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{{Infobox_gene}}
{{PBB_Controls
'''Taste receptor type 1 member 2''' is a [[protein]] that in humans is encoded by the ''TAS1R2'' [[gene]].<ref name="entrez">{{cite web | title = Entrez Gene: TAS1R2 taste receptor, type 1, member 2| url = https://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=80834| accessdate = }}</ref>
| update_page = yes
| require_manual_inspection = no
| update_protein_box = yes
| update_summary = yes
| update_citations = yes
}}


<!-- The GNF_Protein_box is automatically maintained by Protein Box Bot.  See Template:PBB_Controls to Stop updates. -->
== Structure ==
{{GNF_Protein_box
| image =
| image_source =
| PDB =  
| Name = Taste receptor, type 1, member 2
| HGNCid = 14905
| Symbol = TAS1R2
| AltSymbols =; TR2; GPR71; T1R2
| OMIM = 606226
| ECnumber = 
| Homologene = 75323
| MGIid = 1933546
| GeneAtlas_image1 = PBB_GE_TAS1R2_gnf1h06475_at_tn.png
| Function = {{GNF_GO|id=GO:0004872 |text = receptor activity}} {{GNF_GO|id=GO:0008067 |text = metabotropic glutamate, GABA-B-like receptor activity}} {{GNF_GO|id=GO:0008527 |text = taste receptor activity}} {{GNF_GO|id=GO:0046982 |text = protein heterodimerization activity}}
| Component = {{GNF_GO|id=GO:0016020 |text = membrane}} {{GNF_GO|id=GO:0016021 |text = integral to membrane}}
| Process = {{GNF_GO|id=GO:0007165 |text = signal transduction}} {{GNF_GO|id=GO:0007186 |text = G-protein coupled receptor protein signaling pathway}} {{GNF_GO|id=GO:0050896 |text = response to stimulus}} {{GNF_GO|id=GO:0050916 |text = sensory perception of sweet taste}}
| Orthologs = {{GNF_Ortholog_box
    | Hs_EntrezGene = 80834
    | Hs_Ensembl = ENSG00000179002
    | Hs_RefseqProtein = NP_689418
    | Hs_RefseqmRNA = NM_152232
    | Hs_GenLoc_db = 
    | Hs_GenLoc_chr = 1
    | Hs_GenLoc_start = 19038680
    | Hs_GenLoc_end = 19058763
    | Hs_Uniprot = Q8TE23
    | Mm_EntrezGene = 83770
    | Mm_Ensembl = 
    | Mm_RefseqmRNA = XM_980714
    | Mm_RefseqProtein = XP_985808
    | Mm_GenLoc_db = 
    | Mm_GenLoc_chr = 
    | Mm_GenLoc_start = 
    | Mm_GenLoc_end = 
    | Mm_Uniprot = 
  }}
}}
'''Taste receptor, type 1, member 2''', also known as '''TAS1R2''', is a human [[gene]].<ref name="entrez">{{cite web | title = Entrez Gene: TAS1R2 taste receptor, type 1, member 2| url = http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=80834| accessdate = }}</ref>


<!-- The PBB_Summary template is automatically maintained by Protein Box Bot.  See Template:PBB_Controls to Stop updates. -->
The protein encoded by the ''TAS1R2'' gene is a [[G protein-coupled receptor]] with seven trans-membrane domains and is a component of the heterodimeric amino acid taste receptor T1R2+3. This receptor is formed as a dimer of the TAS1R2 and [[TAS1R3]] proteins. Moreover, the TAS1R2 protein is not functional without formation of the 2+3 heterodimer.<ref name="Nelson2001">{{cite journal | vauthors = Nelson G, Hoon MA, Chandrashekar J, Zhang Y, Ryba NJ, Zuker CS | title = Mammalian sweet taste receptors | journal = Cell | volume = 106 | issue = 3 | pages = 381–390 | year = 2001 | pmid = 11509186 | doi = 10.1016/S0092-8674(01)00451-2 }}</ref>
{{PBB_Summary
Another interesting quality of the ''TAS1R2'' and ''[[TAS1R1]]'' genes is their spontaneous activity in the absence of the extracellular domains and binding ligands.<ref name="sainz">{{cite journal | vauthors = Sainz E, Cavenagh MM, LopezJimenez ND, Gutierrez JC, Battey JF, Northup JK, Sullivan SL | title = The G-protein coupling properties of the human sweet and amino acid taste receptors | journal = Developmental Neurobiology | volume = 67 | issue = 7 | pages = 948–959 | year = 2007 | pmid = 17506496 | doi = 10.1002/dneu.20403 }}</ref> This may mean that the extracellular domain regulates function of the receptor by preventing spontaneous action as well as binding to activating ligands such as [[sucrose]].
| section_title =  
 
