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-Structure paper
タイトル | Structures of Ric-8B in complex with Gα protein folding clients reveal isoform specificity mechanisms. |
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ジャーナル・号・ページ | Structure, Vol. 31, Issue 5, Page 553-564.e7, Year 2023 |
掲載日 | 2023年5月4日 |
著者 | Makaía M Papasergi-Scott / Frank E Kwarcinski / Maiya Yu / Ouliana Panova / Ann M Ovrutsky / Georgios Skiniotis / Gregory G Tall / |
PubMed 要旨 | Mammalian Ric-8 proteins act as chaperones to regulate the cellular abundance of heterotrimeric G protein α subunits. The Ric-8A isoform chaperones Gαi/o, Gα12/13, and Gαq/11 subunits, while Ric- ...Mammalian Ric-8 proteins act as chaperones to regulate the cellular abundance of heterotrimeric G protein α subunits. The Ric-8A isoform chaperones Gαi/o, Gα12/13, and Gαq/11 subunits, while Ric-8B acts on Gαs/olf subunits. Here, we determined cryoelectron microscopy (cryo-EM) structures of Ric-8B in complex with Gαs and Gαolf, revealing isoform differences in the relative positioning and contacts between the C-terminal α5 helix of Gα within the concave pocket formed by Ric-8 α-helical repeat elements. Despite the overall architectural similarity with our earlier structures of Ric-8A complexed to Gαq and Gαi1, Ric-8B distinctly accommodates an extended loop found only in Gαs/olf proteins. The structures, along with results from Ric-8 protein thermal stability assays and cell-based Gαolf folding assays, support a requirement for the Gα C-terminal region for binding specificity, and highlight that multiple structural elements impart specificity for Ric-8/G protein binding. |
リンク | Structure / PubMed:36931277 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 2.8 - 3.2 Å |
構造データ | EMDB-28223, PDB-8el7: EMDB-28224, PDB-8el8: |
化合物 | ChemComp-HOH: |
由来 |
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キーワード | SIGNALING PROTEIN / chaperone / armadillo repeat / GEF / complex / Ras |