title: Activation of diverse signalling pathways by oncogenic PIK3CA mutations.
abstract: The PIK3CA gene is frequently mutated in human cancers. Here we carry out a SILAC-based quantitative phosphoproteomic analysis using isogenic knockin cell lines containing 'driver' oncogenic mutations of PIK3CA to dissect the signalling mechanisms responsible for oncogenic phenotypes induced by mutant PIK3CA. From 8,075 unique phosphopeptides identified, we observe that aberrant activation of PI3K pathway leads to increased phosphorylation of a surprisingly wide variety of kinases and downstream signalling networks. Here, by integrating phosphoproteomic data with human protein microarray-based AKT1 kinase assays, we discover and validate six novel AKT1 substrates, including cortactin. Through mutagenesis studies, we demonstrate that phosphorylation of cortactin by AKT1 is important for mutant PI3K-enhanced cell migration and invasion. Our study describes a quantitative and global approach for identifying mutation-specific signalling events and for discovering novel signalling molecules as readouts of pathway activation or potential therapeutic targets.
authors.affiliation: McKusick-Nathans Institute of Genetic Medicine and Department of Biological Chemistry, Johns Hopkins University School of Medicine, 733 North Broadway, BRB 527, Baltimore, Maryland 21205, USA.
authors.forename: Xinyan
authors.initials: X
authors.lastname: Wu
authors.affiliation: 1] Institute of Bioinformatics, International Tech Park, Bangalore 560066, India [2] Amrita School of Biotechnology, Amrita Vishwa Vidyapeetham, Kollam 690 525, India.
authors.forename: Santosh
authors.initials: S
authors.lastname: Renuse
authors.affiliation: 1] Institute of Bioinformatics, International Tech Park, Bangalore 560066, India [2] Manipal University, Manipal 576104, India.
authors.forename: Nandini A
authors.initials: NA
authors.lastname: Sahasrabuddhe
authors.affiliation: McKusick-Nathans Institute of Genetic Medicine and Department of Biological Chemistry, Johns Hopkins University School of Medicine, 733 North Broadway, BRB 527, Baltimore, Maryland 21205, USA.
authors.forename: Muhammad Saddiq
authors.initials: MS
authors.lastname: Zahari
authors.affiliation: McKusick-Nathans Institute of Genetic Medicine and Department of Biological Chemistry, Johns Hopkins University School of Medicine, 733 North Broadway, BRB 527, Baltimore, Maryland 21205, USA.
authors.forename: Raghothama
authors.initials: R
authors.lastname: Chaerkady
authors.affiliation: McKusick-Nathans Institute of Genetic Medicine and Department of Biological Chemistry, Johns Hopkins University School of Medicine, 733 North Broadway, BRB 527, Baltimore, Maryland 21205, USA.
authors.forename: Min-Sik
authors.initials: MS
authors.lastname: Kim
authors.affiliation: Institute of Bioinformatics, International Tech Park, Bangalore 560066, India.
authors.forename: Raja S
authors.initials: RS
authors.lastname: Nirujogi
authors.affiliation: McKusick-Nathans Institute of Genetic Medicine and Department of Biological Chemistry, Johns Hopkins University School of Medicine, 733 North Broadway, BRB 527, Baltimore, Maryland 21205, USA.
authors.forename: Morassa
authors.initials: M
authors.lastname: Mohseni
authors.affiliation: 1] Institute of Bioinformatics, International Tech Park, Bangalore 560066, India [2] Manipal University, Manipal 576104, India.
authors.forename: Praveen
authors.initials: P
authors.lastname: Kumar
authors.affiliation: Institute of Bioinformatics, International Tech Park, Bangalore 560066, India.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Raju
authors.affiliation: McKusick-Nathans Institute of Genetic Medicine and Department of Biological Chemistry, Johns Hopkins University School of Medicine, 733 North Broadway, BRB 527, Baltimore, Maryland 21205, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhong
authors.affiliation: Ludwig Center and Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, USA.
authors.forename: Jian
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, USA.
authors.forename: Johnathan
authors.initials: J
authors.lastname: Neiswinger
authors.affiliation: Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, USA.
authors.forename: Jun-Seop
authors.initials: JS
authors.lastname: Jeong
authors.affiliation: Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Newman
authors.affiliation: Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
authors.forename: Maureen A
authors.initials: MA
authors.lastname: Powers
authors.affiliation: Institute of Bioinformatics, International Tech Park, Bangalore 560066, India.
authors.forename: Babu Lal
authors.initials: BL
authors.lastname: Somani
authors.affiliation: Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, USA.
authors.forename: Edward
authors.initials: E
authors.lastname: Gabrielson
authors.affiliation: Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, USA.
authors.forename: Saraswati
authors.initials: S
authors.lastname: Sukumar
authors.affiliation: Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, USA.
authors.forename: Vered
authors.initials: V
authors.lastname: Stearns
authors.affiliation: Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, USA.
authors.forename: Jiang
authors.initials: J
authors.lastname: Qian
authors.affiliation: Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, USA.
authors.forename: Heng
authors.initials: H
authors.lastname: Zhu
authors.affiliation: Ludwig Center and Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, USA.
authors.forename: Bert
authors.initials: B
authors.lastname: Vogelstein
authors.affiliation: Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, USA.
authors.forename: Ben Ho
authors.initials: BH
authors.lastname: Park
authors.affiliation: 1] McKusick-Nathans Institute of Genetic Medicine and Department of Biological Chemistry, Johns Hopkins University School of Medicine, 733 North Broadway, BRB 527, Baltimore, Maryland 21205, USA [2] Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, USA [3] Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, USA.
authors.forename: Akhilesh
authors.initials: A
authors.lastname: Pandey
mesh_terms: D002853:Chromatography, Liquid; D058534:Class I Phosphatidylinositol 3-Kinases; D051356:Cortactin / Q000378:metabolism*; D017931:DNA Primers / Q000235:genetics; D005455:Fluorescent Antibody Technique; D055879:Gene Knock-In Techniques; D006801:Humans; D015151:Immunoblotting; D047468:Immunoprecipitation; D016297:Mutagenesis, Site-Directed; D009154:Mutation / Q000235:genetics; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics*; D010750:Phosphoproteins / Q000235:genetics*; D040901:Proteomics; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology*; D053719:Tandem Mass Spectrometry
chemical_list: D051356:Cortactin; D017931:DNA Primers; D010750:Phosphoproteins; D034741:RNA, Small Interfering; D019869:Phosphatidylinositol 3-Kinases; D058534:Class I Phosphatidylinositol 3-Kinases; C484760:PIK3CA protein, human; C494918:AKT1 protein, human; D051057:Proto-Oncogene Proteins c-akt