PKA signaling network-quantitative proteomics and phosphoproteomics

ABSTRACT: Classically, connections within a complex network can be identified through systematically removing its components one at a time and observing the resulting functional changes throughout the network. We applied this concept to identify the signaling network downstream from protein kinase A (PKA) in epithelial cells expressing the Gs-coupled V2 vasopressin receptor. Both genes coding for PKA catalytic subunits (Prkaca and Prkacb) were modified using CRISPR-Cas9 to introduce indels resulting in the absence of detectable PKA catalytic subunit protein (immunoblotting and SILAC-based quantitative protein mass spectrometry). Analysis of multiple PKA double knockout (dKO) lines using SILAC-based quantitative phosphoproteomics showed that phosphorylation sites with decreased phospho-occupancy were dominated by the basophilic motif (R/K)-(R/K)-x-S, consistent with that seen for previously identified PKA targets. Overall, 233 PKA target sites were identified, the majority of which are not annotated as PKA sites in public databases. In addition, we identified a large number of sites with increased phospho-occupancy and the motif x-(S/T)-P, consistent with activation of one or more CMGC family kinases in response to PKA deletion. An unexpected finding was a complete, selective loss of expression of the Aqp2 gene (coding for a kidney-specific water channel) with PKA deletion observed both with quantitative proteomics and RNA-Seq based transcriptomics. Using large-scale data integration techniques, the quantitative proteomic, phosphoproteomic, and RNA-Seq datasets were integrated with prior data from the literature to identify a PKA signaling network that explains most of the cellular physiological responses to vasopressin in the target cells, including the regulation of Aqp2 gene transcription.

OTHER RELATED OMICS DATASETS IN: GSE95009 PRJNA375123 PRJNA375711 PRJNA375712

INSTRUMENT(S): Orbitrap Fusion ETD

ORGANISM(S): Mus Musculus (mouse)

TISSUE(S): Epithelial Cell, Cell Culture

SUBMITTER: CHIN-RANG YANG  

LAB HEAD: Mark A Knepper

PROVIDER: PXD005938 | Pride | 2017-11-23

REPOSITORIES: Pride