A neurodevelopmental disorder mutation locks G proteins in the transitory pre-activated state.

Autor: Knight KM; Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.; Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, University of Florida, Jupiter, FL, USA., Krumm BE; Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA., Kapolka NJ; Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA., Ludlam WG; Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, University of Florida, Jupiter, FL, USA., Cui M; Department of Pharmaceutical Sciences Northeastern University, Boston, MA, USA., Mani S; Department of Pharmaceutical Sciences Northeastern University, Boston, MA, USA., Prytkova I; Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA., Obarow EG; Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA., Lefevre TJ; Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA., Wei W; Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, CA, USA., Ma N; Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, CA, USA., Huang XP; Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA., Fay JF; Department of Biochemistry and Molecular Biology, School of Medicine, University of Maryland, Baltimore, Baltimore, MD, USA., Vaidehi N; Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, CA, USA., Smrcka AV; Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA., Slesinger PA; Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA., Logothetis DE; Department of Pharmaceutical Sciences Northeastern University, Boston, MA, USA., Martemyanov KA; Department of Neuroscience, The Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology, University of Florida, Jupiter, FL, USA., Roth BL; Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA., Dohlman HG; Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. hdohlman@med.unc.edu.
Jazyk: angličtina
Zdroj: Nature communications [Nat Commun] 2024 Aug 05; Vol. 15 (1), pp. 6643. Date of Electronic Publication: 2024 Aug 05.
DOI: 10.1038/s41467-024-50964-z
Abstrakt: Many neurotransmitter receptors activate G proteins through exchange of GDP for GTP. The intermediate nucleotide-free state has eluded characterization, due largely to its inherent instability. Here we characterize a G protein variant associated with a rare neurological disorder in humans. Gα o K46E has a charge reversal that clashes with the phosphate groups of GDP and GTP. As anticipated, the purified protein binds poorly to guanine nucleotides yet retains wild-type affinity for G protein βγ subunits. In cells with physiological concentrations of nucleotide, Gα o K46E forms a stable complex with receptors and Gβγ, impeding effector activation. Further, we demonstrate that the mutant can be easily purified in complex with dopamine-bound D2 receptors, and use cryo-electron microscopy to determine the structure, including both domains of Gα o , without nucleotide or stabilizing nanobodies. These findings reveal the molecular basis for the first committed step of G protein activation, establish a mechanistic basis for a neurological disorder, provide a simplified strategy to determine receptor-G protein structures, and a method to detect high affinity agonist binding in cells.
(© 2024. The Author(s).)
Databáze: MEDLINE
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