| summary_text =  
== Ligands ==
}}
 
The TAS1R2+3 receptor has been shown to respond to natural sugars [[sucrose]] and [[fructose]], and to the artificial sweeteners [[saccharin]], [[acesulfame potassium]], [[dulcin]], and guanidinoacetic acid.  Research initially suggested that rat receptors did not respond to many other natural and artificial sugars, such as [[glucose]] and [[aspartame]], leading to the conclusion that there must be more than one type of sweet taste receptor.<ref name="Nelson2001" /> Contradictory evidence, however, suggested that cells expressing the human TAS1R2+3 receptor showed sensitivity to both [[aspartame]] and [[glucose]] but cells expressing the rat TAS1R2+3 receptor were only slightly activated by [[glucose]] and showed no [[aspartame]] activation.<ref name="Li">{{cite journal | vauthors = Li X, Staszewski L, Xu H, Durick K, Zoller M, Adler E | title = Human receptors for sweet and umami taste | journal = Proceedings of the National Academy of Sciences | volume = 99 | issue = 7 | pages = 4692–4696 | year = 2002 | pmid = 11917125 | pmc = 123709 | doi = 10.1073/pnas.072090199 }}</ref> These results are inconclusive about the existence of another sweet taste receptor, but show that the TAS1R2+3 receptors are responsible for a wide variety of different sweet tastes.
 
== Signal transduction ==
 
TAS1R2 and [[TAS1R1]] receptors have been shown to bind to [[G protein]]s, most often the [[gustducin]] Gα subunit, although a gusducin knock-out has shown small residual activity. TAS1R2 and [[TAS1R1]] have also been shown to activate Gαo and Gαi protein subunits.<ref name="sainz" /> This suggests that TAS1R1 and TAS1R2 are [[G protein-coupled receptors]] that inhibit [[adenylyl cyclase]]s to decrease [[cyclic guanosine monophosphate]] (cGMP) levels in [[taste receptor]]s.<ref name="Abaffy">{{cite journal | vauthors = Abaffy T, Trubey KR, Chaudhari N | title = Adenylyl cyclase expression and modulation of cAMP in rat taste cells | journal = American Journal of Physiology. Cell Physiology | volume = 284 | issue = 6 | pages = C1420–C1428 | year = 2003 | pmid = 12606315 | doi = 10.1152/ajpcell.00556.2002 }}</ref>  
Research done by creating knock-outs of common channels activated by sensory G-protein [[second messenger systems]] has also shown a connection between sweet taste perception and the [[phosphatidylinositol]] (PIP2) pathway.  The nonselecive cation [[Transient Receptor Potential]] channel TRPM5 has been shown to correlate with both umami and sweet taste.  Also, the [[phospholipase]] PLCβ2 was shown to similarly correlate with umami and sweet taste.  This suggests that activation of the G-protein pathway and subsequent activation of PLC β2 and the TRPM5 channel in these taste cells functions to activate the cell.<ref name="Zhang">{{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 | year = 2003 | pmid = 12581520 | doi = 10.1016/S0092-8674(03)00071-0 }}</ref>
 
== Location and innervation ==
 
TAS1R2+3 expressing cells are found in [[circumvallate papilla]]e and [[foliate papilla]]e near the back of the [[tongue]] and [[palate]] taste receptor cells in the roof of the mouth.<ref name="Nelson2001" />  These cells are shown to [[synapse]] upon the [[chorda tympani]] and [[glossopharyngeal nerve]]s to send their signals to the brain.<ref name="Bachmanov">{{cite journal | vauthors = Beamis JF, Shapshay SM, Setzer S, Dumon JF | title = Teaching models for Nd:YAG laser bronchoscopy | journal = Chest | volume = 95 | issue = 6 | pages = 1316–1318 | year = 1989 | pmid = 2721271 | doi = 10.1378/chest.95.6.1316 }}</ref><ref name="Danilova">{{cite journal | vauthors = Danilova V, Hellekant G | title = Comparison of the responses of the chorda tympani and glossopharyngeal nerves to taste stimuli in C57BL/6J mice | journal = BMC Neuroscience | volume = 4 | pages = 5–6 | year = 2003 | pmid = 12617752 | pmc = 153500 | doi = 10.1186/1471-2202-4-5 }}</ref>
TAS1R and TAS2R (bitter) channels are not expressed together in [[taste bud]]s.<ref name="Nelson2001" />


