Interactome Analysis Reveals Regulator of G Protein Signaling 14 (RGS14) is a Novel Calcium/Calmodulin (Ca2+/CaM) and CaM Kinase II (CaMKII) Binding Partner

• Type of Material: Article
• Authors: Paul R. Evans, Emory University; Kyle J. Gerber, Emory University; Eric B Dammer, Emory University; Duc M. Duong, Emory University; Devrishi Goswami, Scripps Research Institute; Daniel J. Lustberg, National Institute of Environmental Health Sciences; Juan Zou, Georgia State University; Jenny J. Yang, Georgia State University; Serena M. Dudek, National Institute of Environmental Health Sciences; Patrick R. Griffin, Scripps Research Institute; Nicholas Seyfried, Emory University; John R Hepler, Emory University
• Language: English
• Date: 2018-04-01
• Publisher: American Chemical Society
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2018 American Chemical Society.
• Final Published Version (URL): http://dx.doi.org/10.1021/acs.jproteome.8b00027
• Title of Journal or Parent Work: Journal of Proteome Research
• ISSN: 1535-3893
• Volume: 17
• Issue: 4
• Start Page: 1700
• End Page: 1711
• Grant/Funding Information: J.R.H. was supported by grants from the National Institutes of Health/National Institute of Neurological Disorders and Stroke (5R01NS37112 and 1R21NS074975).; Research reported in this publication was supported in part by the Emory Neuroscience NINDS Core Facilities; and NIH/NIND Sunder award number P30NS055077.; P.R.E. was supported by a predoctoral fellowship from the National Institutes of Health/National Institute of Neurological Disorders and Stroke (1F31NS086174).; S.M.D. was supported by the Intramural Research Program of the National Institute of Environmental Health Sciences, National Institutes of Health (Z01ES100221).
• Keywords: CALMODULIN; G-ALPHA(I); AREA CA2; LARGE GENE LISTS; HUMAN BRAIN; Regulator of G Protein Signaling 14 (RGS14); synapse; calcium (Ca2+); interactome; MEMORY; SYNAPTIC PLASTICITY; LONG-TERM POTENTIATION; GTPASE-ACTIVATING PROTEIN; Ca2+/calmodulin-dependent protein kinase II (CaMKII); VASOPRESSIN 1B RECEPTOR; calmodulin (CaM); Biochemistry & Molecular Biology; Science & Technology; hippocampus CA2; Biochemical Research Methods; long-term potentiation (LTP); Life Sciences & Biomedicine; learning and memory; synaptic plasticity
• Research Categories: Chemistry, Biochemistry; Health Sciences, Pharmacology; Biology, Molecular

Abstract

Regulator of G Protein Signaling 14 (RGS14) is a complex scaffolding protein that integrates G protein and MAPK signaling pathways. In the adult mouse brain, RGS14 is predominantly expressed in hippocampal CA2 neurons where it naturally inhibits synaptic plasticity and hippocampus-dependent learning and memory. However, the signaling proteins that RGS14 natively engages to regulate plasticity are unknown. Here, we show that RGS14 exists in a high-molecular-weight protein complex in brain. To identify RGS14 neuronal interacting partners, endogenous RGS14 immunoprecipitated from mouse brain was subjected to mass spectrometry and proteomic analysis. We find that RGS14 interacts with key postsynaptic proteins that regulate plasticity. Gene ontology analysis reveals the most enriched RGS14 interactors have functional roles in actin-binding, calmodulin(CaM)-binding, and CaM-dependent protein kinase (CaMK) activity. We validate these findings using biochemical assays that identify interactions with two previously unknown binding partners. We report that RGS14 directly interacts with Ca 2+ /CaM and is phosphorylated by CaMKII in vitro. Lastly, we detect that RGS14 associates with CaMKII and CaM in hippocampal CA2 neurons. Taken together, these findings demonstrate that RGS14 is a novel CaM effector and CaMKII phosphorylation substrate thereby providing new insight into mechanisms by which RGS14 controls plasticity in CA2 neurons.