title: Sequences near the CCAAT region and putative 1,25-dihydroxyvitamin D3-response element and further upstream novel regulatory sequences of calbindin-D28k promoter show DNase I footprinting protection.
abstract: 1,25-Dihydroxyvitamin D3, the hormonally active form of vitamin D (1,25(OH)2D3), plays a major role in the transcriptional regulation of the vitamin D-induced calcium binding protein calbindin-D28k in the chick intestine. Sequence-specific protein-DNA interactions within the promoter of the calbindin-D28k gene were studied by DNAse I footprinting analysis to obtain information on the mechanism by which the 1,25(OH)2D3 receptor and other transcription factors regulate its expression. Restriction fragments spanning nucleotides -679 to +44 of the calbindin-D28k gene were used as probes Intestinal nuclear extracts prepared from vitamin D-deficient chicks generated several protected regions. Two prominent areas of protection against DNase I digestion were located at nucleotides -595 to -572 (21 bp) and -372 to -337 (36 bp). The -372 to -337 protected segment includes a CACCC sequence motif. Additional protection regions (-333/-328, -319/-315 and -308/-304) were observed within and near the candidate chicken calbindin-D28k 1,25(OH)2D3-response element (-329/-313) and the CCAAT box (-326/-322). DNase I digestion patterns obtained with liver nuclear extracts, containing low levels of 1,25(OH)2D3 receptor, revealed weaker protein-DNA interactions in these regions.
authors.affiliation: Division of Biomedical Sciences, University of California, Riverside 92521.
authors.forename: R
authors.initials: R
authors.lastname: Boland
authors.forename: P P
authors.initials: PP
authors.lastname: Minghetti
authors.forename: K E
authors.initials: KE
authors.lastname: Lowe
authors.forename: A W
authors.initials: AW
authors.lastname: Norman
mesh_terms: D000818:Animals; D001483:Base Sequence; D064026:Calbindins; D002117:Calcitriol / Q000494:pharmacology*; D002645:Chickens; D003850:Deoxyribonuclease I; D004386:Duodenum / Q000737:chemistry; D005786:Gene Expression Regulation / Q000187:drug effects; D008297:Male; D008969:Molecular Sequence Data; D009710:Nucleotide Mapping; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid; D064030:S100 Calcium Binding Protein G / Q000235:genetics*
chemical_list: D064026:Calbindins; D064030:S100 Calcium Binding Protein G; D003850:Deoxyribonuclease I; D002117:Calcitriol