==See also==
==See also==
* [[Taste receptor]]
* [[Taste receptor]]
* [[TAS1R1]]
* [[TAS1R3]]


==References==
==References==
{{reflist|2}}
{{reflist|35em}}


==Further reading==
==Further reading==
{{refbegin | 2}}
{{refbegin|35em}}
{{PBB_Further_reading
*{{cite journal | vauthors = Chandrashekar J, Hoon MA, Ryba NJ, Zuker CS | title = The receptors and cells for mammalian taste. | journal = Nature | volume = 444 | issue = 7117 | pages = 288–94 | year = 2007 | pmid = 17108952 | doi = 10.1038/nature05401 }}
| citations =
*{{cite journal | vauthors = Hoon MA, Adler E, Lindemeier J, Battey JF, Ryba NJ, Zuker CS | title = Putative mammalian taste receptors: a class of taste-specific GPCRs with distinct topographic selectivity. | journal = Cell | volume = 96 | issue = 4 | pages = 541–51 | year = 1999 | pmid = 10052456 | doi = 10.1016/S0092-8674(00)80658-3 }}
*{{cite journal | author=Chandrashekar J, Hoon MA, Ryba NJ, Zuker CS |title=The receptors and cells for mammalian taste. |journal=Nature |volume=444 |issue= 7117 |pages= 288-94 |year= 2007 |pmid= 17108952 |doi= 10.1038/nature05401 }}
*{{cite journal | vauthors = Li X, Staszewski L, Xu H, Durick K, Zoller M, Adler E | title = Human receptors for sweet and umami taste. | journal = Proc. Natl. Acad. Sci. U.S.A. | volume = 99 | issue = 7 | pages = 4692–6 | year = 2002 | pmid = 11917125 | pmc = 123709 | doi = 10.1073/pnas.072090199 }}
*{{cite journal | author=Hoon MA, Adler E, Lindemeier J, ''et al.'' |title=Putative mammalian taste receptors: a class of taste-specific GPCRs with distinct topographic selectivity. |journal=Cell |volume=96 |issue= 4 |pages= 541-51 |year= 1999 |pmid= 10052456 |doi= }}
*{{cite journal | vauthors = Spadaccini R, Trabucco F, Saviano G, Picone D, Crescenzi O, Tancredi T, Temussi PA | title = The mechanism of interaction of sweet proteins with the T1R2-T1R3 receptor: evidence from the solution structure of G16A-MNEI. | journal = J. Mol. Biol. | volume = 328 | issue = 3 | pages = 683–92 | year = 2003 | pmid = 12706725 | doi = 10.1016/S0022-2836(03)00346-2 }}
*{{cite journal | author=Li X, Staszewski L, Xu H, ''et al.'' |title=Human receptors for sweet and umami taste. |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=99 |issue= 7 |pages= 4692-6 |year= 2002 |pmid= 11917125 |doi= 10.1073/pnas.072090199 }}
*{{cite journal | vauthors = Liao J, Schultz PG | title = Three sweet receptor genes are clustered in human chromosome 1. | journal = Mamm. Genome | volume = 14 | issue = 5 | pages = 291–301 | year = 2003 | pmid = 12856281 | doi = 10.1007/s00335-002-2233-0 }}
*{{cite journal | author=Spadaccini R, Trabucco F, Saviano G, ''et al.'' |title=The mechanism of interaction of sweet proteins with the T1R2-T1R3 receptor: evidence from the solution structure of G16A-MNEI. |journal=J. Mol. Biol. |volume=328 |issue= 3 |pages= 683-92 |year= 2003 |pmid= 12706725 |doi= }}
*{{cite journal | vauthors = Zhao GQ, Zhang Y, Hoon MA, Chandrashekar J, Erlenbach I, Ryba NJ, Zuker CS | title = The receptors for mammalian sweet and umami taste. | journal = Cell | volume = 115 | issue = 3 | pages = 255–66 | year = 2004 | pmid = 14636554 | doi = 10.1016/S0092-8674(03)00844-4 }}
*{{cite journal | author=Liao J, Schultz PG |title=Three sweet receptor genes are clustered in human chromosome 1. |journal=Mamm. Genome |volume=14 |issue= 5 |pages= 291-301 |year= 2003 |pmid= 12856281 |doi= 10.1007/s00335-002-2233-0 }}
*{{cite journal | vauthors = Galindo-Cuspinera V, Winnig M, Bufe B, Meyerhof W, Breslin PA | title = A TAS1R receptor-based explanation of sweet 'water-taste'. | journal = Nature | volume = 441 | issue = 7091 | pages = 354–7 | year = 2006 | pmid = 16633339 | doi = 10.1038/nature04765 }}
*{{cite journal | author=Zhao GQ, Zhang Y, Hoon MA, ''et al.'' |title=The receptors for mammalian sweet and umami taste. |journal=Cell |volume=115 |issue= 3 |pages= 255-66 |year= 2004 |pmid= 14636554 |doi= }}
*{{cite journal | vauthors = Behrens M, Bartelt J, Reichling C, Winnig M, Kuhn C, Meyerhof W | title = Members of RTP and REEP gene families influence functional bitter taste receptor expression. | journal = J. Biol. Chem. | volume = 281 | issue = 29 | pages = 20650–9 | year = 2006 | pmid = 16720576 | doi = 10.1074/jbc.M513637200 }}
*{{cite journal | author=Galindo-Cuspinera V, Winnig M, Bufe B, ''et al.'' |title=A TAS1R receptor-based explanation of sweet 'water-taste'. |journal=Nature |volume=441 |issue= 7091 |pages= 354-7 |year= 2006 |pmid= 16633339 |doi= 10.1038/nature04765 }}
*{{cite journal | author=Gregory SG, Barlow KF, McLay KE, ''et al.'' |title=The DNA sequence and biological annotation of human chromosome 1. |journal=Nature |volume=441 |issue= 7091 |pages= 315-21 |year= 2006 |pmid= 16710414 |doi= 10.1038/nature04727 }}
*{{cite journal  | author=Behrens M, Bartelt J, Reichling C, ''et al.'' |title=Members of RTP and REEP gene families influence functional bitter taste receptor expression. |journal=J. Biol. Chem. |volume=281 |issue= 29 |pages= 20650-9 |year= 2006 |pmid= 16720576 |doi= 10.1074/jbc.M513637200 }}
}}
{{refend}}
{{refend}}


