7xp5
From Proteopedia
Cryo-EM structure of a class T GPCR in ligand-free state
Structural highlights
FunctionT2R46_HUMAN Receptor that may play a role in the perception of bitterness and is gustducin-linked. May play a role in sensing the chemical composition of the gastrointestinal content. The activity of this receptor may stimulate alpha gustducin, mediate PLC-beta-2 activation and lead to the gating of TRPM5 (By similarity). In airway epithelial cells, binding of bitter compounds increases the intracellular calcium ion concentration and stimulates ciliary beat frequency (By similarity).GUNH_ACET2 This enzyme catalyzes the endohydrolysis of 1,4-beta-glucosidic linkages in cellulose, lichenin and cereal beta-D-glucans. Publication Abstract from PubMedTaste sensing is a sophisticated chemosensory process, and bitter taste perception is mediated by type 2 taste receptors (TAS2Rs), or class T G protein-coupled receptors. Understanding the detailed molecular mechanisms behind taste sensation is hindered by a lack of experimental receptor structures. Here, we report the cryo-electron microscopy structures of human TAS2R46 complexed with chimeric mini-G protein gustducin, in both strychnine-bound and apo forms. Several features of TAS2R46 are disclosed, including distinct receptor structures that compare with known GPCRs, a new "toggle switch," activation-related motifs, and precoupling with mini-G protein gustducin. Furthermore, the dynamic extracellular and more-static intracellular parts of TAS2R46 suggest possible diverse ligand-recognition and activation processes. This study provides a basis for further exploration of other bitter taste receptors and their therapeutic applications. Structural basis for strychnine activation of human bitter taste receptor TAS2R46.,Xu W, Wu L, Liu S, Liu X, Cao X, Zhou C, Zhang J, Fu Y, Guo Y, Wu Y, Tan Q, Wang L, Liu J, Jiang L, Fan Z, Pei Y, Yu J, Cheng J, Zhao S, Hao X, Liu ZJ, Hua T Science. 2022 Sep 16;377(6612):1298-1304. doi: 10.1126/science.abo1633. Epub 2022 , Sep 15. PMID:36108005[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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