Kidney microsomal 25- and 1α-hydroxylase in vitamin D metabolism: catalytic properties, molecular cloning, cellular localization and expression during development
| Autor: | Kjell Wikvall, Maria Norlin, Fardin Hosseinpour |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Swine
Immunoblotting 25-Hydroxyvitamin D3 1-alpha-hydroxylase Molecular cloning Biology Kidney Transfection Kidney Tubules Proximal chemistry.chemical_compound Microsomes Vitamin D and neurology medicine Animals Cloning Molecular Molecular Biology Cellular localization Cholecalciferol 25-Hydroxyvitamin D3 1-alpha-Hydroxylase COS cells Hydroxycholecalciferols Age Factors Nucleotide Mapping Cytochrome P450 Cell Biology Immunohistochemistry Molecular biology medicine.anatomical_structure Liver chemistry Biochemistry COS Cells Steroid Hydroxylases biology.protein Cholestanetriol 26-Monooxygenase |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids. 1580:133-144 |
| ISSN: | 1388-1981 |
| DOI: | 10.1016/s1388-1981(01)00192-5 |
| Popis: | Both a 25-hydroxylation and a 1alpha-hydroxylation are necessary for the conversion of vitamin D(3) into the calcium-regulating hormone 1alpha,25-dihydroxyvitamin D(3). According to current knowledge, the hepatic mitochondrial cytochrome P450 (CYP) 27A and microsomal CYP2D25 are able to catalyze the former bioactivation step. Substantial 25-hydroxylase activity has also been demonstrated in kidney. This paper describes the molecular cloning and characterization of a microsomal vitamin D(3) 25- and 1alpha-hydroxylase in kidney. The enzyme purified from pig kidney and the recombinant enzyme expressed in COS cells catalyzed 25-hydroxylation of vitamin D(3) and 1alpha-hydroxyvitamin D(3) and, in addition, 1alpha-hydroxylation of 25-hydroxyvitamin D(3). The cDNA encodes a protein of 500 amino acids. Both the DNA sequence and the deduced peptide sequence of the renal enzyme are homologous with those of the hepatic vitamin D(3) 25-hydroxylase CYP2D25. Genomic Southern blot analysis suggested the presence of a single gene for CYP2D25 in the pig. Immunohistochemistry experiments indicated that CYP2D25 is expressed almost exclusively in the cells of cortical proximal tubules. The expression of CYP2D25 in kidney, but not in liver, was much higher in the adult pig than in the newborn. These findings indicate a tissue-specific developmental regulation of CYP2D25. The results from the current and previous studies on renal vitamin D hydroxylations imply that CYP2D25 has a biological role in kidney. |
| Databáze: | OpenAIRE |
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