The Orphan Nuclear Receptors Steroidogenic Factor-1 and Liver Receptor Homolog-1: Structure, Regulation, and Essential Roles in Mammalian Reproduction

Physiol Rev. 2019 Apr 1;99(2):1249-1279. doi: 10.1152/physrev.00019.2018.

Abstract

Nuclear receptors are intracellular proteins that act as transcription factors. Proteins with classic nuclear receptor domain structure lacking identified signaling ligands are designated orphan nuclear receptors. Two of these, steroidogenic factor-1 (NR5A1, also known as SF-1) and liver receptor homolog-1 (NR5A2, also known as LRH-1), bind to the same DNA sequences, with different and nonoverlapping effects on targets. Endogenous regulation of both is achieved predominantly by cofactor interactions. SF-1 is expressed primarily in steroidogenic tissues, LRH-1 in tissues of endodermal origin and the gonads. Both receptors modulate cholesterol homeostasis, steroidogenesis, tissue-specific cell proliferation, and stem cell pluripotency. LRH-1 is essential for development beyond gastrulation and SF-1 for genesis of the adrenal, sexual differentiation, and Leydig cell function. Ovary-specific depletion of SF-1 disrupts follicle development, while LRH-1 depletion prevents ovulation, cumulus expansion, and luteinization. Uterine depletion of LRH-1 compromises decidualization and pregnancy. In humans, SF-1 is present in endometriotic tissue, where it regulates estrogen synthesis. SF-1 is underexpressed in ovarian cancer cells and overexpressed in Leydig cell tumors. In breast cancer cells, proliferation, migration and invasion, and chemotherapy resistance are regulated by LRH-1. In conclusion, the NR5A orphan nuclear receptors are nonredundant factors that are crucial regulators of a panoply of biological processes, across multiple reproductive tissues.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Breast Neoplasms / metabolism
  • Breast Neoplasms / pathology
  • Endometriosis / metabolism
  • Endometriosis / pathology
  • Female
  • Gene Expression Regulation
  • Humans
  • Leydig Cell Tumor / metabolism
  • Leydig Cell Tumor / pathology
  • Ligands
  • Male
  • Ovarian Neoplasms / metabolism
  • Ovarian Neoplasms / pathology
  • Pregnancy
  • Protein Conformation
  • Receptors, Cytoplasmic and Nuclear / chemistry
  • Receptors, Cytoplasmic and Nuclear / genetics
  • Receptors, Cytoplasmic and Nuclear / metabolism*
  • Reproduction*
  • Signal Transduction
  • Steroidogenic Factor 1 / chemistry
  • Steroidogenic Factor 1 / genetics
  • Steroidogenic Factor 1 / metabolism*
  • Structure-Activity Relationship
  • Testicular Neoplasms / metabolism
  • Testicular Neoplasms / pathology

Substances

  • Ligands
  • NR5A1 protein, human
  • NR5A2 protein, human
  • Receptors, Cytoplasmic and Nuclear
  • Steroidogenic Factor 1