KEGG   PATHWAY: rro04742
rro04742                    Pathway                                

Taste transduction - Rhinopithecus roxellana (golden snub-nosed monkey)
Five basic tastes are recognized by humans and most other animals - bitter, sweet, sour, salty and umami. In vertebrates, taste stimuli are detected by taste receptor cells (TRCs). At least three distinct cell types are found in mammalian taste buds : type I cells, type II cells, and type III cells. Type I cells express epithelial sodium channel (ENaC) and are considered to be the major mediator of perception of low salt. In type II cells, transduction of bitter, sweet and umami is mediated by a canonical PLC-beta/IP3-signaling cascade, which culminates in the opening of the TRPM5 ion channel. This produces a depolarization that may allow CALMH1 channels to open and release ATP, which serves as a neurotransmitter to activate closely associated nerve afferents expressing P2X2, P2X3 receptors and adjacent type III cells expressing P2Y4 receptors. Type II taste cells also secrete acetylcholine (ACh) that appears to stimulate muscarinic receptors, specifically M3, on the same or neighboring Type II cells. This muscarinic feedback augments taste-evoked release of ATP. In type III cells, sour taste is initiated when protons enter through apically located proton-selective ion channels: polycystic kidney disease 2-like 1 protein (PKD2L1) and polycystic kidney disease 1-like 3 protein (PKD1L3) channels. Weak acids may also activate sour cells by penetrating the cell membrane and leading to closure of resting K+ channels and membrane depolarization. Further, voltage-gated Ca2+ channels are activated and release vesicular serotonin (5-HT), norepinephrine (NE) and gamma-aminobutyric acid (GABA). 5-HT and GABA provide negative paracrine feedback onto receptor cells by activating 5-HT1A and GABAA, GABAB receptors, respectively. 5-HT also functions as a transmitter between presynaptic cells and the sensory afferent.
Organismal Systems; Sensory system
Pathway map
rro04742  Taste transduction

Other DBs
GO: 0050909
Rhinopithecus roxellana (golden snub-nosed monkey) [GN:rro]
104680125  SCNN1A; amiloride-sensitive sodium channel subunit alpha isoform X2 [KO:K04824]
104658244  SCNN1B; amiloride-sensitive sodium channel subunit beta isoform X2 [KO:K04825]
104658243  SCNN1G; amiloride-sensitive sodium channel subunit gamma isoform X1 [KO:K04827]
104669638  ENTPD2; ectonucleoside triphosphate diphosphohydrolase 2 isoform X2 [KO:K01509] [EC:3.6.1.-]
104679840  TAS1R2; taste receptor type 1 member 2 [KO:K04625]
104673322  TAS1R3; taste receptor type 1 member 3 isoform X1 [KO:K04626]
104680203  GNAT3; guanine nucleotide-binding protein G(t) subunit alpha-3 [KO:K19729]
104680094  GNB3; guanine nucleotide-binding protein G(I)/G(S)/G(T) subunit beta-3 [KO:K07825]
115895307  GNG13; guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit gamma-13 [KO:K04547]
104662674  ADCY4; adenylate cyclase type 4 isoform X1 [KO:K08044] [EC:]
104654871  ADCY6; adenylate cyclase type 6 [KO:K08046] [EC:]
104675683  ADCY8; adenylate cyclase type 8 isoform X1 [KO:K08048] [EC:]
104662061  PRKACG; cAMP-dependent protein kinase catalytic subunit gamma isoform X1 [KO:K04345] [EC:]
104677489  PRKACB; cAMP-dependent protein kinase catalytic subunit beta isoform X1 [KO:K04345] [EC:]
104661051  LOW QUALITY PROTEIN: cAMP-dependent protein kinase catalytic subunit alpha [KO:K04345] [EC:]
104655777  PLCB4; 1-phosphatidylinositol 4,5-bisphosphate phosphodiesterase beta-4 isoform X1 [KO:K05858] [EC:]
104673127  PLCB3; 1-phosphatidylinositol 4,5-bisphosphate phosphodiesterase beta-3 [KO:K05858] [EC:]
104668296  PLCB1; 1-phosphatidylinositol 4,5-bisphosphate phosphodiesterase beta-1 isoform X1 [KO:K05858] [EC:]
104659669  PLCB2; 1-phosphatidylinositol 4,5-bisphosphate phosphodiesterase beta-2 isoform X1 [KO:K05858] [EC:]
104658948  ITPR3; inositol 1,4,5-trisphosphate receptor type 3 [KO:K04960]
