title: Phosphoproteomic comparison of Pik3ca and Pten signalling identifies the nucleotidase NT5C as a novel AKT substrate.
abstract: To identify novel effectors and processes regulated by PI3K pathway activation, we performed an unbiased phosphoproteomic screen comparing two common events of PI3K deregulation in cancer: oncogenic Pik3ca mutation (Pik3caH1047R) and deletion of Pten. Using mouse embryonic fibroblast (MEF) models that generate inducible, low-level pathway activation as observed in cancer, we quantified 7566 unique phosphopeptides from 3279 proteins. A number of proteins were found to be differentially-regulated by Pik3caH1047Rand Pten loss, suggesting unique roles for these two events in processes such as vesicular trafficking, DNA damage repair and RNA splicing. We also identified novel PI3K effectors that were commonly-regulated, including putative AKT substrates. Validation of one of these hits, confirmed NT5C (5',3'-Nucleotidase, Cytosolic) as a novel AKT substrate, with an unexpected role in actin cytoskeleton regulation via an interaction with the ARP2/3 complex. This study has produced a comprehensive data resource and identified a new link between PI3K pathway activation and actin regulation.
authors.affiliation: UCL Cancer Institute, Paul O'Gorman Building, University College London, 72 Huntley Street London WC1E 6DD, UK.
authors.forename: Larissa S
authors.initials: LS
authors.lastname: Moniz
authors.affiliation: UCL Cancer Institute, Paul O'Gorman Building, University College London, 72 Huntley Street London WC1E 6DD, UK.
authors.forename: Silvia
authors.initials: S
authors.lastname: Surinova
authors.affiliation: Barts Cancer Institute, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK.
authors.forename: Essam
authors.initials: E
authors.lastname: Ghazaly
authors.affiliation: UCL Cancer Institute, Paul O'Gorman Building, University College London, 72 Huntley Street London WC1E 6DD, UK.
authors.forename: Lorena Gonzalez
authors.initials: LG
authors.lastname: Velasco
authors.affiliation: Barts Cancer Institute, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK.
authors.forename: Syed
authors.initials: S
authors.lastname: Haider
authors.affiliation: Barts Cancer Institute, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Rodríguez-Prados
authors.affiliation: UCL Cancer Institute, Paul O'Gorman Building, University College London, 72 Huntley Street London WC1E 6DD, UK.
authors.forename: Inma M
authors.initials: IM
authors.lastname: Berenjeno
authors.affiliation: Barts Cancer Institute, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK.
authors.forename: Claude
authors.initials: C
authors.lastname: Chelala
authors.affiliation: UCL Cancer Institute, Paul O'Gorman Building, University College London, 72 Huntley Street London WC1E 6DD, UK.
authors.forename: Bart
authors.initials: B
authors.lastname: Vanhaesebroeck
mesh_terms: D015720:5'-Nucleotidase / Q000378:metabolism*; D000818:Animals; D002478:Cells, Cultured; D058534:Class I Phosphatidylinositol 3-Kinases; D017353:Gene Deletion; D005786:Gene Expression Regulation; D051379:Mice; D000066450:Mouse Embryonic Stem Cells; D009154:Mutation; D051059:PTEN Phosphohydrolase / Q000235:genetics* / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics* / Q000378:metabolism; D010750:Phosphoproteins / Q000032:analysis*; D040901:Proteomics / Q000379:methods*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D015720:5'-Nucleotidase; D058534:Class I Phosphatidylinositol 3-Kinases; D051059:PTEN Phosphohydrolase; D019869:Phosphatidylinositol 3-Kinases; D010750:Phosphoproteins; D051057:Proto-Oncogene Proteins c-akt; C546639:Pik3ca protein, mouse; C487757:Pten protein, mouse