Identification of a Glucose Response Element in the Promoter of the Rat Glucagon Receptor Gene

• Published in: The Journal of biological chemistry Vol. 274; no. 12; pp. 8181 - 8190
• Main Authors: Portois, L, Maget, B, Tastenoy, M, Perret, J, Svoboda, M
• Format: Journal Article
• Language: English
• Published: United States American Society for Biochemistry and Molecular Biology 19-03-1999
• Subjects: Animals; Base Sequence; Blotting, Southern; DNA - metabolism; DNA Primers - metabolism; Gene Library; Glucose - metabolism; Molecular Sequence Data; Promoter Regions, Genetic; Random Amplified Polymorphic DNA Technique; Rats; Receptors, Glucagon - genetics; Transfection
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.274.12.8181

We cloned the 5′ upstream region of the rat glucagon receptor gene, demonstrating that the 5′ noncoding domain of the glucagon
receptor mRNA contained two untranslated exons of 131 and 166 nucleotides (nt), respectively, separated by two introns of
0.6 and 3.2 kilobase pairs. We also observed an alternative splicing involving the 166-base pair exon. Cloning of up to 2
kilobase pairs of the newly identified genomic domain and transfection of various constructs driving a reporter gene, in pancreatic
islet cell line INS-1, uncovered a strong glucose regulation of the promoter activity of plasmids containing up to nucleotide
−868, or more, upstream from the transcriptional start point. This promoter activity displayed threshold-like behavior, with
low activity of the promoter below 5 m m glucose, and maximal activation as of 10 m m glucose. This glucose regulation was mapped to a highly palindromic 19-nucleotide region between nt −545 and −527. Indeed,
deletion or mutation of this sequence abolished the glucose regulation. This domain contained two palindromic “E-boxes” CACGTG
and CAGCTG separated by 3 nt, a feature similar to the “L4 box” found in the pyruvate kinase L gene promoter. This is the
first description of a G protein-coupled receptor gene promoter regulated by glucose.