363–369. [PubMed] [Google Scholar]
- Bhathena S. J., Oie H. K., Gazdar A. F., Voyles N. R., Wilkins S. D., Recant L. Insulin, glucagon, and somatostatin receptors on cultured cells and clones from rat islet cell tumor. Diabetes. 1982 Jun;31(6 Pt 1):521–531. doi: 10.2337/diab.31.6.521. [DOI] [PubMed] [Google Scholar]
- Burch P. T., Trus M. D., Berner D. K., Leontire A., Zawalich K. C., Matschinsky F. M. Adaptation of glycolytic enzymes: glucose use and insulin release in rat pancreatic islets during fasting and refeeding. Diabetes. 1981 Nov;30(11):923–928. doi: 10.2337/diab.30.11.923. [DOI] [PubMed] [Google Scholar]
- Chan S. J., Noyes B. E., Agarwal K. L., Steiner D. F. Construction and selection of recombinant plasmids containing full-length complementary DNAs corresponding to rat insulins I and II. Proc Natl Acad Sci U S A. 1979 Oct;76(10):5036–5040. doi: 10.1073/pnas.76.10.5036. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 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]
- Feinberg A. P., Vogelstein B. "A technique for radiolabeling DNA restriction endonuclease fragments to high specific activity". Addendum. Anal Biochem. 1984 Feb;137(1):266–267. doi: 10.1016/0003-2697(84)90381-6. [DOI] [PubMed] [Google Scholar]
- Gazdar A. F., Chick W. L., Oie H. K., Sims H. L., King D. L., Weir G. C., Lauris V. Continuous, clonal, insulin- and somatostatin-secreting cell lines established from a transplantable rat islet cell tumor. Proc Natl Acad Sci U S A. 1980 Jun;77(6):3519–3523. doi: 10.1073/pnas.77.6.3519. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Grey N. J., Goldring S., Kipnis D. M. The effect of fasting, diet, and actinomycin D on insulin secretion in the rat. J Clin Invest. 1970 May;49(5):881–889. doi: 10.1172/JCI106307. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Iynedjian P. B., Gjinovci A., Renold A. E. Stimulation by insulin of glucokinase gene transcription in liver of diabetic rats. J Biol Chem. 1988 Jan 15;263(2):740–744. [PubMed] [Google Scholar]
- Iynedjian P. B., Möbius G., Seitz H. J., Wollheim C. B., Renold A. E. Tissue-specific expression of glucokinase: identification of the gene product in liver and pancreatic islets. Proc Natl Acad Sci U S A. 1986 Apr;83(7):1998–2001. doi: 10.1073/pnas.83.7.1998. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Iynedjian P. B., Ucla C., Mach B. Molecular cloning of glucokinase cDNA. Developmental and dietary regulation of glucokinase mRNA in rat liver. J Biol Chem. 1987 May 5;262(13):6032–6038. [PubMed] [Google Scholar]
- Leff S. E., Rosenfeld M. G., Evans R. M. Complex transcriptional units: diversity in gene expression by alternative RNA processing. Annu Rev Biochem. 1986;55:1091–1117. doi: 10.1146/annurev.bi.55.070186.005303. [DOI] [PubMed] [Google Scholar]
- López-Casillas F., Kim K. H. Heterogeneity at the 5' end of rat acetyl-coenzyme A carboxylase mRNA. Lipogenic conditions enhance synthesis of a unique mRNA in liver. J Biol Chem. 1989 May 5;264(13):7176–7184. [PubMed] [Google Scholar]
- Meglasson M. D., Burch P. T., Berner D. K., Najafi H., Vogin A. P., Matschinsky F. M. Chromatographic resolution and kinetic characterization of glucokinase from islets of Langerhans. Proc Natl Acad Sci U S A. 1983 Jan;80(1):85–89. doi: 10.1073/pnas.80.1.85. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Meglasson M. D., Matschinsky F. M. New perspectives on pancreatic islet glucokinase. Am J Physiol. 1984 Jan;246(1 Pt 1):E1–13. doi: 10.1152/ajpendo.1984.246.1.E1. [DOI] [PubMed] [Google Scholar]
