mTOR/S6K1 and MAPK/RSK signaling pathways coordinately regulate estrogen receptor alpha serine 167 phosphorylation

FEBS Lett. 2010 Jan 4;584(1):124-8. doi: 10.1016/j.febslet.2009.11.041.


Resistance to anti-estrogen therapy is a major clinical concern in treatment of breast cancer. Estrogen-independent phosphorylation of estrogen receptor alpha, specifically on Ser167, is one of the contributing causes to development of resistance, and a prognostic marker for the disease. Here, we dissect the signaling pathways responsible for Ser167 phosphorylation. We report that the mTOR/S6K1 and MAPK/RSK contribute non-overlapping inputs into ERalpha activation via Ser167 phosphorylation. This cooperation may be targeted in breast cancer treatment by a combination of mTOR and MAPK inhibitors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Breast Neoplasms / drug therapy
  • Breast Neoplasms / metabolism
  • Cell Line, Tumor
  • Estrogen Receptor alpha / metabolism*
  • Female
  • Humans
  • Mitogen-Activated Protein Kinase Kinases / metabolism*
  • Phosphorylation
  • Protein Kinases / metabolism*
  • Ribosomal Protein S6 Kinases, 90-kDa / metabolism*
  • Serine / metabolism
  • Signal Transduction
  • TOR Serine-Threonine Kinases
  • Transcription, Genetic


  • Estrogen Receptor alpha
  • estrogen receptor alpha, human
  • Serine
  • Protein Kinases
  • MTOR protein, human
  • TOR Serine-Threonine Kinases
  • RPS6KA1 protein, human
  • Ribosomal Protein S6 Kinases, 90-kDa
  • Mitogen-Activated Protein Kinase Kinases