Molecular cloning of cDNA and genomic DNA for human 25-hydroxyvitamin D3 1 alpha-hydroxylase

Biochem Biophys Res Commun. 1997 Oct 20;239(2):527-33. doi: 10.1006/bbrc.1997.7508.


The 25-hydroxyvitamin D3 1 alpha-hydroxylase (1 alpha-hydroxylase) is a cytochrome P450 enzyme that catalyzes the conversion of 25-hydroxyvitamin D3 to 1 alpha,25-dihydroxyvitamin D3. This enzyme plays an important role in calcium homeostasis. Here we report the molecular cloning of cDNA and gene for human 1 alpha-hydroxylase. The cDNA clone was obtained from a human kidney cDNA library by cross-hybridization with a previously cloned rat cDNA probe. The cDNA consists of 2469 bp and encodes a protein of 508 amino acids that shows 82.5% sequence identity with the rat enzyme. A computer-aided homology search revealed that 1 alpha-hydroxylase shares a relatively high homology with vitamin D3 25-hydroxylase (about 40% amino acid identity). Northern blot analysis showed that the 2.5-kb mRNA is most abundant in kidney. The gene for human 1 alpha-hydroxylase spans approximately 6 kb, is composed of nine exons, and is present as a single copy. This molecular cloning makes it possible to investigate the genetic mechanism of diseases related to calcium metabolism, including vitamin D-dependency rickets type I.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 25-Hydroxyvitamin D3 1-alpha-Hydroxylase / genetics*
  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cloning, Molecular
  • DNA / isolation & purification*
  • DNA, Complementary / isolation & purification*
  • Exons
  • Genes*
  • Genomic Library
  • Humans
  • Introns
  • Male
  • Molecular Sequence Data
  • Organ Specificity / drug effects
  • RNA, Messenger / metabolism
  • Rats


  • DNA, Complementary
  • RNA, Messenger
  • DNA
  • 25-Hydroxyvitamin D3 1-alpha-Hydroxylase

Associated data

  • GENBANK/AB005038
  • GENBANK/AB006987