Tumor necrosis factor receptor-associated factor family protein 2 is a key mediator of the epidermal growth factor-induced ribosomal S6 kinase 2/cAMP-responsive element-binding protein/Fos protein signaling pathway

J Biol Chem. 2012 Jul 27;287(31):25881-92. doi: 10.1074/jbc.M112.359521. Epub 2012 Jun 8.

Abstract

TRAF2 has an important function in mediating the TNF-R signaling pathway toward activation of NF-κB and JNKs. Here we reveal a novel function of TRAF2 in the epidermal growth factor (EGF) signaling pathway. Knockdown of TRAF2 blocked EGF-induced AP-1 activity and anchorage- independent cell transformation. Notably, we showed that EGF induces ribosomal S6 kinase 2 (RSK2) ubiquitination, and knocking down TRAF2 suppresses ubiquitination of RSK2 induced by EGF. We also found that TRAF2 affects RSK2 activity through RSK2 ubiquitination. RSK2 plays a critical role in AP-1 activity mediated through CREB and c-Fos, which regulates anchorage-independent cell transformation. In addition, TRAF2 is overexpressed in colon cancer and required for colon cancer development, suggesting that TRAF2 might be a potential molecular target for cancer prevention and treatment.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line, Tumor
  • Cell Proliferation
  • Cell Transformation, Neoplastic / metabolism
  • Colorectal Neoplasms / metabolism
  • Colorectal Neoplasms / pathology
  • Cyclic AMP Response Element-Binding Protein / metabolism*
  • Epidermal Growth Factor / physiology*
  • Female
  • Gene Knockdown Techniques
  • Humans
  • Mice
  • Mice, Nude
  • Neoplasm Transplantation
  • Polyubiquitin / metabolism
  • Protein Binding
  • Protein Processing, Post-Translational
  • Proto-Oncogene Proteins c-fos / metabolism*
  • Ribosomal Protein S6 Kinases, 90-kDa / metabolism*
  • Signal Transduction
  • TNF Receptor-Associated Factor 2 / genetics
  • TNF Receptor-Associated Factor 2 / metabolism*
  • Transcription Factor AP-1 / metabolism
  • Transcription, Genetic
  • Tumor Burden
  • Ubiquitination

Substances

  • Cyclic AMP Response Element-Binding Protein
  • Proto-Oncogene Proteins c-fos
  • TNF Receptor-Associated Factor 2
  • Transcription Factor AP-1
  • Polyubiquitin
  • Epidermal Growth Factor
  • Ribosomal Protein S6 Kinases, 90-kDa
  • ribosomal protein S6 kinase, 90kDa, polypeptide 3