Quantitative phosphoproteomics reveals the protein tyrosine kinase Pyk2 as a central effector of olfactory receptor signaling in prostate cancer cells

• Published in: Biochimica et biophysica acta 2015-06, Vol.1854 (6), p.632-640
• Main Authors: Wiese, Heike, Gelis, Lian, Wiese, Sebastian, Reichenbach, Christa, Jovancevic, Nikolina, Osterloh, Markus, Meyer, Helmut E., Neuhaus, Eva M., Hatt, Hanns H., Radziwill, Gerald, Warscheid, Bettina
• Format: Article
• Language: English
• Subjects: Cell Cycle Proteins - genetics; Cell Cycle Proteins - metabolism; Cell Line, Tumor; Focal Adhesion Kinase 2 - genetics; Focal Adhesion Kinase 2 - metabolism; Humans; Intracellular Signaling Peptides and Proteins - genetics; Intracellular Signaling Peptides and Proteins - metabolism; Male; MAP Kinase Signaling System; Neoplasm Proteins - genetics; Neoplasm Proteins - metabolism; Norisoprenoids - pharmacology; Olfactory receptor; p38 Mitogen-Activated Protein Kinases - genetics; p38 Mitogen-Activated Protein Kinases - metabolism; Phosphoproteins - genetics; Phosphoproteins - metabolism; Phosphoproteomics; Phosphorylation - drug effects; Phosphorylation - genetics; Prostate cancer cell; Prostatic Neoplasms - genetics; Prostatic Neoplasms - metabolism; Quantitative mass spectrometry; Receptors, Odorant - genetics; Receptors, Odorant - metabolism; Signal transduction; SILAC
• ISSN: 1570-9639; 0006-3002; 1878-1454
• DOI: 10.1016/j.bbapap.2014.09.002

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 Ca2+ 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. [Display omitted] •Study of PSGR1 signaling in prostate cancer cells by quantitative phosphoproteomics.•Activation of PSGR1 with β-ionone leads to an increase in intracellular pH by NHE1.•The protein tyrosine kinase Pyk2 is a central effector of PSGR1 signaling cascades.•Dephosphorylation of NDRG1 at Ser330 occurs downstream of Pyk2.•The Pyk2–NDRG1 axis is proposed to convey the anti-proliferative effect of β-ionone.