{{membrane-protein-stub}}
==External links==
* [http://www.genecards.org/cgi-bin/carddisp.pl?gene=TAS1R2&search=tas1r2 TAS1R2 Gene]
* [http://omim.org/entry/606226 TASTE RECEPTOR TYPE 1, MEMBER 2; TAS1R2]
 
{{G protein-coupled receptors|g3}}
{{NLM content}}
{{NLM content}}
{{G protein-coupled receptors}}
 
[[Category:G protein coupled receptors]]
[[Category:G protein coupled receptors]]
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Revision as of 00:42, 9 November 2017

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External IDsGeneCards: [1]
Orthologs
SpeciesHumanMouse
Entrez

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Ensembl

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UniProt

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RefSeq (mRNA)

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RefSeq (protein)

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View/Edit Human

Taste receptor type 1 member 2 is a protein that in humans is encoded by the TAS1R2 gene.[1]

Structure

The protein encoded by the TAS1R2 gene is a G protein-coupled receptor with seven trans-membrane domains and is a component of the heterodimeric amino acid taste receptor T1R2+3. This receptor is formed as a dimer of the TAS1R2 and TAS1R3 proteins. Moreover, the TAS1R2 protein is not functional without formation of the 2+3 heterodimer.[2] Another interesting quality of the TAS1R2 and TAS1R1 genes is their spontaneous activity in the absence of the extracellular domains and binding ligands.[3] This may mean that the extracellular domain regulates function of the receptor by preventing spontaneous action as well as binding to activating ligands such as sucrose.

