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Progesterone receptor transcription and non-transcription signaling mechanisms

Susan A Leonhardt1, Viroj Boonyaratanakornkit, Dean P Edwards

  • 1Department of Pathology B216, School of Medicine University of Colorado Health Sciences Center, 4200 East Ninth Avenue, Campus Box B216, Denver, CO 80262, USA.

Steroids
|December 12, 2003
PubMed

Insights

The progesterone receptor (PR) mediates diverse effects, targeted by RU486, a potent antagonist. Novel non-genomic PR actions in the cytoplasm and cell membrane are also reviewed.

Area of Science:

  • Endocrinology
  • Molecular Biology
  • Cell Biology

Background:

  • The progesterone receptor (PR) is a nuclear receptor crucial for female reproductive tissues.
  • PR is a key therapeutic target in reproductive health and endocrine-dependent cancers.
  • RU486 is a widely used PR antagonist with complex inhibitory mechanisms.

Purpose of the Study:

  • To review the mechanism of action of the PR antagonist RU486.
  • To explore novel extra-nuclear functions of PR.
  • To discuss the biological implications of non-genomic PR signaling.

Main Methods:

  • Review of existing literature on PR mechanism of action.
  • Analysis of RU486's antagonistic activities.
  • Examination of recent findings on extra-nuclear PR signaling.

Main Results:

  • RU486 acts as a competitive antagonist and exhibits "active antagonism" by inhibiting PR agonist complexes.
  • Active antagonism involves heterodimerization, DNA-binding competition, and corepressor recruitment.
  • A subpopulation of PR in the cytoplasm/cell membrane mediates rapid, non-genomic progesterone signaling.

Conclusions:

  • RU486's potency stems from both competitive and active antagonism.
  • Extra-nuclear PR signaling represents a novel pathway for progesterone action.
  • Understanding these diverse PR mechanisms is vital for reproductive medicine and cancer therapy.

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