View source for 8wg8


==Cryo-EM structures of peptide free and Gs-coupled GCGR==
<StructureSection load='8wg8' size='340' side='right'caption='[[8wg8]], [[Resolution|resolution]] 2.71&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[8wg8]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Bos_taurus Bos taurus], [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens], [https://en.wikipedia.org/wiki/Rattus_norvegicus Rattus norvegicus], [https://en.wikipedia.org/wiki/Spodoptera_frugiperda Spodoptera frugiperda] and [https://en.wikipedia.org/wiki/Synthetic_construct Synthetic construct]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8WG8 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8WG8 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 2.71&#8491;</td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=8wg8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8wg8 OCA], [https://pdbe.org/8wg8 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8wg8 RCSB], [https://www.ebi.ac.uk/pdbsum/8wg8 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8wg8 ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/GNAS2_HUMAN GNAS2_HUMAN] Pseudopseudohypoparathyroidism;Pseudohypoparathyroidism type 1A;Progressive osseous heteroplasia;Polyostotic fibrous dysplasia;Monostotic fibrous dysplasia;Pseudohypoparathyroidism type 1C;Pseudohypoparathyroidism type 1B;McCune-Albright syndrome. The disease is caused by mutations affecting the gene represented in this entry.  The disease is caused by mutations affecting the gene represented in this entry.  The disease is caused by mutations affecting the gene represented in this entry.  The disease is caused by mutations affecting the gene represented in this entry.  The disease is caused by mutations affecting the gene represented in this entry.  The disease is caused by mutations affecting the gene represented in this entry.  The disease is caused by mutations affecting the gene represented in this entry. Most affected individuals have defects in methylation of the gene. In some cases microdeletions involving the STX16 appear to cause loss of methylation at exon A/B of GNAS, resulting in PHP1B. Paternal uniparental isodisomy have also been observed.  The disease is caused by mutations affecting the gene represented in this entry.  The disease is caused by mutations affecting the gene represented in this entry.
== Function ==
[https://www.uniprot.org/uniprot/GNAS2_HUMAN GNAS2_HUMAN] Guanine nucleotide-binding proteins (G proteins) function as transducers in numerous signaling pathways controlled by G protein-coupled receptors (GPCRs) (PubMed:17110384). Signaling involves the activation of adenylyl cyclases, resulting in increased levels of the signaling molecule cAMP (PubMed:26206488, PubMed:8702665). GNAS functions downstream of several GPCRs, including beta-adrenergic receptors (PubMed:21488135). Stimulates the Ras signaling pathway via RAPGEF2 (PubMed:12391161).<ref>PMID:12391161</ref> <ref>PMID:17110384</ref> <ref>PMID:21488135</ref> <ref>PMID:26206488</ref> <ref>PMID:8702665</ref> [https://www.uniprot.org/uniprot/GNAI1_HUMAN GNAI1_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.<ref>PMID:17635935</ref> <ref>PMID:17264214</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Class B1 G protein-coupled receptors (GPCRs) are important regulators of many physiological functions such as glucose homeostasis, which is mainly mediated by three peptide hormones, i.e., glucagon-like peptide-1 (GLP-1), glucagon (GCG), and glucose-dependent insulinotropic polypeptide (GIP). They trigger a cascade of signaling events leading to the formation of an active agonist-receptor-G protein complex. However, intracellular signal transducers can also activate the receptor independent of extracellular stimuli, suggesting an intrinsic role of G proteins in this process. Here, we report cryo-electron microscopy structures of the human GLP-1 receptor (GLP-1R), GCG receptor (GCGR), and GIP receptor (GIPR) in complex with G(s) proteins without the presence of cognate ligands. These ligand-free complexes share a similar intracellular architecture to those bound by endogenous peptides, in which, the G(s) protein alone directly opens the intracellular binding cavity and rewires the extracellular orthosteric pocket to stabilize the receptor in a state unseen before. While the peptide-binding site is partially occupied by the inward folded transmembrane helix 6 (TM6)-extracellular loop 3 (ECL3) juncture of GIPR or a segment of GCGR ECL2, the extracellular portion of GLP-1R adopts a conformation close to the active state. Our findings offer valuable insights into the distinct activation mechanisms of these three important receptors. It is possible that in the absence of a ligand, the intracellular half of transmembrane domain is mobilized with the help of G(s) protein, which in turn rearranges the extracellular half to form a transitional conformation, facilitating the entry of the peptide N-terminus.

Molecular features of the ligand-free GLP-1R, GCGR and GIPR in complex with G(s) proteins.,Cong Z, Zhao F, Li Y, Luo G, Mai Y, Chen X, Chen Y, Lin S, Cai X, Zhou Q, Yang D, Wang MW Cell Discov. 2024 Feb 13;10(1):18. doi: 10.1038/s41421-024-00649-0. PMID:38346960<ref>PMID:38346960</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 8wg8" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Bos taurus]]
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Rattus norvegicus]]
[[Category: Spodoptera frugiperda]]
[[Category: Synthetic construct]]
[[Category: Cong ZT]]
[[Category: Li Y]]
[[Category: Luo G]]
[[Category: Wang MW]]
[[Category: Yang DH]]
[[Category: Zhao FH]]
[[Category: Zhou QT]]