Identification of a goblet cell-specific enhancer element in the rat intestinal trefoil factor gene promoter bound by a goblet cell nuclear protein.
Intestinal trefoil factor (ITF) is selectively expressed in goblet cells of the small and large intestinal mucosa. Detailed analysis of the rat ITF (RITF) promoter was undertaken by transient transfection and gel mobility shift assays (GMSAs) using the goblet cell-like LS174T colon cancer-derived cell line. Various lengths of wild-type or mutant constructs of the 5'-flanking region were linked to the pXP2 reporter gene luciferase. Expression of -118 RITF was significantly decreased compared with -154 RITF, and transfection with an 18-base pair construct (-141 to -124) resulted in more than 5-fold greater expression than transfection with the promoterless pXP2 gene construct alone. Using various synthetic oligonucleotide mutants, GMSAs revealed that only a 9-base pair sequence (CCCCTCCCC) in this element was required for specific binding, overlapping but distinct from a Sp1-like element. GMSA demonstrated that this element was specifically bound by nuclear proteins from intestinal cells with a goblet cell-like phenotype. These studies demonstrate that a 9-base pair element (goblet cell response element) between -154 and -118 in the RITF promoter gene is a cis-active element bound by a distinct nuclear transcription factor and is capable of directing intestine and goblet cell-specific expression.
Ogata
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H
Gastrointestinal Unit and Center for the Study of Inflammatory Bowel Disease, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, USA.
Inoue
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N
Podolsky
D K
DK
D000818:Animals; D004742:Enhancer Elements, Genetic; D006133:Growth Substances / Q000235:genetics*; D006801:Humans; D007422:Intestines / Q000166:cytology*; D009077:Mucins; D009124:Muscle Proteins; D016296:Mutagenesis; D009479:Neuropeptides; D009687:Nuclear Proteins / Q000378:metabolism; D010455:Peptides / Q000235:genetics*; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D051381:Rats; D016329:Sp1 Transcription Factor / Q000378:metabolism; D014162:Transfection; D000071164:Trefoil Factor-2; D000071165:Trefoil Factor-3; D014407:Tumor Cells, Cultured
D006133:Growth Substances; D009077:Mucins; D009124:Muscle Proteins; D009479:Neuropeptides; D009687:Nuclear Proteins; D010455:Peptides; D016329:Sp1 Transcription Factor; C099037:TFF3 protein, rat; D000071164:Trefoil Factor-2; D000071165:Trefoil Factor-3