Molecular identification of the apical Ca2+ channel in 1,25-dihydroxyvitamin D3-responsive epithelia
| Autor: | Peter H.G.M. Willems, C.H. van Os, K.F.J. van de Graaf, Joost G. J. Hoenderop, J.W.C.M. van der Kemp, René J. M. Bindels, Anita Hartog |
|---|---|
| Přispěvatelé: | Other departments |
| Rok vydání: | 1999 |
| Předmět: |
Calbindins
Moleculaire en funktionele karakterisering van Ca2+-kanalen in enterocyten TRPV6 TRPV5 Molecular Sequence Data Xenopus TRPV Cation Channels Nephron Biology Biochemistry Substrate Specificity S100 Calcium Binding Protein G Calcitriol Extracellular medicine Animals Amino Acid Sequence RNA Messenger Cloning Molecular Molecular Biology Ion channel Cells Cultured Role of subcellular rises in free cytosolic calcium concentration in the hormonal regulation of secretion and transport processes in epithelia Biological Transport Epithelial Cells Cell Biology Sequence Analysis DNA Apical membrane biology.organism_classification Immunohistochemistry Molecular and functional characterization of Ca2+ channels in enterocytes Cell biology medicine.anatomical_structure Kidney Tubules Calcium Calcium Channels Rabbits Sequence Alignment Rol van subcellulaire veranderingen van de cytoplasmatische calciumconcentratie bij de hormonale regulatie van secretie- en transportprocessen in epithelia Homeostasis |
| Zdroj: | Journal of Biological Chemistry, 274, 8375-8378 Journal of Biological Chemistry, 274, 13, pp. 8375-8378 Journal of biological chemistry, 274(13), 8375-8378. American Society for Biochemistry and Molecular Biology Inc. Journal of Biological Chemistry, 274, pp. 8375-8378 |
| ISSN: | 0021-9258 |
| Popis: | In mammals, the extracellular calcium concentration is maintained within a narrow range despite large variations in daily dietary input and body demand. The small intestine and kidney constitute the influx pathways into the extracellular Ca2+ pool and, therefore, play a primary role in Ca2+ homeostasis, We identified an apical Ca2+ influx channel, which is expressed in proximal small intestine, the distal part of the nephron and placenta. This novel epithelial Ca2+ channel (ECaC) of 730 amino acids contains six putative membrane-spanning domains with an additional hydrophobic stretch predicted to be the pore region. ECaC resembles the recently cloned capsaicin receptor and the transient receptor potential-related ion channels with respect to its predicted topology but shares less than 30% sequence homology with these channels. In kidney, ECaC is abundantly present in the apical membrane of Ca2+ transporting cells and colocalizes with 1,25-dihydroxyvitamin D-3-dependent calbindin-D-28K. ECaC expression in Xenopus oocytes confers Ca2+ influx with properties identical to those observed in distal renal cells. Thus, ECaC has the expected properties for being the gatekeeper of 1,25-dihydroxyvitamin D-3-dependent active transepithelial Ca2+ transport |
| Databáze: | OpenAIRE |
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