8zd1
From Proteopedia
Cryo-EM structure of the xGPR4-Gs complex in pH6.2
Structural highlights
DiseaseGNAS2_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. FunctionGNAS2_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).[1] [2] [3] [4] [5] Publication Abstract from PubMedAnimals have evolved pH-sensing membrane receptors, such as G-protein-coupled receptor 4 (GPR4), to monitor pH changes related to their physiology and generate adaptive reactions. However, the evolutionary trajectory and structural mechanism of proton sensing by GPR4 remain unresolved. Here, we observed a positive correlation between the optimal pH of GPR4 activity and the blood pH range across different species. By solving 7-cryoelectron microscopy (cryo-EM) structures of Xenopus tropicalis GPR4 (xtGPR4) and Mus musculus GPR4 (mmGPR4) under varying pH conditions, we identified that protonation of H(ECL2-45.47) and H(7.36) enabled polar network establishment and tighter association between the extracellular loop 2 (ECL2) and 7 transmembrane (7TM) domain, as well as a conserved propagating path, which are common mechanisms underlying protonation-induced GPR4 activation across different species. Moreover, protonation of distinct extracellular H(ECL2-45.41) contributed to the more acidic optimal pH range of xtGPR4. Overall, our study revealed common and distinct mechanisms of proton sensing by GPR4, from a structural, functional, and evolutionary perspective. Evolutionary study and structural basis of proton sensing by Mus GPR4 and Xenopus GPR4.,Wen X, Shang P, Chen H, Guo L, Rong N, Jiang X, Li X, Liu J, Yang G, Zhang J, Zhu K, Meng Q, He X, Wang Z, Liu Z, Cheng H, Zheng Y, Zhang B, Pang J, Liu Z, Xiao P, Chen Y, Liu L, Luo F, Yu X, Yi F, Zhang P, Yang F, Deng C, Sun JP Cell. 2025 Feb 6;188(3):653-670.e24. doi: 10.1016/j.cell.2024.12.001. Epub 2025 , Jan 2. PMID:39753131[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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