104677107  TRPM5; transient receptor potential cation channel subfamily M member 5 isoform X1 [KO:K04980]
104663916  SCN2A; sodium channel protein type 2 subunit alpha isoform X1 [KO:K04834]
104663918  sodium channel protein type 3 subunit alpha [KO:K04836]
104663908  SCN9A; sodium channel protein type 9 subunit alpha isoform X1 [KO:K04841]
104656543  CALHM1; calcium homeostasis modulator protein 1 [KO:K19738]
104674327  P2RX2; P2X purinoceptor 2 isoform X1 [KO:K05216]
104654292  P2RX3; P2X purinoceptor 3 [KO:K05217]
104669185  P2RY1; P2Y purinoceptor 1 [KO:K04270]
104678783  P2RY4; P2Y purinoceptor 4 [KO:K04271]
104679194  CHRM3; muscarinic acetylcholine receptor M3 [KO:K04131]
104657571  TAS1R1; taste receptor type 1 member 1 isoform X1 [KO:K04624]
104658139  GRM4; metabotropic glutamate receptor 4 [KO:K04607]
104656977  TAS2R1; taste receptor type 2 member 1 [KO:K08474]
104659710  TAS2R3; taste receptor type 2 member 3 [KO:K08474]
104659711  TAS2R4; taste receptor type 2 member 4 [KO:K08474]
104659712  TAS2R5; taste receptor type 2 member 5 [KO:K08474]
104659718  TAS2R38; taste receptor type 2 member 38 [KO:K08474]
104672858  taste receptor type 2 member 50 [KO:K08474]
104672859  taste receptor type 2 member 20 [KO:K08474]
104666001  TAS2R16; taste receptor type 2 member 16 [KO:K08474]
104674915  TAS2R39; LOW QUALITY PROTEIN: taste receptor type 2 member 39 [KO:K08474]
104674916  TAS2R40; taste receptor type 2 member 40 [KO:K08474]
104674924  TAS2R60; LOW QUALITY PROTEIN: taste receptor type 2 member 60 [KO:K08474]
104674925  TAS2R41; taste receptor type 2 member 41 [KO:K08474]
104674186  taste receptor type 2 member 43 [KO:K08474]
104674187  LOW QUALITY PROTEIN: taste receptor type 2 member 19-like [KO:K08474]
104674188  taste receptor type 2 member 31-like [KO:K08474]
104674190  taste receptor type 2 member 45-like [KO:K08474]
104674191  taste receptor type 2 member 43 [KO:K08474]
104674192  taste receptor type 2 member 31 [KO:K08474]
104674193  taste receptor type 2 member 46 [KO:K08474]
104674196  TAS2R42; taste receptor type 2 member 42 [KO:K08474]
104674199  LOW QUALITY PROTEIN: taste receptor type 2 member 46-like [KO:K08474]
104668633  TAS2R7; taste receptor type 2 member 7 [KO:K08474]
104668634  TAS2R8; taste receptor type 2 member 8 [KO:K08474]
104668635  TAS2R10; taste receptor type 2 member 10 [KO:K08474]
104659339  TAS2R14; taste receptor type 2 member 14 [KO:K08474]
104682229  TAS2R13; taste receptor type 2 member 13 [KO:K08474]
115900059  LOW QUALITY PROTEIN: taste receptor type 2 member 19-like [KO:K08474]
104654225  PDE1C; calcium/calmodulin-dependent 3',5'-cyclic nucleotide phosphodiesterase 1C isoform X1 [KO:K13755] [EC:]
104666593  PDE1A; calcium/calmodulin-dependent 3',5'-cyclic nucleotide phosphodiesterase 1A isoform X3 [KO:K13755] [EC:]
104670555  PDE1B; calcium/calmodulin-dependent 3',5'-cyclic nucleotide phosphodiesterase 1B isoform X1 [KO:K13755] [EC:]
104656474  PKD2L1; polycystic kidney disease 2-like 1 protein isoform X1 [KO:K04990]
104654785  PKD1L3; LOW QUALITY PROTEIN: polycystic kidney disease protein 1-like 3 [KO:K04989]
104682907  KCNK5; potassium channel subfamily K member 5 [KO:K04916]
104678069  HCN4; potassium/sodium hyperpolarization-activated cyclic nucleotide-gated channel 4 [KO:K04957]
104661142  CACNA1A; voltage-dependent P/Q-type calcium channel subunit alpha-1A isoform X1 [KO:K04344]
104659017  CACNA1C; voltage-dependent L-type calcium channel subunit alpha-1C isoform X1 [KO:K04850]
104682337  GABRA6; gamma-aminobutyric acid receptor subunit alpha-6 isoform X2 [KO:K05175]
104682346  GABRA1; gamma-aminobutyric acid receptor subunit alpha-1 [KO:K05175]
104680072  GABRA4; gamma-aminobutyric acid receptor subunit alpha-4 isoform X1 [KO:K05175]
104655705  GABRA5; gamma-aminobutyric acid receptor subunit alpha-5 [KO:K05175]
104658086  GABRA2; gamma-aminobutyric acid receptor subunit alpha-2 isoform X2 [KO:K05175]
104657770  GABBR2; gamma-aminobutyric acid type B receptor subunit 2 [KO:K04615]