- Meglasson M. D., Matschinsky F. M. Pancreatic islet glucose metabolism and regulation of insulin secretion. Diabetes Metab Rev. 1986;2(3-4):163–214. doi: 10.1002/dmr.5610020301. [DOI] [PubMed] [Google Scholar]
- Newgard C. B., Nakano K., Hwang P. K., Fletterick R. J. Sequence analysis of the cDNA encoding human liver glycogen phosphorylase reveals tissue-specific codon usage. Proc Natl Acad Sci U S A. 1986 Nov;83(21):8132–8136. doi: 10.1073/pnas.83.21.8132. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Philippe J., Chick W. L., Habener J. F. Multipotential phenotypic expression of genes encoding peptide hormones in rat insulinoma cell lines. J Clin Invest. 1987 Feb;79(2):351–358. doi: 10.1172/JCI112819. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pilkis S. J., el-Maghrabi M. R., Claus T. H. Hormonal regulation of hepatic gluconeogenesis and glycolysis. Annu Rev Biochem. 1988;57:755–783. doi: 10.1146/annurev.bi.57.070188.003543. [DOI] [PubMed] [Google Scholar]
- SALAS M., VINUELA E., SOLS A. INSULIN-DEPENDENT SYNTHESIS OF LIVER GLUCOKINASE IN THE RAT. J Biol Chem. 1963 Nov;238:3535–3538. [PubMed] [Google Scholar]
- SHARMA C., MANJESHWAR R., WEINHOUSE S. EFFECTS OF DIET AND INSULIN ON GLUCOSE-ADENOSINE TRIPHOSPHATE PHOSPHOTRANSFERASES OF RAT LIVER. J Biol Chem. 1963 Dec;238:3840–3845. [PubMed] [Google Scholar]
- STEINER D. F. MECHANISMS OF REGULATION OF HEPATIC GLYCOGEN SYNTHESIS. Nature. 1964 Dec 19;204:1171–1173. doi: 10.1038/2041171a0. [DOI] [PubMed] [Google Scholar]
- Savakis C., Ashburner M. A simple gene with a complex pattern of transcription: the alcohol dehydrogenase gene of Drosophila melanogaster. Cold Spring Harb Symp Quant Biol. 1985;50:505–514. doi: 10.1101/sqb.1985.050.01.062. [DOI] [PubMed] [Google Scholar]
- Schibler U., Sierra F. Alternative promoters in developmental gene expression. Annu Rev Genet. 1987;21:237–257. doi: 10.1146/annurev.ge.21.120187.001321. [DOI] [PubMed] [Google Scholar]
- Shimizu T., Knowles B. B., Matschinsky F. M. Control of glucose phosphorylation and glucose usage in clonal insulinoma cells. Diabetes. 1988 May;37(5):563–568. doi: 10.2337/diab.37.5.563. [DOI] [PubMed] [Google Scholar]
- Trus M. D., Zawalich W. S., Burch P. T., Berner D. K., Weill V. A., Matschinsky F. M. Regulation of glucose metabolism in pancreatic islets. Diabetes. 1981 Nov;30(11):911–922. doi: 10.2337/diab.30.11.911. [DOI] [PubMed] [Google Scholar]
- Vischer U., Blondel B., Wollheim C. B., Höppner W., Seitz H. J., Iynedjian P. B. Hexokinase isoenzymes of RIN-m5F insulinoma cells. Expression of glucokinase gene in insulin-producing cells. Biochem J. 1987 Jan 1;241(1):249–255. doi: 10.1042/bj2410249. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Weinhouse S. Regulation of glucokinase in liver. Curr Top Cell Regul. 1976;11:1–50. [PubMed] [Google Scholar]
- Young R. A., Hagenbüchle O., Schibler U. A single mouse alpha-amylase gene specifies two different tissue-specific mRNAs. Cell. 1981 Feb;23(2):451–458. doi: 10.1016/0092-8674(81)90140-9. [DOI] [PubMed] [Google Scholar]