title: The mitochondrial reactive oxygen species regulator p66Shc controls PDGF-induced signaling and migration through protein tyrosine phosphatase oxidation.
abstract: Growth factor receptors induce a transient increase in reactive oxygen species (ROS) levels upon receptor binding to promote signaling through oxidation of protein tyrosine phosphatases (PTPs). Most studies have focused on NADPH oxidases as the dominant source of ROS to induce PTP oxidation. A potential additional regulator of growth factor-induced PTP oxidation is p66Shc, which stimulates mitochondrial ROS production. This study explores the contribution of p66Shc-induced ROS to PTP oxidation and growth factor receptor-induced signaling and migration through analyses of p66Shc-KO fibroblasts and cells with siRNA-mediated p66Shc downregulation. Analyses of PDGFβR phosphorylation in two independent cell systems demonstrated a decrease in PDGFβR phosphorylation after p66Shc deletion or downregulation, which occurred in a partially site-selective and antioxidant-sensitive manner. Deletion of p66Shc also reduced PDGF-induced activation of downstream signaling of Erk, Akt, PLCγ-1, and FAK. Importantly, reduced levels of p66Shc led to decreased oxidation of DEP1, PTP1B, and SHP2 after PDGF stimulation. The cell biological relevance of these findings was indicated by demonstration of a significantly reduced migratory response in PDGF-stimulated p66Shc-KO fibroblasts, consistent with reduced PDGFβR-Y1021 and PLCγ-1 phosphorylation. Downregulation of p66Shc also reduced EGFR phosphorylation and signaling, indicating that the positive role of p66Shc in receptor tyrosine kinase signaling is potentially general. Moreover, downregulation of the mitochondrial hydrogen peroxide scavenger peroxiredoxin 3 increased PDGFβR phosphorylation, showing that mitochondrial ROS in general promote PDGFβR signaling. This study thus identifies a previously unrecognized role for p66Shc in the regulation of PTP oxidation controlling growth factor-induced signaling and migration. In more general terms, the study indicates a regulatory role for mitochondrial-derived ROS in the control of PTP oxidation influencing growth factor signaling.
authors.affiliation: Department of Oncology-Pathology, Cancer Center Karolinska, Karolinska Institutet, 171 76 Stockholm, Sweden.
authors.forename: Jeroen
authors.initials: J
authors.lastname: Frijhoff
authors.affiliation: Department of Oncology-Pathology, Cancer Center Karolinska, Karolinska Institutet, 171 76 Stockholm, Sweden.
authors.forename: Markus
authors.initials: M
authors.lastname: Dagnell
authors.affiliation: Department of Oncology-Pathology, Cancer Center Karolinska, Karolinska Institutet, 171 76 Stockholm, Sweden.
authors.forename: Martin
authors.initials: M
authors.lastname: Augsten
authors.affiliation: Department of Experimental Oncology, European Institute of Oncology, 20142 Milan, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Beltrami
authors.affiliation: Department of Experimental Oncology, European Institute of Oncology, 20142 Milan, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Giorgio
authors.affiliation: Department of Oncology-Pathology, Cancer Center Karolinska, Karolinska Institutet, 171 76 Stockholm, Sweden. Electronic address: Arne.Ostman@ki.se.
authors.forename: Arne
authors.initials: A
authors.lastname: Östman
mesh_terms: D000818:Animals; D002465:Cell Movement / Q000235:genetics; D005347:Fibroblasts / Q000378:metabolism; D005609:Free Radicals / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D051379:Mice; D008928:Mitochondria / Q000378:metabolism; D041681:NIH 3T3 Cells; D010084:Oxidation-Reduction; D017027:Protein Tyrosine Phosphatases / Q000235:genetics / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D020797:Receptor, Platelet-Derived Growth Factor beta / Q000378:metabolism*; D055765:Shc Signaling Adaptor Proteins / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1
chemical_list: D005609:Free Radicals; D017382:Reactive Oxygen Species; D055765:Shc Signaling Adaptor Proteins; C528034:Shc1 protein, mouse; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D006861:Hydrogen Peroxide; D020797:Receptor, Platelet-Derived Growth Factor beta; D017027:Protein Tyrosine Phosphatases
keywords: Cysteine oxidation; Free radicals; Mitochondria; PDGF; Protein tyrosine phosphatase