Snapshot of Activated G Proteins at the Membrane: The Gαq-GRK2-Gβγ Complex
Abstract
G protein-coupled receptor kinase 2 (GRK2) plays a key role in the desensitization of G protein-coupled receptor signaling by phosphorylating activated heptahelical receptors and by sequestering heterotrimeric G proteins. We report the atomic structure of GRK2 in complex with Gαq and Gβγ, in which the activated Gα subunit of Gq is fully dissociated from Gβγ and dramatically reoriented from its position in the inactive Gαβγ heterotrimer. Gαq forms an effector-like interaction with the GRK2 regulator of G protein signaling (RGS) homology domain that is distinct from and does not overlap with that used to bind RGS proteins such as RGS4.
- Publication:
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Science
- Pub Date:
- December 2005
- DOI:
- 10.1126/science.1118890
- Bibcode:
- 2005Sci...310.1686T
- Keywords:
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- BIOCHEM