Sequences near the CCAAT region and putative 1,25-dihydroxyvitamin D 3-response element and further upstream novel regulatory sequences of calbindin-D 28k promoter show DNase I footprinting protection

• Published in: Molecular and cellular endocrinology Vol. 75; no. 1; pp. 57 - 63
• Main Authors: Boland, Ricardo, Minghetti, Phillip P., Lowe, Karen E., Norman, Anthony W.
• Format: Journal Article
• Language: English
• Published: Elsevier Ireland Ltd 1991
• Subjects: Calbindin-D 28k promoter; Chick; DNase I footprinting; Intestine; lα,25-Dihydroxyvitamin D 3 receptor; Regulatory sequences; Calbindin-D 28k promoter; Intestine; Regulatory sequences; lα,25-Dihydroxyvitamin D 3 receptor; DNase I footprinting; Chick
• ISSN: 0303-7207; 1872-8057
• DOI: 10.1016/0303-7207(91)90245-N

1,25-Dihydroxyvitamin D 3, the hormonally active form of vitamin D (1,25(OH) 2D 3), plays a major role in the transcriptional regulation of the vitamin D-induced calcium binding protein calbindin-D 28k in the chick intestine. Sequence-specific protein-DNA interactions within the promoter of the calbindin-D 28k gene were studied by DNase I footprinting analysis to obtain information on the mechanism by which the 1,25(OH) 2D 3 receptor and other transcription factors regulate its expression. Restriction fragments spanning nucleotides −679 to +44 of the calbindin-D 28k 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 −592 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-D 28k 1,25(OH) 2D 3-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) 2D 3 receptor, revealed weaker protein-DNA interactions in these regions.