Isolation and Structural-Analysis of the 5′ Flanking Region of the Gene Encoding the Human Glucagon Receptor

Buggy, Joseph J.; Hull, J D; Yoo-Warren, Heeja

doi:10.1006/bbrc.1995.1343

Cited by 17 publications

(13 citation statements)

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“…Conflicting data have been published for the 5Ј end of glucagon receptor gene: Buggy et al reported the sequence of a putative human glucagon receptor promoter, separated from the initiation codon by an undescribed 5-kb intron (28). In contrast, Burcelin et al (17) reported the sequence of a putative mouse glucagon receptor promoter adjacent to the initiation codon.…”

Section: Fig 5 Cat Activity Of Ins-1 Cell Extracts Transfected Withmentioning

confidence: 76%

“…The size of the human 5Ј untranslated domain, estimated by primer extension assay, was larger (475 nt) than in rat (376 nt). The complete 5Ј sequence of human gene has not yet been reported (28), but comparison of the rat and the human glucagon receptor cDNAs shows a high (82%) homology in the coding domain (29,30).…”

Section: Fig 5 Cat Activity Of Ins-1 Cell Extracts Transfected Withmentioning

confidence: 99%

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

Portois

Maget

Tastenoy

et al. 1999

Journal of Biological Chemistry

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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 mM glucose, and maximal activation as of 10 mM 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.The primary physiological role of glucagon, together with insulin, is maintenance of normal glycemia. The liver has a central role in handling absorbed nutrients and in the regulation of hepatic glycogen disposability; this requires high density of glucagon receptors in the liver (for review see Refs. 1 and 2). The glucagon receptor mRNA has also been detected at variable levels in other tissues such as heart, kidney, adrenal gland, and adipose tissue (3-5), as well as in pancreatic islets, especially in B cells (6, 7). The expression of the glucagon receptor mRNA is stimulated by glucose and inhibited by cyclic AMP, both in liver (8) and in cultured endocrine cells (9). Consequently, the promoter of the glucagon receptor gene could contain regulatory elements for these factors. It has been recently suggested by Burcelin et al. (10) that the glucose regulation of the glucagon receptor mRNA level differs from the glucose regulation of other genes such as Glut2, and might be mediated by triose metabolites, suggesting the existence of new enhancer sequences. To address this question, a prerequisite is the precise knowledge of the complete 5Ј mRNA sequence. For the glucagon receptor mRNA, there was an ambiguity; the glucagon receptor cDNA has been first cloned (from rat) simultaneously by us (11, 12) and by Jelinek et al. (13). Our sequence (GenBank accession number L04796) was almost identical to that of Jelinek (GenBank accession number M96674) except for the 5Ј end; the first 25 nt 1 in our sequence (corresponding to positions Ϫ105 to Ϫ80 from the ATG codon) differed from the sequence published by Jelinek (13). The coding domain of the rat glucagon receptor gene is highly fragmented; it contains 12 introns with uneven splicing maturation (14) t...

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Section: Fig 5 Cat Activity Of Ins-1 Cell Extracts Transfected Withmentioning

confidence: 76%

Section: Fig 5 Cat Activity Of Ins-1 Cell Extracts Transfected Withmentioning

confidence: 99%

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

Portois

Maget

Tastenoy

et al. 1999

Journal of Biological Chemistry

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“…The 5Ј-flanking sequences of other closely related G proteincoupled receptors, such as GLP-1, glucagon, VIP, PACAP, PTH, and PTHRH, also contain GC-rich regions and possess multiple Sp1 motifs, suggesting evolutionary conservation of not only the structural gene but also the regulatory portion of the gene (1,2,7,27,34,42). When the regulatory regions of these other G protein-coupled receptor genes were analyzed, they were shown to bind the transcription factors Sp1 and the two isoforms of Sp3.…”

Section: Discussionmentioning

confidence: 99%

Sp1/Sp3 binding is associated with cell-specific expression of the glucose-dependent insulinotropic polypeptide receptor gene

Boylan

Jepeal

Wolfe

2006

American Journal of Physiology-Endocrinology and Metabolism

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-The physiological effects of glucose-dependent insulinotropic polypeptide (GIP) are mediated through specific receptors expressed on target cells. Because aberrant GIP receptor (GIPR) expression has been implicated in abnormal GIP responses associated with type 2 diabetes mellitus and food-induced Cushing's syndrome, we sought to identify factors that regulate the GIPR. We previously demonstrated that sequences between Ϫ1 and Ϫ100 of the GIPR gene were sufficient to direct transcription in a rat insulinoma cell line (RIN38). In the present study, we compared the 5Ј-flanking regions of the rat and human GIPR gene and demonstrated 88% identity within the first 92 bp. Subsequent serial deletion analyses showed that the region between Ϫ85 and Ϫ40 is essential for maximal promoter activity. Within this region, we identified three putative Sp1 binding motifs, located at positions Ϫ77, Ϫ60, and Ϫ50, that can specifically bind both Sp1 and Sp3. Whereas mutation of the Sp1 sites at Ϫ50 and Ϫ60 led to 36 and 40% reduction in promoter activity, respectively, mutation of the Sp1 motif at Ϫ70 did not affect promoter activity. Cotransfection of S2 Schneider cells with GIPR-luciferase chimeric constructs and either Sp1 or Sp3 expression vectors indicated that both Sp1 and the long form of Sp3 activate transcription through binding to the Sp1 sites located between Ϫ100 and Ϫ40. Lastly, chromatin immunoprecipitation analyses revealed that both Sp1 and Sp3 bind to the GIPR promoter region in RIN38 cells. These results indicate that cellspecific expression of GIPR is associated with the binding of the transcription factors Sp1 and Sp3 to the GIPR promoter. gastric inhibitory polypeptide; transcription factors; RIN38 cells; insulinoma; rat-2 cells; chromatin immunoprecipitation assay GLUCOSE-DEPENDENT INSULINOTROPIC POLYPEPTIDE (GIP) is a member of the secretin

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“…In the rat, transcripts arise from a single transcription start site and contain one or two 5Ј-untranslated exons, the second exon being mainly spliced out in mature mRNA (9,11). In human, G-R transcripts that included or not a 5Ј-untranslated exon located 5 kb upstream to the first coding exon have been reported (6,7,10). Whether or not these transcripts arise from distinct transcription start sites, and their relative abundance, remain to be elucidated.…”

Section: Discussionmentioning

confidence: 95%

Role of the Sp Family of Transcription Factors on Glucagon Receptor Gene Expression

Geiger

Salazar

Kervran

2001

Biochemical and Biophysical Research Communications

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Isolation and Structural-Analysis of the 5′ Flanking Region of the Gene Encoding the Human Glucagon Receptor

Cited by 17 publications

References 0 publications

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

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

Sp1/Sp3 binding is associated with cell-specific expression of the glucose-dependent insulinotropic polypeptide receptor gene

Role of the Sp Family of Transcription Factors on Glucagon Receptor Gene Expression

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