title: Regulation of Platelet Derived Growth Factor Signaling by Leukocyte Common Antigen-related (LAR) Protein Tyrosine Phosphatase: A Quantitative Phosphoproteomics Study.
abstract: Intracellular signaling pathways are reliant on protein phosphorylation events that are controlled by a balance of kinase and phosphatase activity. Although kinases have been extensively studied, the role of phosphatases in controlling specific cell signaling pathways has been less so. Leukocyte common antigen-related protein (LAR) is a member of the LAR subfamily of receptor-like protein tyrosine phosphatases (RPTPs). LAR is known to regulate the activity of a number of receptor tyrosine kinases, including platelet-derived growth factor receptor (PDGFR). To gain insight into the signaling pathways regulated by LAR, including those that are PDGF-dependent, we have carried out the first systematic analysis of LAR-regulated signal transduction using SILAC-based quantitative proteomic and phosphoproteomic techniques. We haveanalyzed differential phosphorylation between wild-type mouse embryo fibroblasts (MEFs) and MEFs in which the LAR cytoplasmic phosphatase domains had been deleted (LARΔP), and found a significant change in abundance of phosphorylation on 270 phosphosites from 205 proteins because of the absence of the phosphatase domains of LAR. Further investigation of specific LAR-dependent phosphorylation sites and enriched biological processes reveal that LAR phosphatase activity impacts on a variety of cellular processes, most notably regulation of the actin cytoskeleton. Analysis of putative upstream kinases that may play an intermediary role between LAR and the identified LAR-dependent phosphorylation events has revealed a role for LAR in regulating mTOR and JNK signaling.
authors.affiliation: ‡From the School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom.
authors.forename: Adil R
authors.identifier: 0000-0003-2163-4910
authors.initials: AR
authors.lastname: Sarhan
authors.affiliation: ‡From the School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom.
authors.forename: Trushar R
authors.identifier: 0000-0003-0627-2923
authors.initials: TR
authors.lastname: Patel
authors.affiliation: ‡From the School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom.
authors.forename: Andrew J
authors.identifier: 0000-0002-4825-0311
authors.initials: AJ
authors.lastname: Creese
authors.affiliation: ‡From the School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Tomlinson
authors.affiliation: ‡From the School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom.
authors.forename: Carina
authors.initials: C
authors.lastname: Hellberg
authors.affiliation: ‡From the School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom.
authors.forename: John K
authors.identifier: 0000-0003-4886-4070
authors.initials: JK
authors.lastname: Heath
authors.affiliation: ‡From the School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom.
authors.forename: Neil A
authors.initials: NA
authors.lastname: Hotchin
authors.affiliation: ‡From the School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom d.cunningham@bham.ac.uk.
authors.forename: Debbie L
authors.identifier: 0000-0001-7776-690X
authors.initials: DL
authors.lastname: Cunningham
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D007553:Isotope Labeling; D020935:MAP Kinase Signaling System; D013058:Mass Spectrometry; D051379:Mice; D000066450:Mouse Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism; D010766:Phosphorylation; D010982:Platelet-Derived Growth Factor / Q000378:metabolism*; D040901:Proteomics / Q000379:methods*; D054623:Receptor-Like Protein Tyrosine Phosphatases, Class 2 / Q000235:genetics* / Q000378:metabolism; D017384:Sequence Deletion; D015398:Signal Transduction; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism*
chemical_list: D010982:Platelet-Derived Growth Factor; C546843:mTOR protein, mouse; D058570:TOR Serine-Threonine Kinases; C000709129:Ptprf protein, mouse; D054623:Receptor-Like Protein Tyrosine Phosphatases, Class 2