TAS2R1

Bitter taste receptors are expressed in taste receptor cells, which organized into taste buds on the papillae of the tongue and palate epithelium.

In addition, TAS2Rs were found to be expressed in extra-oral tissues, e.g. brain, lungs, gastrointestinal tract, etc. So far, less is known about their function however, for example it was shown that:

• TAS2Rs mediate relaxation of airway smooth muscles.{{cite journal | vauthors = Deshpande DA, Wang WC, McIlmoyle EL, Robinett KS, Schillinger RM, An SS, Sham JS, Liggett SB | title = Bitter taste receptors on airway smooth muscle bronchodilate by localized calcium signaling and reverse obstruction | journal = Nature Medicine | volume = 16 | issue = 11 | pages = 1299–1304 | date = November 2010 | pmid = 20972434 | pmc = 3066567 | doi = 10.1038/nm.2237 }}
• TAS2R43 is involved in secretion of gastric acid in the stomach.{{cite journal | vauthors = Liszt KI, Ley JP, Lieder B, Behrens M, Stöger V, Reiner A, Hochkogler CM, Köck E, Marchiori A, Hans J, Widder S, Krammer G, Sanger GJ, Somoza MM, Meyerhof W, Somoza V | title = Caffeine induces gastric acid secretion via bitter taste signaling in gastric parietal cells | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 114 | issue = 30 | pages = E6260–E6269 | date = July 2017 | pmid = 28696284 | pmc = 5544304 | doi = 10.1073/pnas.1703728114 | doi-access = free | bibcode = 2017PNAS..114E6260L }}

• TAS2R1, TAS2R4, TAS2R10, TAS2R38 and TAS2R49 were found to be down-regulated in breast cancer cells{{cite journal | vauthors = Singh N, Chakraborty R, Bhullar RP, Chelikani P | title = Differential expression of bitter taste receptors in non-cancerous breast epithelial and breast cancer cells | journal = Biochemical and Biophysical Research Communications | volume = 446 | issue = 2 | pages = 499–503 | date = April 2014 | pmid = 24613843 | doi = 10.1016/j.bbrc.2014.02.140 }}.
• TAS2R1, causes vasoconstrictor responses in the pulmonary circuit and relaxation in the airways{{cite journal | vauthors = Upadhyaya JD, Singh N, Sikarwar AS, Chakraborty R, Pydi SP, Bhullar RP, Dakshinamurti S, Chelikani P | title = Dextromethorphan mediated bitter taste receptor activation in the pulmonary circuit causes vasoconstriction | journal = PLOS ONE | volume = 9 | issue = 10 | pages = e110373 | date = 2014-10-23 | pmid = 25340739 | pmc = 4207743 | doi = 10.1371/journal.pone.0110373 | doi-access = free | bibcode = 2014PLoSO...9k0373U }}.

Based on a recent homology model from [http://bitterdb.agri.huji.ac.il/Receptor.php?mode_organism=default&id=1 BitterDB]{{cite journal | vauthors = Wiener A, Shudler M, Levit A, Niv MY | title = BitterDB: a database of bitter compounds | journal = Nucleic Acids Research | volume = 40 | issue = Database issue | pages = D413–D419 | date = January 2012 | pmid = 21940398 | pmc = 3245057 | doi = 10.1093/nar/gkr755 }}{{cite journal | vauthors = Dagan-Wiener A, Di Pizio A, Nissim I, Bahia MS, Dubovski N, Margulis E, Niv MY | title = BitterDB: taste ligands and receptors database in 2019 | journal = Nucleic Acids Research | volume = 47 | issue = D1 | pages = D1179–D1185 | date = January 2019 | pmid = 30357384 | pmc = 6323989 | doi = 10.1093/nar/gky974 }} several conserved motifs, which are counterparts to Class A GPCRs were found:

• Transmembrane helix 1: N^1.50xxI^1.53
• Transmembrane helix 2: L^2.46xxxR^2.50
• Transmembrane helix 3: F^3.49Y^3.50xxK^3.53
• Transmembrane helix 5: P^5.50
• Transmembrane helix 6: F^6.44xxxY^6.46
• Transmembrane helix 7: H^7.49S^7.50xxL^7.53

Numbering is according to the Balleros-Weinstein system{{cite book | vauthors = Ballesteros JA, Weinstein H | title=Receptor Molecular Biology | chapter=Integrated methods for the construction of three-dimensional models and computational probing of structure-function relations in G protein-coupled receptors |date=1995| series = Methods in Neurosciences | volume = 25 |pages=366–428|publisher=Elsevier|isbn=978-0-12-185295-5|doi=10.1016/s1043-9471(05)80049-7}}

Unlike in Class A GPCRs, in transmembrane helix 4 no DRY{{cite journal | vauthors = Rovati GE, Capra V, Neubig RR | title = The highly conserved DRY motif of class A G protein-coupled receptors: beyond the ground state | journal = Molecular Pharmacology | volume = 71 | issue = 4 | pages = 959–964 | date = April 2007 | pmid = 17192495 | doi = 10.1124/mol.106.029470 | s2cid = 15536186 }} motif was found as well as position 6.50 is not conserved.

