8fu6
From Proteopedia
GCGR-Gs complex in the presence of RAMP2
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 PubMedReceptor activity-modifying proteins (RAMPs) modulate the activity of many Family B GPCRs. We show that RAMP2 directly interacts with the glucagon receptor (GCGR), a Family B GPCR responsible for blood sugar homeostasis, and broadly inhibits receptor-induced downstream signaling. HDX-MS experiments demonstrate that RAMP2 enhances local flexibility in select locations in and near the receptor extracellular domain (ECD) and in the 6(th) transmembrane helix, whereas smFRET experiments show that this ECD disorder results in the inhibition of active and intermediate states of the intracellular surface. We determined the cryo-EM structure of the GCGR-G(s) complex at 2.9 A resolution in the presence of RAMP2. RAMP2 apparently does not interact with GCGR in an ordered manner; however, the receptor ECD is indeed largely disordered along with rearrangements of several intracellular hallmarks of activation. Our studies suggest that RAMP2 acts as a negative allosteric modulator of GCGR by enhancing conformational sampling of the ECD. Negative allosteric modulation of the glucagon receptor by RAMP2.,Krishna Kumar K, O'Brien ES, Habrian CH, Latorraca NR, Wang H, Tuneew I, Montabana E, Marqusee S, Hilger D, Isacoff EY, Mathiesen JM, Kobilka BK Cell. 2023 Mar 30;186(7):1465-1477.e18. doi: 10.1016/j.cell.2023.02.028. PMID:37001505[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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