9epr
Cryo-EM Structure of Jumping Spider Rhodopsin-1 bound to a Gi heterotrimerCryo-EM Structure of Jumping Spider Rhodopsin-1 bound to a Gi heterotrimer
Structural highlights
FunctionGNAI1_HUMAN Guanine nucleotide-binding proteins (G proteins) are involved as modulators or transducers in various transmembrane signaling systems. The G(i) proteins are involved in hormonal regulation of adenylate cyclase: they inhibit the cyclase in response to beta-adrenergic stimuli. The inactive GDP-bound form prevents the association of RGS14 with centrosomes and is required for the translocation of RGS14 from the cytoplasm to the plasma membrane. May play a role in cell division.[1] [2] Publication Abstract from PubMedOpsins are G protein-coupled receptors (GPCRs) that have evolved to detect light stimuli and initiate intracellular signaling cascades. Their role as signal transducers is critical to light perception across the animal kingdom. Opsins covalently bind to the chromophore 11-cis retinal, which isomerizes to the all-trans isomer upon photon absorption, causing conformational changes that result in receptor activation. Monostable opsins, responsible for vision in vertebrates, release the chromophore after activation and must bind another retinal molecule to remain functional. In contrast, bistable opsins, responsible for non-visual light perception in vertebrates and for vision in invertebrates, absorb a second photon in the active state to return the chromophore and protein to the inactive state. Structures of bistable opsins in the activated state have proven elusive, limiting our understanding of how they function as bidirectional photoswitches. Here we present active state structures of a bistable opsin, jumping spider rhodopsin isoform-1 (JSR1), in complex with its downstream signaling partners, the G(i) and G(q) heterotrimers. These structures elucidate key differences in the activation mechanisms between monostable and bistable opsins, offering essential insights for the rational engineering of bistable opsins into diverse optogenetic tools to control G protein signaling pathways. Active state structures of a bistable visual opsin bound to G proteins.,Tejero O, Pamula F, Koyanagi M, Nagata T, Afanasyev P, Das I, Deupi X, Sheves M, Terakita A, Schertler GFX, Rodrigues MJ, Tsai CJ Nat Commun. 2024 Oct 16;15(1):8928. doi: 10.1038/s41467-024-53208-2. PMID:39414813[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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