Phosphoproteomics identified Endofin, DCBLD2, and KIAA0582 as novel tyrosine phosphorylation targets of EGF signaling and Iressa in human cancer cells.
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.
Chen
Yunhao
Y
Oncology Research Institute, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
Low
Teck-Yew
TY
Choong
Lee-Yee
LY
Ray
Rajarshi Sankar
RS
Tan
Yee-Ling
YL
Toy
Weiyi
W
Lin
Qingsong
Q
Ang
Boon Keong
BK
Wong
Chee Hong
CH
Lim
Simin
S
Li
Bin
B
Hew
Choy-Leong
CL
Sze
Newman Siu-Kwan
NS
Druker
Brian J
BJ
Lim
Yoon-Pin
YP
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
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