title: Alterations in the phosphoproteomic profile of cells expressing a non-functional form of the SHP2 phosphatase.
abstract: The phosphatase SHP-2 plays an essential role in growth factor signaling and mutations in its locus is the cause of congenital and acquired pathologies. Mutations of SHP-2 are known to affect the activation of the RAS pathway. Gain-of-function mutations cause the Noonan syndrome, the most common non-chromosomal congenital disorder. In order to obtain a holistic picture of the intricate regulatory mechanisms underlying SHP-2 physiology and pathology, we set out to characterize perturbations of the cell phosphorylation profile caused by an altered localization of SHP-2. To describe the proteins whose activity may be directly or indirectly modulated by SHP-2 activity, we identified tyrosine peptides that are differentially phosphorylated in wild type SHP-2 cells and isogenic cells expressing a non-functional SHP-2 variant that cannot dephosphorylate the physiological substrates due to a defect in cellular localization upon growth factor stimulation. By an iTRAQ based strategy coupled to mass spectrometry, we have identified 63 phosphorylated tyrosine residues in 53 different proteins whose phosphorylation is affected by SHP-2 activity. Some of these confirm already established regulatory mechanisms while many others suggest new possible signaling routes that may contribute to the modulation of the ERK and p38 pathways by SHP-2. Interestingly many new proteins that we found to be regulated by SHP-2 activity are implicated in the formation and regulation of focal adhesions.
authors: Department of Biology, University of Rome Tor Vergata, Via della ricerca scientifica, 00133 Rome, Italy. Electronic address: salvatore.corallino@ifom.eu.
authors: Salvatore
authors: S
authors: Corallino
authors: Protein Networks Team, Division of Cancer Biology, Institute of Cancer Research, London SW3 6JB, United Kingdom.
authors: Leo K
authors: LK
authors: Iwai
authors: Protein Networks Team, Division of Cancer Biology, Institute of Cancer Research, London SW3 6JB, United Kingdom.
authors: Leo S
authors: LS
authors: Payne
authors: Protein Networks Team, Division of Cancer Biology, Institute of Cancer Research, London SW3 6JB, United Kingdom.
authors: Paul H
authors: PH
authors: Huang
authors: Department of Biology, University of Rome Tor Vergata, Via della ricerca scientifica, 00133 Rome, Italy.
authors: Francesca
authors: F
authors: Sacco
authors: Department of Biology, University of Rome Tor Vergata, Via della ricerca scientifica, 00133 Rome, Italy; IRCCS Fondazione Santa Lucia, 00143 Rome, Italy. Electronic address: Cesareni@uniroma2.it.
authors: Gianni
authors: G
authors: Cesareni
authors: Department of Biology, University of Rome Tor Vergata, Via della ricerca scientifica, 00133 Rome, Italy. Electronic address: Castagnoli@uniroma2.it.
authors: Luisa
authors: L
authors: Castagnoli
mesh_terms: D000818:Animals; D001709:Biotechnology; D057809:HEK293 Cells; D006801:Humans; D020935:MAP Kinase Signaling System; D013058:Mass Spectrometry; D051379:Mice; D008954:Models, Biological; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism; D041681:NIH 3T3 Cells; D010766:Phosphorylation; D019000:Phosphotyrosine / Q000378:metabolism; D040081:Protein Array Analysis; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11 / Q000235:genetics / Q000378:metabolism*; D040901:Proteomics
chemical_list: D050505:Mutant Proteins; D019000:Phosphotyrosine; C516724:PTPN11 protein, human; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; C516725:Ptpn11 protein, mouse