title: Phosphoproteomics identified Endofin, DCBLD2, and KIAA0582 as novel tyrosine phosphorylation targets of EGF signaling and Iressa in human cancer cells.
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.
authors.affiliation: Oncology Research Institute, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors.forename: Yunhao
authors.initials: Y
authors.lastname: Chen
authors.forename: Teck-Yew
authors.initials: TY
authors.lastname: Low
authors.forename: Lee-Yee
authors.initials: LY
authors.lastname: Choong
authors.forename: Rajarshi Sankar
authors.initials: RS
authors.lastname: Ray
authors.forename: Yee-Ling
authors.initials: YL
authors.lastname: Tan
authors.forename: Weiyi
authors.initials: W
authors.lastname: Toy
authors.forename: Qingsong
authors.initials: Q
authors.lastname: Lin
authors.forename: Boon Keong
authors.initials: BK
authors.lastname: Ang
authors.forename: Chee Hong
authors.initials: CH
authors.lastname: Wong
authors.forename: Simin
authors.initials: S
authors.lastname: Lim
authors.forename: Bin
authors.initials: B
authors.lastname: Li
authors.forename: Choy-Leong
authors.initials: CL
authors.lastname: Hew
authors.forename: Newman Siu-Kwan
authors.initials: NS
authors.lastname: Sze
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Druker
authors.forename: Yoon-Pin
authors.initials: YP
authors.lastname: Lim
mesh_terms: D000595:Amino Acid Sequence; D045744:Cell Line, Tumor; D004815:Epidermal Growth Factor / Q000378:metabolism*; D000077156:Gefitinib; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000737:chemistry / Q000378:metabolism*; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D008869:Microtubule-Associated Proteins; D008969:Molecular Sequence Data; D009369:Neoplasms / Q000378:metabolism* / Q000473:pathology; D010750:Phosphoproteins / Q000737:chemistry / Q000378:metabolism*; D019000:Phosphotyrosine / Q000378:metabolism*; D040901:Proteomics; D011799:Quinazolines / Q000494:pharmacology*; D012697:Serine Endopeptidases / Q000737:chemistry / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D053719:Tandem Mass Spectrometry
chemical_list: C527270:CEP68 protein, human; C436326:DCBLD2 protein, human; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D008869:Microtubule-Associated Proteins; D010750:Phosphoproteins; D011799:Quinazolines; D019000:Phosphotyrosine; D004815:Epidermal Growth Factor; C116420:ZFYVE16 protein, human; D012697:Serine Endopeptidases; D000077156:Gefitinib