| Structural highlights
Disease
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
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).[1] [2] [3] [4] [5]
Publication Abstract from PubMed
GPR21 is a class-A orphan G protein-coupled receptor (GPCR) and a potential therapeutic target for type 2 diabetes and other metabolic disorders. This receptor shows high basal activity in coupling to multiple G proteins in the absence of any known endogenous agonist or synthetic ligand. Here, we present the structures of ligand-free human GPR21 bound to heterotrimeric miniGs and miniG15 proteins, respectively. We identified an agonist-like motif in extracellular loop 2 (ECL2) that occupies the orthosteric pocket and promotes receptor activation. A side pocket that may be employed as a new ligand binding site was also uncovered. Remarkably, G protein binding is accommodated by a flexible cytoplasmic portion of transmembrane helix 6 (TM6) which adopts little or undetectable outward movement. These findings will enable the design of modulators for GPR21 for understanding its signal transduction and exploring opportunity for deorphanization.
Cryo-EM structures of orphan GPR21 signaling complexes.,Lin X, Chen B, Wu Y, Han Y, Qi A, Wang J, Yang Z, Wei X, Zhao T, Wu L, Xie X, Sun J, Zheng J, Zhao S, Xu F Nat Commun. 2023 Jan 13;14(1):216. doi: 10.1038/s41467-023-35882-w. PMID:36639690[6]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Pak Y, Pham N, Rotin D. Direct binding of the beta1 adrenergic receptor to the cyclic AMP-dependent guanine nucleotide exchange factor CNrasGEF leads to Ras activation. Mol Cell Biol. 2002 Nov;22(22):7942-52. PMID:12391161
- ↑ Gao X, Sadana R, Dessauer CW, Patel TB. Conditional stimulation of type V and VI adenylyl cyclases by G protein betagamma subunits. J Biol Chem. 2007 Jan 5;282(1):294-302. Epub 2006 Nov 16. PMID:17110384 doi:http://dx.doi.org/10.1074/jbc.M607522200
- ↑ Thiele S, de Sanctis L, Werner R, Grotzinger J, Aydin C, Juppner H, Bastepe M, Hiort O. Functional characterization of GNAS mutations found in patients with pseudohypoparathyroidism type Ic defines a new subgroup of pseudohypoparathyroidism affecting selectively Gsalpha-receptor interaction. Hum Mutat. 2011 Jun;32(6):653-60. doi: 10.1002/humu.21489. Epub 2011 Apr 12. PMID:21488135 doi:http://dx.doi.org/10.1002/humu.21489
- ↑ Brand CS, Sadana R, Malik S, Smrcka AV, Dessauer CW. Adenylyl Cyclase 5 Regulation by Gbetagamma Involves Isoform-Specific Use of Multiple Interaction Sites. Mol Pharmacol. 2015 Oct;88(4):758-67. doi: 10.1124/mol.115.099556. Epub 2015 Jul , 23. PMID:26206488 doi:http://dx.doi.org/10.1124/mol.115.099556
- ↑ Farfel Z, Iiri T, Shapira H, Roitman A, Mouallem M, Bourne HR. Pseudohypoparathyroidism, a novel mutation in the betagamma-contact region of Gsalpha impairs receptor stimulation. J Biol Chem. 1996 Aug 16;271(33):19653-5. PMID:8702665
- ↑ Lin X, Chen B, Wu Y, Han Y, Qi A, Wang J, Yang Z, Wei X, Zhao T, Wu L, Xie X, Sun J, Zheng J, Zhao S, Xu F. Cryo-EM structures of orphan GPR21 signaling complexes. Nat Commun. 2023 Jan 13;14(1):216. PMID:36639690 doi:10.1038/s41467-023-35882-w
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