title: Backbone resonance assignments for G protein α(i3) subunit in the GTP-bound state.
abstract: Guanine-nucleotide binding proteins (G proteins) act as molecular switches in signaling pathways, by coupling the activation of G protein-coupled receptors (GPCRs) at the cell surface to intracellular responses. In the resting state, G protein forms a heterotrimer, consisting of GDP-bound form of the G protein α subunit (Gα(GDP)) and G protein βγ subunit (Gβγ). Ligand binding to GPCRs promotes the GDP-GTP exchange on Gα, leading to the dissociation of the GTP-bound form of Gα (Gα(GTP)) and Gβγ. Then, Gα(GTP) and Gβγ bind to their downstream effector enzymes or ion channels and regulate their activities, leading to a variety of cellular responses. Finally, Gα hydrolyzes the bound GTP to GDP and returns to the resting state by re-associating with Gβγ. G proteins are classified with four major families based on the amino acid sequences of Gα: i/o, s, q/11, and 12/13. Each family transduces the signaling from different GPCRs to the specific effectors. Here, we established the backbone resonance assignments of human Gα(i3), a member of the i/o family, with a molecular weight of 41 K in complex with a GTP analogue, GTPγS.
authors.affiliation: Graduate School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Tokyo 113-0033, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Mase
authors.forename: Mariko
authors.initials: M
authors.lastname: Yokogawa
authors.forename: Masanori
authors.initials: M
authors.lastname: Osawa
authors.forename: Ichio
authors.initials: I
authors.lastname: Shimada
mesh_terms: D019206:GTP-Binding Protein alpha Subunits, Gi-Go / Q000737:chemistry* / Q000378:metabolism*; D006160:Guanosine Triphosphate / Q000378:metabolism*; D006801:Humans; D019906:Nuclear Magnetic Resonance, Biomolecular; D021122:Protein Subunits / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D021122:Protein Subunits; D006160:Guanosine Triphosphate; C498819:GNAI3 protein, human; D019206:GTP-Binding Protein alpha Subunits, Gi-Go