This gene encodes a member of a family of candidate taste receptors that are members of the G protein-coupled receptor superfamily and that are specifically expressed by taste receptor cells of the tongue and palate epithelia. This intronless taste receptor gene encodes a 7-transmembrane receptor protein, functioning as a bitter taste receptor.

In T2R1 two SNPs are known in R111H and R206W (dbSNP).

So far, AML1a, AP-1, AREB6, FOXL1, IRF-7A, Lmo2, NF-E2, NF-E2 p45 were found as the top transcription factor binding sites by QIAGEN in the [https://www.genecards.org/cgi-bin/carddisp.pl?gene=TAS2R1 TAS2R1 gene promoter].

Several mutations have been shown to influence binding of a ligand to TAS2R1 (based on [http://bitterdb.agri.huji.ac.il/Receptor.php?mode_organism=default&id=1 BitterDB]):

Up to now, 39 ligands for T2R1 were identified in BitterDB, among them L-amino acids, peptides, humulones, small molecules etc.{{BitterDB receptor|id=1|title=hTAS2R1}}

• Taste receptor

{{reflist}}

{{refbegin | 2}}

• {{cite journal | vauthors = Kinnamon SC | title = A plethora of taste receptors | journal = Neuron | volume = 25 | issue = 3 | pages = 507–510 | date = March 2000 | pmid = 10774719 | doi = 10.1016/S0896-6273(00)81054-5 | doi-access = free }}
• {{cite journal | vauthors = Margolskee RF | title = Molecular mechanisms of bitter and sweet taste transduction | journal = The Journal of Biological Chemistry | volume = 277 | issue = 1 | pages = 1–4 | date = January 2002 | pmid = 11696554 | doi = 10.1074/jbc.R100054200 | doi-access = free }}
• {{cite journal | vauthors = Montmayeur JP, Matsunami H | title = Receptors for bitter and sweet taste | journal = Current Opinion in Neurobiology | volume = 12 | issue = 4 | pages = 366–371 | date = August 2002 | pmid = 12139982 | doi = 10.1016/S0959-4388(02)00345-8 | s2cid = 37807140 }}
• {{cite journal | vauthors = Chandrashekar J, Mueller KL, Hoon MA, Adler E, Feng L, Guo W, Zuker CS, Ryba NJ | title = T2Rs function as bitter taste receptors | journal = Cell | volume = 100 | issue = 6 | pages = 703–711 | date = March 2000 | pmid = 10761935 | doi = 10.1016/S0092-8674(00)80706-0 | s2cid = 7293493 | doi-access = free }}
• {{cite journal | vauthors = Firestein S | title = The good taste of genomics | journal = Nature | volume = 404 | issue = 6778 | pages = 552–553 | date = April 2000 | pmid = 10766221 | doi = 10.1038/35007167 | s2cid = 35741332 | doi-access = free }}
• {{cite journal | vauthors = Zhang Y, Hoon MA, Chandrashekar J, Mueller KL, Cook B, Wu D, Zuker CS, Ryba NJ | title = Coding of sweet, bitter, and umami tastes: different receptor cells sharing similar signaling pathways | journal = Cell | volume = 112 | issue = 3 | pages = 293–301 | date = February 2003 | pmid = 12581520 | doi = 10.1016/S0092-8674(03)00071-0 | s2cid = 718601 | doi-access = free }}
• {{cite journal | vauthors = Fischer A, Gilad Y, Man O, Pääbo S | title = Evolution of bitter taste receptors in humans and apes | journal = Molecular Biology and Evolution | volume = 22 | issue = 3 | pages = 432–436 | date = March 2005 | pmid = 15496549 | doi = 10.1093/molbev/msi027 | doi-access = free }}
• {{cite journal | vauthors = Go Y, Satta Y, Takenaka O, Takahata N | title = Lineage-specific loss of function of bitter taste receptor genes in humans and nonhuman primates | journal = Genetics | volume = 170 | issue = 1 | pages = 313–326 | date = May 2005 | pmid = 15744053 | pmc = 1449719 | doi = 10.1534/genetics.104.037523 }}

{{refend}}

{{G protein-coupled receptors|g3}}

{{NLM content}}

Category:Human taste receptors