Journal article
Inhibitory Signaling to Ion Channels in Hippocampal Neurons Is Differentially Regulated by Alternative Macromolecular Complexes of RGS7
The Journal of neuroscience, Vol.38(46), pp.10002-10015
11/14/2018
DOI: 10.1523/JNEUROSCI.1378-18.2018
PMCID: PMC6234300
PMID: 30315127
Abstract
The neuromodulatory effects of GABA on pyramidal neurons are mediated by GABA
receptors (GABA
Rs) that signal via a conserved G-protein-coupled pathway. Two prominent effectors regulated by GABA
Rs include G-protein inwardly rectifying K
(GIRK) and P/Q/N type voltage-gated Ca
(Ca
2) ion channels that control excitability and synaptic output of these neurons, respectively. Regulator of G-protein signaling 7 (RGS7) has been shown to control GABA
effects, yet the specificity of its impacts on effector channels and underlying molecular mechanisms is poorly understood. In this study, we show that hippocampal RGS7 forms two distinct complexes with alternative subunit configuration bound to either membrane protein R7BP (RGS7 binding protein) or orphan receptor GPR158. Quantitative biochemical experiments show that both complexes account for targeting nearly the entire pool of RGS7 to the plasma membrane. We analyzed the effect of genetic elimination in mice of both sexes and overexpression of various components of RGS7 complex by patch-clamp electrophysiology in cultured neurons and brain slices. We report that RGS7 prominently regulates GABA
R signaling to Ca
2, in addition to its known involvement in modulating GIRK. Strikingly, only complexes containing R7BP, but not GPR158, accelerated the kinetics of both GIRK and Ca
2 modulation by GABA
Rs. In contrast, GPR158 overexpression exerted the opposite effect and inhibited RGS7-assisted temporal modulation of GIRK and Ca
2 by GABA. Collectively, our data reveal mechanisms by which distinctly composed macromolecular complexes modulate the activity of key ion channels that mediate the inhibitory effects of GABA on hippocampal CA1 pyramidal neurons.
This study identifies the contributions of distinct macromolecular complexes containing a major G-protein regulator to controlling key ion channel function in hippocampal neurons with implications for understanding molecular mechanisms underlying synaptic plasticity, learning, and memory.
Details
- Title: Subtitle
- Inhibitory Signaling to Ion Channels in Hippocampal Neurons Is Differentially Regulated by Alternative Macromolecular Complexes of RGS7
- Creators
- Olga I Ostrovskaya - Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida 33458Cesare Orlandi - Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida 33458Ana Fajardo-Serrano - Departamento de Ciencias Médicas, Facultad de Medicina, Universidad de Castilla-La Mancha, 02006 Albacete, Spain, andSamuel M Young Jr - Departments of Anatomy and Cell Biology and Department of Otolaryngology, Iowa Neuroscience Institute, and Aging Mind Brain Initiative, University of Iowa, Iowa City, Iowa 52242Rafael Lujan - Departamento de Ciencias Médicas, Facultad de Medicina, Universidad de Castilla-La Mancha, 02006 Albacete, Spain, andKirill A Martemyanov - Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida 33458, kirill@scripps.edu
- Resource Type
- Journal article
- Publication Details
- The Journal of neuroscience, Vol.38(46), pp.10002-10015
- Publisher
- United States
- DOI
- 10.1523/JNEUROSCI.1378-18.2018
- PMID
- 30315127
- PMCID
- PMC6234300
- ISSN
- 0270-6474
- eISSN
- 1529-2401
- Grant note
- R01 DC014093 / NIDCD NIH HHS K02 DA026405 / NIDA NIH HHS R01 DA021743 / NIDA NIH HHS R01 MH105482 / NIMH NIH HHS
- Language
- English
- Date published
- 11/14/2018
- Academic Unit
- Anatomy and Cell Biology; Iowa Neuroscience Institute; Otolaryngology
- Record Identifier
- 9984025446502771
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