Novel Insulin Promoter- and Enhancer-Binding Proteins That Discriminate between Pancreatic α- and β-Cells
Autor: | Stefan Thor, Helena Ohlsson, Thomas Edlund |
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Rok vydání: | 1991 |
Předmět: |
medicine.medical_treatment
Molecular Sequence Data Regulatory Sequences Nucleic Acid Biology Cell Line Islets of Langerhans Mice Endocrinology Enhancer binding Gene expression medicine Animals Insulin Promoter Regions Genetic Molecular Biology Cell Nucleus Binding Sites Base Sequence GRB10 Cell Differentiation General Medicine Molecular biology IRS2 Rats DNA-Binding Proteins Insulin receptor Enhancer Elements Genetic medicine.anatomical_structure Gene Expression Regulation Regulatory sequence biology.protein Pancreas |
Zdroj: | Molecular Endocrinology. 5:897-904 |
ISSN: | 1944-9917 0888-8809 |
Popis: | In the mouse insulin is first detected on embryonic day 12 (e12) in a subpopulation of the cells that on e10 start to produce glucagon. During the continued embryonic development, the number of cells that coexpress the two hormones is gradually decreased, and in adults the expression of these two hormone genes is segregated to the beta- and alpha-cells. To begin to understand the process of terminal differentiation that restricts insulin gene expression to beta-cells, we have assayed for the presence of nuclear proteins that interact with transcriptional regulatory sequences of the rat insulin I gene in pancreatic alpha- and beta-cell lines. All except one of the previously identified insulin enhancer-binding proteins were found to be present in both cell types. A new insulin promoter-binding protein, IPF1, which was present in beta-cells but absent in alpha-cells, was identified. The beta-cell specificity of IPF1 implies that the insulin promoter is involved in the restriction of insulin gene expression to the beta-cells. The binding sites for IPF1 and the beta-cell-specific enhancer-binding protein IEF2 are both recognized by the previously isolated homeodomain-containing LIM protein isl-1, but these three proteins were all shown to be different entities. |
Databáze: | OpenAIRE |
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