104676766  GABBR1; gamma-aminobutyric acid type B receptor subunit 1 isoform X1 [KO:K04615]
104666170  HTR1A; 5-hydroxytryptamine receptor 1A [KO:K04153]
104663235  HTR1D; 5-hydroxytryptamine receptor 1D [KO:K04153]
104670760  HTR1F; 5-hydroxytryptamine receptor 1F [KO:K04153]
104664927  HTR1B; 5-hydroxytryptamine receptor 1B [KO:K04153]
104681604  HTR1E; 5-hydroxytryptamine receptor 1E [KO:K04153]
104664637  HTR3E; LOW QUALITY PROTEIN: 5-hydroxytryptamine receptor 3E [KO:K04819]
104664661  HTR3C; LOW QUALITY PROTEIN: 5-hydroxytryptamine receptor 3C [KO:K04819]
115895917  LOW QUALITY PROTEIN: 5-hydroxytryptamine receptor 3B-like [KO:K04819]
104669405  HTR3A; 5-hydroxytryptamine receptor 3A isoform X1 [KO:K04819]
104669407  HTR3B; 5-hydroxytryptamine receptor 3B isoform X1 [KO:K04819]
104664659  LOW QUALITY PROTEIN: 5-hydroxytryptamine receptor 3C-like [KO:K04819]
104664638  HTR3D; 5-hydroxytryptamine receptor 3D isoform X1 [KO:K04819]
104669321  ASIC2; LOW QUALITY PROTEIN: acid-sensing ion channel 2 [KO:K04828]
C00002  ATP
C00008  ADP
C00020  AMP
C00025  L-Glutamate
C00031  D-Glucose
C00076  Calcium cation
C00080  H+
C00089  Sucrose
C00095  D-Fructose
C00130  IMP
C00133  D-Alanine
C00144  GMP
C00149  (S)-Malate
C00158  Citrate
C00208  Maltose
C00238  Potassium cation
C00334  4-Aminobutanoate
C00547  L-Noradrenaline
C00575  3',5'-Cyclic AMP
C00740  D-Serine
C00780  Serotonin
C01245  D-myo-Inositol 1,4,5-trisphosphate
C01327  Hydrochloric acid
C01330  Sodium cation
C01451  Salicin
C01996  Acetylcholine
C02265  D-Phenylalanine
C06526  Quinine
C11045  Aspartame
C12283  Saccharin
C12284  Saccharin sodium anhydrous
C19378  Cyclamate
D08836  Acesulfame potassium (NF)
Liman ER, Zhang YV, Montell C
Peripheral coding of taste.
Neuron 81:984-1000 (2014)
Kinnamon SC, Finger TE
A taste for ATP: neurotransmission in taste buds.
Front Cell Neurosci 7:264 (2013)
Roper SD
Taste buds as peripheral chemosensory processors.
Semin Cell Dev Biol 24:71-9 (2013)
Kinnamon SC
Taste receptor signalling - from tongues to lungs.
Acta Physiol (Oxf) 204:158-68 (2012)
Kinnamon SC
Neurosensory transmission without a synapse: new perspectives on taste signaling.
BMC Biol 11:42 (2013)
Chaudhari N, Roper SD
The cell biology of taste.
J Cell Biol 190:285-96 (2010)
Vandenbeuch A, Kinnamon SC
Why do taste cells generate action potentials?
J Biol 8:42 (2009)
Chandrashekar J, Hoon MA, Ryba NJ, Zuker CS
The receptors and cells for mammalian taste.
Nature 444:288-94 (2006)
Vandenbeuch A, Anderson CB, Parnes J, Enjyoji K, Robson SC, Finger TE, Kinnamon SC
Role of the ectonucleotidase NTPDase2 in taste bud function.
Proc Natl Acad Sci U S A 110:14789-94 (2013)
Taruno A, Vingtdeux V, Ohmoto M, Ma Z, Dvoryanchikov G, Li A, Adrien L, Zhao H, Leung S, Abernethy M, Koppel J, Davies P, Civan MM, Chaudhari N, Matsumoto I, Hellekant G, Tordoff MG, Marambaud P, Foskett JK
CALHM1 ion channel mediates purinergic neurotransmission of sweet, bitter and umami tastes.
Nature 495:223-6 (2013)
Gao N, Lu M, Echeverri F, Laita B, Kalabat D, Williams ME, Hevezi P, Zlotnik A, Moyer BD
Voltage-gated sodium channels in taste bud cells.
BMC Neurosci 10:20 (2009)
Zheng W, Hussein S, Yang J, Huang J, Zhang F, Hernandez-Anzaldo S, Fernandez-Patron C, Cao Y, Zeng H, Tang J, Chen XZ
A novel PKD2L1 C-terminal domain critical for trimerization and channel function.
Sci Rep 5:9460 (2015)
Shimada S, Ueda T, Ishida Y, Yamamoto T, Ugawa S
Acid-sensing ion channels in taste buds.
Arch Histol Cytol 69:227-31 (2006)
Dando R, Roper SD
Acetylcholine is released from taste cells, enhancing taste signalling.
J Physiol 590:3009-17 (2012)
Kaya N, Shen T, Lu SG, Zhao FL, Herness S
A paracrine signaling role for serotonin in rat taste buds: expression and localization of serotonin receptor subtypes.
Am J Physiol Regul Integr Comp Physiol 286:R649-58 (2004)
rro04020  Calcium signaling pathway
KO pathway

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