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Modulation of Synaptic transmission: Quantitative analysis of Gβγ specificity to adrenergic α 2a receptor and SNARE.
Author(s) -
Yim Yun Young,
Betke Katherine,
McDonald W. Hayes,
Gilsbach Ralf,
Chen Yunjia,
Hyde Karren,
Wang Qin,
Hein Lutz,
Schey Kevin,
Hamm Heidi
Publication year - 2018
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2018.32.1_supplement.557.6
Subject(s) - microbiology and biotechnology , neurotransmission , g protein coupled receptor , gq alpha subunit , g protein , receptor , neurotransmitter , chemistry , immunoprecipitation , signal transduction , biology , biochemistry , gene
Modulation of neurotransmitter exocytosis by activated G i/o coupled G‐protein coupled receptors (GPCRs) is a universal regulatory mechanism used both to avoid overstimulation and to influence circuitry. One of the known modulation mechanisms is Gβγ interaction with soluble N‐ethylmaleimide‐sensitive factor attachment protein receptor (SNARE). There are 5 Gβ and 12 Gγ subunits, but specific Gβγs activated by a given GPCR and the specificity to effectors in vivo are not known. Presynaptic α 2a ‐adrenergic receptors (α 2a ARs) in both adrenergic (auto α 2a ARs) and non‐adrenergic neurons (hetero α 2a ARs) inhibit neurotransmitter release and affect various physiological functions such as anesthetic sparing and working memory enhancement. With a quantitative MRM proteomic analysis of neuronal Gβ and Gγ subunits to detect neuronal Gβ and Gγ subunits, several mouse models including transgenic Flag‐α 2a ARs, knock‐in HA‐α 2a ARs, and other biochemical techniques such as co‐immunoprecipitation, we investigate the specificity of Gβ and Gγ subunits to α 2a ARs in both adrenergic(auto α 2a ARs) and non‐adrenergic neurons (hetero α 2a ARs), and SNARE in presence of epinephrine. Gβ 2, Gγ 2 , Gγ 3 , and Gγ 4 preferentially interact with activated auto α 2a ARs while Gβ 4 and Gγ 12 preferentially interact with activated hetero α 2a ARs. We also detect a subset of Gβ and Gγ subunits interacting with SNARE upon α 2a ARs activation. Further understanding of Gβγ specificity on its downstream signaling, especially Gβγ‐SNARE interaction, offers new insights into the normal functioning of the brain and lead to an identification of potential pathophysiological states in which the Gβγ‐SNARE interaction may be dysregulated. These studies yield additional insights into G i/o ‐coupled GPCR‐mediated regulation of exocytosis. Support or Funding Information This work was supported by the National Institutes of Health (EY10291, MH101679, DK109204, and T32 GM07628). This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .