6cmo
From Proteopedia
Rhodopsin-Gi complex
Structural highlights
DiseaseOPSD_HUMAN Congenital stationary night blindness;Retinitis punctata albescens;Retinitis pigmentosa. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. FunctionC562_ECOLX Electron-transport protein of unknown function.OPSD_HUMAN Photoreceptor required for image-forming vision at low light intensity (PubMed:7846071, PubMed:8107847). Required for photoreceptor cell viability after birth (PubMed:12566452, PubMed:2215617). Light-induced isomerization of the chromophore 11-cis-retinal to all-trans-retinal triggers a conformational change that activates signaling via G-proteins (PubMed:26200343, PubMed:28524165, PubMed:28753425, PubMed:8107847). Subsequent receptor phosphorylation mediates displacement of the bound G-protein alpha subunit by the arrestin SAG and terminates signaling (PubMed:26200343, PubMed:28524165).[1] [2] [3] [4] [5] [6] [7] Publication Abstract from PubMedG-protein-coupled receptors comprise the largest family of mammalian transmembrane receptors. They mediate numerous cellular pathways by coupling with downstream signalling transducers, including the hetrotrimeric G proteins Gs (stimulatory) and Gi (inhibitory) and several arrestin proteins. The structural mechanisms that define how G-protein-coupled receptors selectively couple to a specific type of G protein or arrestin remain unknown. Here, using cryo-electron microscopy, we show that the major interactions between activated rhodopsin and Gi are mediated by the C-terminal helix of the Gi alpha-subunit, which is wedged into the cytoplasmic cavity of the transmembrane helix bundle and directly contacts the amino terminus of helix 8 of rhodopsin. Structural comparisons of inactive, Gi-bound and arrestin-bound forms of rhodopsin with inactive and Gs-bound forms of the beta2-adrenergic receptor provide a foundation to understand the unique structural signatures that are associated with the recognition of Gs, Gi and arrestin by activated G-protein-coupled receptors. Cryo-EM structure of human rhodopsin bound to an inhibitory G protein.,Kang Y, Kuybeda O, de Waal PW, Mukherjee S, Van Eps N, Dutka P, Zhou XE, Bartesaghi A, Erramilli S, Morizumi T, Gu X, Yin Y, Liu P, Jiang Y, Meng X, Zhao G, Melcher K, Ernst OP, Kossiakoff AA, Subramaniam S, Xu HE Nature. 2018 Jun;558(7711):553-558. doi: 10.1038/s41586-018-0215-y. Epub 2018 Jun, 13. PMID:29899450[8] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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Categories: Bos taurus | Escherichia coli | Homo sapiens | Large Structures | Rattus norvegicus | Synthetic construct | Bartesaghi A | Dutka P | Earnst OP | Erramilli S | Gu X | Jiang Y | Kang Y | Kossiakoff AA | Kuybeda O | Liu P | Melcher K | Meng X | Morizumi T | Mukherjee S | Subramaniam S | Van Eps N | Xu HE | Yin Y | Zhao G | Zhou XE | De Waal PW