Detection of the human glucagon-like peptide 1(7-36) amide receptor on insulinoma-derived cell membranes.
125I-glucagon-like peptide 1(7-36)amide was covalently cross-linked to a specific binding protein in human insulinoma cell membranes. A single radiolabeled band at M(r) 63,000 was identified by SDS-PAGE after solubilization of the ligand-binding protein complex. The molecular weight of this apparent GLP-1 receptor in human endocrine pancreatic tissue was of identical size as the GLP-1 receptor on rat insulinoma-derived RINm5F cell membranes. The radiolabeled band was undetectable when 1 microM of unlabeled GLP-1(7-36)amide or of the GLP-1 antagonist exendin(9-39)amide was included in the binding assay. Utilizing isolated poly-A+ RNA from the human insulinoma and a 1,500 bp Eco-RI fragment of the cDNA coding for the rat GLP-1(7-36)amide receptor for Northern blot analysis, a main hybridization signal at about 7 kb was found by Northern blotting. Our data provide the first direct evidence of the existence of GLP-1 receptors in human endocrine pancreatic tissue.
Lankat-Buttgereit
B
B
Department of Internal Medicine, Philipps University of Marburg, FRG.
Göke
R
R
Stöckmann
F
F
Jiang
J
J
Fehmann
H C
HC
Göke
B
B
D000818:Animals; D002462:Cell Membrane / Q000737:chemistry; D005934:Glucagon; D052216:Glucagon-Like Peptide 1; D000067757:Glucagon-Like Peptide-1 Receptor; D004763:Glucagon-Like Peptides; D006801:Humans; D007340:Insulinoma / Q000378:metabolism*; D007515:Islets of Langerhans / Q000737:chemistry / Q000378:metabolism; D010190:Pancreatic Neoplasms / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism*; D051381:Rats; D011956:Receptors, Cell Surface / Q000032:analysis*; D018027:Receptors, Glucagon; D014407:Tumor Cells, Cultured
C000593833:GLP1R protein, human; C000593835:Glp1r protein, rat; D000067757:Glucagon-Like Peptide-1 Receptor; D010446:Peptide Fragments; D011956:Receptors, Cell Surface; D018027:Receptors, Glucagon; C055453:glucagon-like peptide 1 (7-36)amide; D004763:Glucagon-Like Peptides; D052216:Glucagon-Like Peptide 1; D005934:Glucagon