Related Experiment Video

Updated: May 10, 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

Functional domains of androgen receptor coactivator p44/Mep50/WDR77and its interaction with Smad1

Yirong Li1, Liantian Tian, Martin Ligr

  • 1Department of Pathology, New York University School of Medicine, New York, New York, USA.

Plos One
|June 5, 2013
PubMed

Insights

The p44 protein interacts with the androgen receptor (AR) and Smad1, forming a novel transcription complex. Its N-terminal region is crucial for this interaction and prostate cancer growth inhibition.

Area of Science:

  • Molecular biology
  • Endocrinology
  • Cancer research

Background:

  • p44 (also known as MEP50/WDR77) acts as a coactivator for the androgen receptor (AR).
  • p44 exhibits distinct functions in promoting or suppressing growth in endocrine organs and associated cancers.

Purpose of the Study:

  • To dissect the functional domains of p44.
  • To identify p44's role in protein interactions with transcription factors.
  • To understand p44's transcriptional activation and growth inhibition functions in prostate cancer.

Main Methods:

  • Yeast two-hybrid screening to identify interacting proteins.
  • Co-immunoprecipitation to confirm physical interactions.
  • Luciferase assays to assess functional interactions in human prostate cancer cells.
  • Cell proliferation assays using deletion mutants of p44.

Main Results:

  • A novel transcription complex, AR-p44-Smad1, was identified and confirmed.
  • The N-terminal region of p44, not the C-terminal WD40 domain, mediates interaction with AR and Smad1.
  • Both N- and C-terminal domains of p44 are needed for maximal AR transcriptional activation, but the N-terminus alone supports basic activation.
  • The central portion of p44 is essential for its role in inhibiting prostate cancer cell growth.

Conclusions:

  • p44 interacts with AR and Smad1 via its N-terminal region, forming a functional transcription complex.
  • p44's central domain is critical for mediating its growth-inhibitory effects in prostate cancer.

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