title: Regulation of insulin gene expression by glucose and calcium in transfected primary islet cultures.
abstract: To study the regulation of insulin gene expression by physiological regulators, primary cultures of rat islet cells were transfected with portions of the rat insulin I gene 5'-flanking sequence linked to the reporter gene chloramphenicol acetyltransferase (CAT). Incubation of the cells in increasing glucose concentrations led to a parallel increase in both CAT activity and CAT mRNA levels. Pretreatment of the cells with the beta-cell-specific toxin streptozotocin reduced CAT activity 97%. Beta-Cell-specific expression of CAT was also demonstrated by co-staining the transfected cells with antisera to both CAT and insulin. Experiments showing a reduction in the response to glucose in the presence of the calcium channel blocker verapamil suggest that calcium plays a role in the glucose response, possibly via regulation of factors interacting with this limited portion of the insulin gene.
authors.affiliation: Hormone Research Institute, University of California, San Francisco 94143-0534.
authors.forename: M S
authors.initials: MS
authors.lastname: German
authors.forename: L G
authors.initials: LG
authors.lastname: Moss
authors.forename: W J
authors.initials: WJ
authors.lastname: Rutter
mesh_terms: D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology*; D002478:Cells, Cultured; D015500:Chloramphenicol O-Acetyltransferase / Q000096:biosynthesis; D016048:Dideoxyadenosine / Q000494:pharmacology; D005333:Fetus; D015870:Gene Expression / Q000187:drug effects*; D005947:Glucose / Q000494:pharmacology*; D007328:Insulin / Q000096:biosynthesis / Q000235:genetics*; D007515:Islets of Langerhans / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D013004:Somatostatin / Q000494:pharmacology; D014162:Transfection; D014700:Verapamil / Q000494:pharmacology
chemical_list: D007328:Insulin; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D016048:Dideoxyadenosine; D013004:Somatostatin; D003994:Bucladesine; D014700:Verapamil; D015500:Chloramphenicol O-Acetyltransferase; D005947:Glucose; D002118:Calcium