Abstract
ISL1 is a LIM homeodomain protein that plays an important role in insulin gene transcriptional activation and islet cell formation. BETA2 is a transcription factor in the basic helix-loop-helix (bHLH) family, which activates expression of tissue-specific genes in several developmental systems. In this study, we investigated the functional and physical interactions of ISL1 and BETA2 in promoting insulin gene transcription in non-beta cells. Using the luciferase assay, we demonstrated that ISL1 and BETA2 could activate insulin gene transcription synergistically. Co-immunoprecipitation also supported that ISL1 and BETA2 appear in one complex and this physical interaction mediates the synergy between these two proteins.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Basic Helix-Loop-Helix Transcription Factors / metabolism*
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Cells, Cultured
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Enhancer Elements, Genetic
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Gene Expression Regulation
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Homeodomain Proteins / genetics
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Homeodomain Proteins / metabolism*
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Humans
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Insulin / genetics*
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Insulin / metabolism
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LIM-Homeodomain Proteins
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Nerve Tissue Proteins / genetics
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Nerve Tissue Proteins / metabolism*
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Promoter Regions, Genetic
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Protein Binding / genetics
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Protein Binding / physiology*
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Recombinant Proteins
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Transcription Factors
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Transcription, Genetic / physiology*
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Transfection
Substances
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Basic Helix-Loop-Helix Transcription Factors
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Homeodomain Proteins
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Insulin
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LIM-Homeodomain Proteins
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NEUROD1 protein, human
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Nerve Tissue Proteins
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Recombinant Proteins
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Transcription Factors
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insulin gene enhancer binding protein Isl-1