RT Journal Article SR Electronic T1 Phosphoproteomic Identification of Vasopressin/cAMP/Protein Kinase A–Dependent Signaling in Kidney JF Molecular Pharmacology JO Mol Pharmacol FD American Society for Pharmacology and Experimental Therapeutics SP 358 OP 369 DO 10.1124/mol.120.119602 VO 99 IS 5 A1 Karim Salhadar A1 Allanah Matthews A1 Viswanathan Raghuram A1 Kavee Limbutara A1 Chin-Rang Yang A1 Arnab Datta A1 Chung-Lin Chou A1 Mark A. Knepper YR 2021 UL http://molpharm.aspetjournals.org/content/99/5/358.abstract AB Water excretion by the kidney is regulated by the neurohypophyseal peptide hormone vasopressin through actions in renal collecting duct cells to regulate the water channel protein aquaporin-2. Vasopressin signaling is initiated by binding to a G-protein–coupled receptor called V2R, which signals through heterotrimeric G-protein subunit Gsα, adenylyl cyclase 6, and activation of the cAMP-regulated protein kinase (PKA). Signaling events coupling PKA activation and aquaporin-2 regulation were largely unknown until the advent of modern protein mass spectrometry techniques that allow proteome-wide quantification of protein phosphorylation changes (phosphoproteomics). This short review documents phosphoproteomic findings in collecting duct cells describing the response to V2R-selective vasopressin agonists and antagonists, the response to CRISPR-mediated deletion of PKA, results from in vitro phosphorylation studies using recombinant PKA, the response to the broad-spectrum kinase inhibitor H89 (N-[2-p-bromocinnamylamino-ethyl]-5-isoquinolinesulphonamide), and the responses underlying lithium-induced nephrogenic diabetes insipidus. These phosphoproteomic data sets have been made available online for modeling vasopressin signaling and signaling downstream from other G-protein-coupled receptors.SIGNIFICANCE STATEMENT New developments in protein mass spectrometry are facilitating progress in identification of signaling networks. Using mass spectrometry, it is now possible to identify and quantify thousands of phosphorylation sites in a given cell type (phosphoproteomics). The authors describe the use of phosphoproteomics technology to identify signaling mechanisms downstream from a G-protein-coupled receptor, the vasopressin V2 subtype receptor, and its role of the regulation and dysregulation of water excretion in the kidney. Data from multiple phosphoproteomic data sets are provided as web-based resources.