Bovine steroid 21-hydroxylase: regulation of biosynthesis

Biochemistry. 1986 May 20;25(10):2846-53. doi: 10.1021/bi00358a016.


A recombinant cDNA clone, PBC21-1, specific for bovine steroid 21-hydroxylase cytochrome P-450 (P-450C21) was identified in a bovine adrenocortical cDNA library, and this identity was confirmed by nucleotide sequencing which revealed significant amino acid homology (77%) with human P-450C21 cDNA. The pBC21-1 insert is 1.7 kilobases in length and includes a 1128 base pair region that encodes the C-terminal 376 amino acids of bovine P-450C21 as well as 535 base pairs of 3'-untranslated sequence. A novel feature of this insert is a 20 base pair intervening sequence near the 5' end, apparently the result of an aberrant splicing event. Northern blot analysis reveals that bovine P-450C21 is encoded by two transcripts, 2.3 and 2.0 kilobases in length which are detected in adrenal cortical RNA. Bovine liver, heart, kidney, and corpus luteum do not contain detectable P-450C21 transcripts. Regulation of P-450C21 gene expression by adrenocorticotropin was investigated with pBC21-1 and bovine adrenocortical cells in primary, monolayer culture. Treatment with ACTH or analogues of cAMP increases the steady-state levels of P-450C21 RNA in such cell cultures. In vitro transcription run-on assays suggest that this increase is, at least in part, due to the enhanced transcriptional activity of the P-450C21 gene.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adrenal Cortex / enzymology
  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cattle
  • Cells, Cultured
  • Cloning, Molecular*
  • Cytochrome P-450 Enzyme System / biosynthesis
  • Cytochrome P-450 Enzyme System / genetics
  • DNA / metabolism*
  • DNA Restriction Enzymes
  • Humans
  • Kinetics
  • Mice
  • Nucleic Acid Hybridization
  • Organ Specificity
  • RNA / isolation & purification
  • Sequence Homology, Nucleic Acid
  • Species Specificity
  • Steroid 21-Hydroxylase / biosynthesis
  • Steroid 21-Hydroxylase / genetics*
  • Steroid Hydroxylases / genetics*
  • Swine
  • Transcription, Genetic*


  • RNA
  • DNA
  • Cytochrome P-450 Enzyme System
  • Steroid Hydroxylases
  • Steroid 21-Hydroxylase
  • DNA Restriction Enzymes

Associated data

  • GENBANK/K01333
  • GENBANK/M13461