| Autor: |
Kevin M. Knight, Brian E. Krumm, Nicholas J. Kapolka, W. Grant Ludlam, Meng Cui, Sepehr Mani, Iya Prytkova, Elizabeth G. Obarow, Tyler J. Lefevre, Wenyuan Wei, Ning Ma, Xi-Ping Huang, Jonathan F. Fay, Nagarajan Vaidehi, Alan V. Smrcka, Paul A. Slesinger, Diomedes E. Logothetis, Kirill A. Martemyanov, Bryan L. Roth, Henrik G. Dohlman |
| Jazyk: |
angličtina |
| Rok vydání: |
2024 |
| Předmět: |
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| Zdroj: |
Nature Communications, Vol 15, Iss 1, Pp 1-18 (2024) |
| Druh dokumentu: |
article |
| ISSN: |
2041-1723 |
| DOI: |
10.1038/s41467-024-50964-z |
| Popis: |
Abstract 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. Gαo 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, Gαo 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 Gαo, 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. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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