Tissue-specific promoters regulate aromatase cytochrome P450 expression

Clin Chem. 1993 Feb;39(2):317-24.

Abstract

In humans, estrogen biosynthesis occurs in several tissue sites, including ovary, placenta, adipose, and brain. Recent work from our laboratory indicates that tissue-specific expression of aromatase cytochrome P450 (P450arom), the enzyme responsible for estrogen biosynthesis, is determined, in part, by the use of tissue-specific promoters. Thus, the expression of P450arom in human ovary appears to utilize a promoter proximal to the translation start site. This promoter is not utilized in placenta; instead, the promoter used to drive aromatase expression in placenta is > or = 40 kb upstream from the translational start site. In addition, a minor promoter used in the expression of a small proportion of placental transcripts is 9 kb upstream from the start of translation. Transcripts from these promoters are also expressed in other fetal tissues, including placenta-related cells such as JEG-3 choriocarcinoma cells and hydatidiform moles and other fetal tissues such as fetal liver. In adipose tissue, on the other hand, expression of P450arom may be achieved by yet another, adipose-specific promoter. The various 5'-untranslated exons unique for expression driven by each of these promoters are spliced into a common intron/exon boundary upstream from the translational start site. This means that the protein expressed in each of the various tissue-specific sites of estrogen biosynthesis is identical.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Aromatase / chemistry
  • Aromatase / genetics*
  • Female
  • Gene Expression Regulation*
  • Humans
  • Molecular Sequence Data
  • Organ Specificity
  • Ovary / metabolism
  • Promoter Regions, Genetic*

Substances

  • Aromatase