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Updated: Aug 14, 2026

Detecting the Ligand-binding Domain Dimerization Activity of Estrogen Receptor Alpha Using the Mammalian Two-Hybrid Assay
09:07

Detecting the Ligand-binding Domain Dimerization Activity of Estrogen Receptor Alpha Using the Mammalian Two-Hybrid Assay

Published on: December 19, 2018

Negative regulation of estrogen receptor alpha transactivation functions by LIM domain only 4 protein

Rajesh R Singh1, Christopher J Barnes, Amjad H Talukder

  • 1Department of Molecular and Cellular Oncology, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030, USA.

Cancer Research
|November 17, 2005
PubMed

Insights

LIM domain only 4 (LMO4) acts as a corepressor for estrogen receptor alpha (ERalpha) in breast cells. LMO4 negatively regulates ERalpha activity, potentially promoting breast cancer progression by enabling ERalpha-negative phenotypes.

Area of Science:

  • Molecular Biology
  • Cancer Biology
  • Epigenetics

Background:

  • LIM domain only 4 (LMO4) is a transcriptional coregulatory protein.
  • Estrogen receptor alpha (ERalpha) plays a key role in breast cell function and cancer.
  • Metastasis tumor antigen 1 (MTA1) is an ERalpha corepressor.

Purpose of the Study:

  • To identify novel binding partners of LMO4.
  • To investigate the role of LMO4 in ERalpha transactivation.
  • To elucidate the function of LMO4 in breast cancer progression.

Main Methods:

  • Co-immunoprecipitation assays to identify protein interactions.
  • Chromatin immunoprecipitation to assess ERalpha recruitment.
  • Gene expression analysis to evaluate ERalpha-regulated genes.

Main Results:

  • LMO4 directly binds to ERalpha and MTA1, forming a complex with histone deacetylases (HDACs).
  • LMO4 overexpression represses ERalpha transactivation in an HDAC-dependent manner.
  • Silencing LMO4 enhances ERalpha recruitment, activity, and target gene expression.

Conclusions:

  • LMO4 is a component of the MTA1 corepressor complex and negatively regulates ERalpha transactivation in breast cells.
  • LMO4's repression of ERalpha may contribute to breast cancer progression by promoting ERalpha-negative phenotypes and aggressiveness.

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