Identification of the deoxyribonucleic acid-binding site of a regulatory protein involved in prostate-specific and androgen receptor-dependent gene expression

Endocrinology. 1999 May;140(5):2063-70. doi: 10.1210/endo.140.5.6696.

Abstract

In this study, we used a 5'-flanking region (-426/+28) of the rat prostatic probasin (rPB) gene shown to be sufficient to direct prostate-specific expression in transgenic mice in identifying the exact DNA-binding site of a putative prostate-specific transcription factor. Chloramphenicol acetyl transferase (CAT)-reporter gene analyses revealed that the construct pCAT PB -244/+52 was equally well induced by androgens in both prostatic LNCaP and nonprostatic COS-1, MCF-7, HEC-1, and HEP-1 cell lines, indicating that although the probasin gene region -244/+52 was important for androgen regulation, it was not regulated in a prostate-specific manner. Further studies suggested that the region -278/-240 was most crucial for prostate-specific expression. The sequence -426/-279 could be considered a silencer area, especially in nonprostatic cells. In deoxyribonuclease I footprinting, a protected 12-bp region was found between the nucleotides -251 and -240 only with nuclear extracts of prostatic origin. Deletion of this area decreased androgen induction significantly (P < 0.05) in transient transfections of prostatic cells compared with the wild-type reporter construct. Glucocorticoids were incapable of increasing the induction of the pCAT PB -278/+52 reporter construct compared with that of pCAT PB -244/+52 in the prostatic cell line LNCaP, suggesting that the putative prostate-specific protein acts as an inducer only when androgen and androgen receptor are present.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Androgen-Binding Protein / genetics*
  • Animals
  • Binding Sites
  • Breast Neoplasms
  • COS Cells
  • DNA / metabolism*
  • Endometrial Neoplasms
  • Female
  • Gene Expression*
  • Humans
  • Liver Neoplasms
  • Male
  • Mice
  • Mice, Transgenic
  • Mutagenesis, Site-Directed
  • Prostate / metabolism*
  • Prostatic Neoplasms
  • Rats
  • Receptors, Androgen / physiology*
  • Tumor Cells, Cultured

Substances

  • Androgen-Binding Protein
  • Receptors, Androgen
  • probasin
  • DNA