title: Quantitative phosphoproteomics reveals the protein tyrosine kinase Pyk2 as a central effector of olfactory receptor signaling in prostate cancer cells.
abstract: The prostate-specific G-protein-coupled receptor 1 (PSGR1) is an olfactory receptor specifically expressed in the prostate gland. PSGR1 expression is elevated both in benign prostatic hyperplasia tissue and in prostate cancer. Stimulation of PSGR1 by the odorant β-ionone leads to an increase in the intracellular Ca(2+) concentration, activation of mitogen-activated protein (MAP) kinases and a decrease in prostate cancer cell proliferation. To further extend our knowledge about PSGR1 signaling in prostate cancer cells, we performed a quantitative phosphoproteomics study using stable isotope labeling by amino acids in cell culture and mass spectrometry. We report 51 differentially regulated phosphorylation sites in 24 proteins with functions in cytoskeletal remodeling, signaling and ion transport. Activation of PSGR1 evoked an increase in intracellular pH mediated by the sodium/hydrogen exchanger NHE1. Furthermore, we report the protein tyrosine kinase Pyk2 as a central effector of PSGR1 signaling cascades in LNCaP cells. Our data show that phosphorylation of p38 MAP kinase is triggered by Pyk2. In addition, we confirmed dephosphorylation of the tumor suppressor protein N-myc downstream regulated gene 1 (NDRG1) at Ser330 downstream of Pyk2. Since NDRG1 impacts oncogenic signaling pathways interfering with tumor progression, we suggest that the Pyk2-NDRG1 axis is possibly involved in conveying the anti-proliferative effect of β-ionone in prostate cancer cells. This article is part of a Special Issue entitled: Medical Proteomics.
authors.affiliation: Department of Biochemistry and Functional Proteomics, Faculty of Biology and BIOSS Centre for Biological Signalling Studies, University of Freiburg, Schänzlestr. 1, 79104 Freiburg, Germany.
authors.forename: Heike
authors.initials: H
authors.lastname: Wiese
authors.affiliation: Department of Cell Physiology, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany.
authors.forename: Lian
authors.initials: L
authors.lastname: Gelis
authors.affiliation: Department of Biochemistry and Functional Proteomics, Faculty of Biology and BIOSS Centre for Biological Signalling Studies, University of Freiburg, Schänzlestr. 1, 79104 Freiburg, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Wiese
authors.affiliation: Department of Biochemistry and Functional Proteomics, Faculty of Biology and BIOSS Centre for Biological Signalling Studies, University of Freiburg, Schänzlestr. 1, 79104 Freiburg, Germany.
authors.forename: Christa
authors.initials: C
authors.lastname: Reichenbach
authors.affiliation: Department of Cell Physiology, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany.
authors.forename: Nikolina
authors.initials: N
authors.lastname: Jovancevic
authors.affiliation: Department of Cell Physiology, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Osterloh
authors.affiliation: Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Otto-Hahn-Str. 6b, 44227 Dortmund, Germany.
authors.forename: Helmut E
authors.initials: HE
authors.lastname: Meyer
authors.affiliation: Department of Pharmacology and Toxicology, University of Jena, Drackendorfer Str. 1, 07747 Jena, Germany.
authors.forename: Eva M
authors.initials: EM
authors.lastname: Neuhaus
authors.affiliation: Department of Cell Physiology, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany.
authors.forename: Hanns H
authors.initials: HH
authors.lastname: Hatt
authors.affiliation: Department of Biochemistry and Functional Proteomics, Faculty of Biology and BIOSS Centre for Biological Signalling Studies, University of Freiburg, Schänzlestr. 1, 79104 Freiburg, Germany.
authors.forename: Gerald
authors.initials: G
authors.lastname: Radziwill
authors.affiliation: Department of Biochemistry and Functional Proteomics, Faculty of Biology and BIOSS Centre for Biological Signalling Studies, University of Freiburg, Schänzlestr. 1, 79104 Freiburg, Germany. Electronic address: bettina.warscheid@biologie.uni-freiburg.de.
authors.forename: Bettina
authors.initials: B
authors.lastname: Warscheid
mesh_terms: D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D051418:Focal Adhesion Kinase 2 / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism; D020935:MAP Kinase Signaling System; D008297:Male; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D045792:Norisoprenoids / Q000494:pharmacology; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects / Q000235:genetics; D011471:Prostatic Neoplasms / Q000235:genetics / Q000378:metabolism*; D018035:Receptors, Odorant / Q000235:genetics / Q000378:metabolism*; D048051:p38 Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism; D000099259:N-myc Downstream-Regulated Gene 1 Protein
chemical_list: D018797:Cell Cycle Proteins; D051418:Focal Adhesion Kinase 2; D047908:Intracellular Signaling Peptides and Proteins; D009363:Neoplasm Proteins; D045792:Norisoprenoids; D010750:Phosphoproteins; D018035:Receptors, Odorant; D048051:p38 Mitogen-Activated Protein Kinases; D000099259:N-myc Downstream-Regulated Gene 1 Protein; C417566:OR51E2 protein, human; C008157:beta-ionone
keywords: Olfactory receptor; Phosphoproteomics; Prostate cancer cell; Quantitative mass spectrometry; SILAC; Signal transduction