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Biochemical Reconstitution of Steroid Receptor•Hsp90 Protein Complexes and Reactivation of Ligand Binding
11:07

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Published on: September 21, 2011

Steroid receptor coactivator-1 and its family members differentially regulate transactivation by the tumor suppressor

S K Lee1, H J Kim, J W Kim

  • 1Department of Biology, Chonnam National University, Kwangju, Korea.

Molecular Endocrinology (Baltimore, Md.)
|November 7, 1999
PubMed

Insights

The tumor suppressor protein p53 interacts with steroid receptor coactivator-1 (SRC-1) family members. These interactions differentially modulate p53-mediated gene activation, impacting cell cycle regulation.

Area of Science:

  • Molecular Biology
  • Cancer Research
  • Cell Biology

Background:

  • The tumor suppressor protein p53 is a transcription factor regulating cell cycle.
  • Steroid receptor coactivator-1 (SRC-1) and its family members are coactivators for nuclear receptors.

Purpose of the Study:

  • To investigate the interaction between p53 and SRC-1 family members.
  • To determine how these interactions affect p53-mediated transactivation.

Main Methods:

  • Yeast and mammalian two-hybrid assays.
  • Glutathione S-transferase (GST) pull-down assays.
  • Cotransfection of HeLa cells with expression vectors.

Main Results:

  • p53 physically interacts with SRC-1, p/CIP, xSRC-3, and AIB1.
  • SRC-1 and p/CIP potentiated p53-mediated transactivation.
  • AIB1 and xSRC-3 repressed p53-mediated transactivation.
  • All SRC-1 members stimulated nuclear receptor and AP-1 transactivation.

Conclusions:

  • SRC-1 family members differentially modulate p53 transactivation in vivo.
  • These findings reveal a novel regulatory mechanism for p53 function.

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