Illuminating G-Protein-Coupling Selectivity of GPCRs.

Inoue, Asuka; Raimondi, Francesco; Kadji, Francois Marie Ngako; Singh, Gurdeep; Kishi, Takayuki; Uwamizu, Akiharu; Ono, Yuki; Shinjo, Yuji et al. · Cell · 2019

basic_science · Level V

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Abstract

Heterotrimetic G proteins consist of four subfamilies (G<sub>s</sub>, G<sub>i/o</sub>, G<sub>q/11</sub>, and G<sub>12/13</sub>) that mediate signaling via G-protein-coupled receptors (GPCRs), principally by receptors binding Gα C termini. G-protein-coupling profiles govern GPCR-induced cellular responses, yet receptor sequence selectivity determinants remain elusive. Here, we systematically quantified ligand-induced interactions between 148 GPCRs and all 11 unique Gα subunit C termini. For each receptor, we probed chimeric Gα subunit activation via a transforming growth factor-α (TGF-α) shedding response in HEK293 cells lacking endogenous G<sub>q/11</sub> and G<sub>12/13</sub> proteins, and complemented G-protein-coupling profiles through a NanoBiT-G-protein dissociation assay. Interrogation of the dataset identified sequence-based coupling specificity features, inside and outside the transmembrane domain, which we used to develop a coupling predictor that outperforms previous methods. We used the predictor to engineer designer GPCRs selectively coupled to G<sub>12</sub>. This dataset of fine-tuned signaling mechanisms for diverse GPCRs is a valuable resource for research in GPCR signaling.

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