Molecular structure of the chicken vitamin D-induced calbindin-D28K gene reveals eleven exons, six Ca2+-binding domains, and numerous promoter regulatory elements.

The seco-steroid hormone 1,25-dihydroxyvitamin D3 is known to induce the expression of a calcium binding protein termed calbindin-D28K in a variety of target tissues. In order to comprehend the mechanism of induction we have cloned and sequenced the chicken calbindin-D28K gene. The gene spans some 18.

Expression of calbindin-D28K mRNA as a function of altered serum calcium and phosphorus levels in vitamin D-replete chick intestine.

The availability of specific cDNA probes to the chick intestinal calbindin-D28K (CaBP) mRNA has allowed us to assess the regulation of this mRNA in response to 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) administration. It has previously been demonstrated that dietary calcium and phosphorus can effect alterations in the steady-state intestinal levels of chick CaBP. We have examined whether or not perturbations in dietary calcium and phosphorus have an effect on the expression of the intestinal mRNA coding for CaBP in the vitamin D-replete chick.

Regulation of calbindin-D28K gene expression by 1,25-dihydroxyvitamin D3 is correlated to receptor occupancy.

1,25-Dihydroxyvitamin D3 (1,25-(OH)2D3) induces the synthesis of calcium binding protein (calbindin-D28K) and calbindin-D28K-mRNA in the chick intestine. We have examined the relationship between nuclear uptake of 1,25-(OH)2D3, 1,25-(OH)2D3 receptor occupancy levels, and transcription of the calbindin-D28K gene and found all three parameters to be highly correlated. All three events occur rapidly (within 15-30 min) following a single dose of 6.

Effects of alpha-amanitin and cycloheximide on 1,25-dihydroxyvitamin D3-dependent calbindin-D28K and its mRNA in vitamin D3-replete chick intestine.

We have examined the effects of the transcriptional inhibitor alpha-amanitin and the translational inhibitor cycloheximide on levels of calbindin-D28K (28-kDa calcium binding protein, CaBP) and CaBP-mRNA in the vitamin D-replete chick intestine. Chicks were raised on one of four diets: "normal" (1% calcium, 0.6% phosphorus); high calcium (3.

Characterization of the calf uterine progesterone receptor and its stabilization by nucleic acids.

The molecular and steroid hormone-binding properties of the calf uterine progesterone receptor and its interaction with nucleic acids were investigated. A positive cooperative binding interaction of [3H]progesterone with the receptor was evident from a nonlinear Scatchard plot and a Hill coefficient of 1.22 +/- 0.