کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1947089 1537318 2007 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
IGF-1 controls GLUT3 expression in muscle via the transcriptional factor Sp1
کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
IGF-1 controls GLUT3 expression in muscle via the transcriptional factor Sp1
چکیده انگلیسی
Glucose transporter 3 (GLUT3), while first found in human fetal muscle, is predominantly expressed in brain and neural tissue. By several independent techniques we have previously shown that GLUT3 is expressed in human skeletal muscle cells. The structure of the human GLUT3 gene has not been previously reported nor has there been any evaluation of the 5′-untranslated region (UTR). To this end, we have cloned and sequenced the human GLUT3 gene. Insulin-like growth factor-1 (IGF-1) increased endogenous Glut3 protein in cultured L6 myotubes, and similarly stimulated luciferase activity in a construct of the human GLUT3 5′-UTR linked to a luciferase reporter gene. Actinomycin D, an inhibitor of mRNA synthesis, prevented IGF-1 stimulation of Glut3 protein. Transfection of L6 cells with Sp1 increased Glut3 and augmented IGF-1 stimulation of Glut3 expression. Knockdown of Glut3 expression in cultured L6 muscle cells using small interference RNA (siRNA) specific for Glut3 significantly reduced myocyte glucose uptake. DNAse footprinting and gel shift assays showed Sp1 specifically bound to the human GLUT3 5′-UTR. Substitution mutants of the human GLUT3 5′-UTR luciferase construct indicated that only one of three Sp1 site clusters was involved in IGF-1 action. These data, using both a human GLUT3 5′-UTR construct and L6 cells' endogenous promoter, suggest that IGF-1 plays a role in maintaining muscle GLUT3 expression and basal glucose uptake via the transcriptional factor Sp1.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression - Volume 1769, Issues 11–12, November–December 2007, Pages 631-640
نویسندگان
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