Ligands

The TAS1R2+3 receptor has been shown to respond to natural sugars sucrose and fructose, and to the artificial sweeteners saccharin, acesulfame potassium, dulcin, and guanidinoacetic acid. Research initially suggested that rat receptors did not respond to many other natural and artificial sugars, such as glucose and aspartame, leading to the conclusion that there must be more than one type of sweet taste receptor.[2] Contradictory evidence, however, suggested that cells expressing the human TAS1R2+3 receptor showed sensitivity to both aspartame and glucose but cells expressing the rat TAS1R2+3 receptor were only slightly activated by glucose and showed no aspartame activation.[4] These results are inconclusive about the existence of another sweet taste receptor, but show that the TAS1R2+3 receptors are responsible for a wide variety of different sweet tastes.

Signal transduction

TAS1R2 and TAS1R1 receptors have been shown to bind to G proteins, most often the gustducin Gα subunit, although a gusducin knock-out has shown small residual activity. TAS1R2 and TAS1R1 have also been shown to activate Gαo and Gαi protein subunits.[3] This suggests that TAS1R1 and TAS1R2 are G protein-coupled receptors that inhibit adenylyl cyclases to decrease cyclic guanosine monophosphate (cGMP) levels in taste receptors.[5] Research done by creating knock-outs of common channels activated by sensory G-protein second messenger systems has also shown a connection between sweet taste perception and the phosphatidylinositol (PIP2) pathway. The nonselecive cation Transient Receptor Potential channel TRPM5 has been shown to correlate with both umami and sweet taste. Also, the phospholipase PLCβ2 was shown to similarly correlate with umami and sweet taste. This suggests that activation of the G-protein pathway and subsequent activation of PLC β2 and the TRPM5 channel in these taste cells functions to activate the cell.[6]

Location and innervation

TAS1R2+3 expressing cells are found in circumvallate papillae and foliate papillae near the back of the tongue and palate taste receptor cells in the roof of the mouth.[2] These cells are shown to synapse upon the chorda tympani and glossopharyngeal nerves to send their signals to the brain.[7][8] TAS1R and TAS2R (bitter) channels are not expressed together in taste buds.[2]

See also

References

  1. ↑ "Entrez Gene: TAS1R2 taste receptor, type 1, member 2".
  2. ↑ 2.0 2.1 2.2 2.3 Nelson G, Hoon MA, Chandrashekar J, Zhang Y, Ryba NJ, Zuker CS (2001). "Mammalian sweet taste receptors". Cell. 106 (3): 381–390. doi:10.1016/S0092-8674(01)00451-2. PMID 11509186.
  3. ↑ 3.0 3.1 Sainz E, Cavenagh MM, LopezJimenez ND, Gutierrez JC, Battey JF, Northup JK, Sullivan SL (2007). "The G-protein coupling properties of the human sweet and amino acid taste receptors". Developmental Neurobiology. 67 (7): 948–959. doi:10.1002/dneu.20403. PMID 17506496.
  4. ↑ Li X, Staszewski L, Xu H, Durick K, Zoller M, Adler E (2002). "Human receptors for sweet and umami taste". Proceedings of the National Academy of Sciences. 99 (7): 4692–4696. doi:10.1073/pnas.072090199. PMC 123709. PMID 11917125.
  5. ↑ Abaffy T, Trubey KR, Chaudhari N (2003). "Adenylyl cyclase expression and modulation of cAMP in rat taste cells". American Journal of Physiology. Cell Physiology. 284 (6): C1420–C1428. doi:10.1152/ajpcell.00556.2002. PMID 12606315.
  6. ↑ Zhang Y, Hoon MA, Chandrashekar J, Mueller KL, Cook B, Wu D, Zuker CS, Ryba NJ (2003). "Coding of sweet, bitter, and umami tastes: Different receptor cells sharing similar signaling pathways". Cell. 112 (3): 293–301. doi:10.1016/S0092-8674(03)00071-0. PMID 12581520.
  7. ↑ Beamis JF, Shapshay SM, Setzer S, Dumon JF (1989). "Teaching models for Nd:YAG laser bronchoscopy". Chest. 95 (6): 1316–1318. doi:10.1378/chest.95.6.1316. PMID 2721271.
  8. ↑ Danilova V, Hellekant G (2003). "Comparison of the responses of the chorda tympani and glossopharyngeal nerves to taste stimuli in C57BL/6J mice". BMC Neuroscience. 4: 5–6. doi:10.1186/1471-2202-4-5. PMC 153500. PMID 12617752.

Further reading

External links

This article incorporates text from the United States National Library of Medicine, which is in the public domain.

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