Transcaltachia, vesicular calcium transport, and microtubule-associated calbindin-D28K: emerging views of 1,25-dihydroxyvitamin D3-mediated intestinal calcium absorption.
Within the past 5 years it has become apparent that the biological actions of the seco-steroid 1,25-dihydroxyvitamin D3 are more complex than previously realized. Many cell types respond in both a classical genomic manner, as well as in a nongenomic fashion to 1,25(OH)2D3. In intestine, the presumptive nongenomic effects of the seco-steroid result in transcaltachia, the rapid, hormonal stimulation of calcium transport. To better understand nongenomic points of regulation in the intestine, studies were undertaken to identify the subcellular components of the 1,25(OH)2D3-stimulated calcium transport pathway. This research has revealed the existence of a vesicular transport mechanism, an involvement of microtubules, and microtubule-associated calbindin-D28K.
Nemere
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Department of Biochemistry, University of California, Riverside.
Norman
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AW
D000818:Animals; D001692:Biological Transport; D064092:Calbindin 1; D064026:Calbindins; D002117:Calcitriol / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D007408:Intestinal Absorption / Q000187:drug effects*; D008870:Microtubules / Q000502:physiology*; D051381:Rats; D064030:S100 Calcium Binding Protein G / Q000502:physiology*
C576500:Calb1 protein, rat; D064092:Calbindin 1; D064026:Calbindins; D064030:S100 Calcium Binding Protein G; D002117:Calcitriol; D002118:Calcium