Phosphoproteomics identified Endofin, DCBLD2, and KIAA0582 as novel tyrosine phosphorylation targets of EGF signaling and Iressa in human cancer cells

Proteomics. 2007 Jul;7(14):2384-97. doi: 10.1002/pmic.200600968.

Abstract

With the completion of the human genome project, analysis of enriched phosphotyrosyl proteins from epidermal growth factor (EGF)-induced phosphotyrosine proteome permits the identification of novel downstream substrates of the EGF receptor (EGFR). Using cICAT-based LC-MS/MS method, we identified and relatively quantified the tyrosine phosphorylation levels of 21 proteins between control and EGF-treated A431 human cervical cancer cells. Of these, Endofin, DCBLD2, and KIAA0582 were validated to be novel tyrosine-phosphorylation targets of EGF signaling and Iressa, a highly selective inhibitor of EGFR. In addition, EGFR activity was shown to be necessary for EGF-induced localization of Endofin, an FYVE domain-containing protein regulated by phosphoinositol lipid and engaged in endosome-mediated receptor modulation. Although several groups have conducted phosphoproteomics of EGF signaling in recent years, our study is the first to identify and validate Endofin, DCBLD2, and KIAA0582 as part of a complex EGF phosphotyrosine signaling network. These novel data will provide new insights into the complex EGF signaling and may have implications on target-directed cancer therapeutics.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Cell Line, Tumor
  • Epidermal Growth Factor / metabolism*
  • Gefitinib
  • Humans
  • Intracellular Signaling Peptides and Proteins / chemistry
  • Intracellular Signaling Peptides and Proteins / metabolism*
  • Membrane Proteins / chemistry
  • Membrane Proteins / metabolism*
  • Microtubule-Associated Proteins
  • Molecular Sequence Data
  • Neoplasms / metabolism*
  • Neoplasms / pathology
  • Phosphoproteins / chemistry
  • Phosphoproteins / metabolism*
  • Phosphotyrosine / metabolism*
  • Proteomics
  • Quinazolines / pharmacology*
  • Serine Endopeptidases / chemistry
  • Serine Endopeptidases / metabolism*
  • Signal Transduction* / drug effects
  • Tandem Mass Spectrometry

Substances

  • CEP68 protein, human
  • DCBLD2 protein, human
  • Intracellular Signaling Peptides and Proteins
  • Membrane Proteins
  • Microtubule-Associated Proteins
  • Phosphoproteins
  • Quinazolines
  • Phosphotyrosine
  • Epidermal Growth Factor
  • ZFYVE16 protein, human
  • Serine Endopeptidases
  • Gefitinib