کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1930212 1050493 2012 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Rat glucagon receptor mRNA is directly regulated by glucose through transactivation of the carbohydrate response element binding protein
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Rat glucagon receptor mRNA is directly regulated by glucose through transactivation of the carbohydrate response element binding protein
چکیده انگلیسی

The glucagon receptor (Gcgr) is essential for maintaining glucose homeostasis in the liver and for stimulating insulin secretion in pancreatic β-cells. Glucose induces rat Gcgr mRNA expression; however, the precise mechanism remains unknown. We previously have studied the role of the carbohydrate response element binding protein (ChREBP), a glucose-activated transcription factor, in the regulation of glucose-stimulated gene expression. The G-box has previously been reported to be responsible for glucose regulation of Gcgr mRNA expression. The G-box comprises two E-boxes separated by 3 bp, which distinguishes it from the carbohydrate response element (ChoRE), which has 5-bp spacing between the two E-boxes. In the rat Gcgr promoter, a putative ChoRE (−554 bp/−538 bp) is localized near the G-box (−543 bp/−529 bp). In rat INS-1E insulinoma cells, deletion studies of the rat Gcgr promoter show that ChoRE is a minimal glucose response element. Moreover, reporter assays using a pGL3 promoter vector, which harbors ChoRE and chromatin immunoprecipitation assays reveal that ChoRE is a functional glucose response element in the rat Gcgr promoter. Furthermore, In contrast, glucagon partly suppresses glucose-induced expression of Gcgr mRNA. Thus, ChREBP directly regulates rat Gcgr expression in INS-1E cells. In addition, negative feedback looping between ChREBP and GCGR may further contribute to the regulation of glucose-induced gene expression.


► ChREBP directly induces rat glucagon receptor (Gcgr) mRNA expression.
► ChoRE is a functional glucose response element in the rat Gcgr promoter.
► Glucagon partly suppresses glucose-induced expression of Gcgr mRNA.
► A closed loop between glucose and glucagon signals regulates Gcgr expression.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochemical and Biophysical Research Communications - Volume 417, Issue 4, 27 January 2012, Pages 1107–1112
نویسندگان
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