KEGG   PATHWAY: hsa04742Help
Entry
hsa04742                    Pathway                                

Name
Taste transduction - Homo sapiens (human)
Description
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.
Class
Organismal Systems; Sensory system
BRITE hierarchy
Pathway map
Taste transduction
hsa04742

All organismsOrtholog table
Drug
D00025  
Sucrose (JP17/NF)
D00386  
Triamterene (JP17/USP/INN)
D01085  
Saccharin (JP17/NF)
D02192  
Saccharin sodium (USP)
D02381  
Aspartame (NF/INN)
D05781  
Saccharin calcium (USP)
D08500  
Saccharin sodium
D08836  
Acesulfame potassium (NF)
D08862  
Aspartame acesulfame (NF)
Other DBs
BSID: 
GO: 
Organism
Homo sapiens (human) [GN:hsa]
Gene
6337  
SCNN1A; sodium channel epithelial 1 alpha subunit [KO:K04824]
6338  
SCNN1B; sodium channel epithelial 1 beta subunit [KO:K04825]
6340  
SCNN1G; sodium channel epithelial 1 gamma subunit [KO:K04827]
954  
ENTPD2; ectonucleoside triphosphate diphosphohydrolase 2 [KO:K01509] [EC:3.6.1.3]
80834  
TAS1R2; taste 1 receptor member 2 [KO:K04625]
83756  
TAS1R3; taste 1 receptor member 3 [KO:K04626]
346562  
GNAT3; G protein subunit alpha transducin 3 [KO:K19729]
2784  
GNB3; G protein subunit beta 3 [KO:K07825]
51764  
GNG13; G protein subunit gamma 13 [KO:K04547]
196883  
ADCY4; adenylate cyclase 4 [KO:K08044] [EC:4.6.1.1]
112  
ADCY6; adenylate cyclase 6 [KO:K08046] [EC:4.6.1.1]
114  
ADCY8; adenylate cyclase 8 (brain) [KO:K08048] [EC:4.6.1.1]
5566  
PRKACA; protein kinase cAMP-activated catalytic subunit alpha [KO:K04345] [EC:2.7.11.11]
5567  
PRKACB; protein kinase cAMP-activated catalytic subunit beta [KO:K04345] [EC:2.7.11.11]
5568  
PRKACG; protein kinase cAMP-activated catalytic subunit gamma [KO:K04345] [EC:2.7.11.11]
3710  
ITPR3; inositol 1,4,5-trisphosphate receptor type 3 [KO:K04960]
29850  
TRPM5; transient receptor potential cation channel subfamily M member 5 [KO:K04980]
6326  
SCN2A; sodium voltage-gated channel alpha subunit 2 [KO:K04834]
6328  
SCN3A; sodium voltage-gated channel alpha subunit 3 [KO:K04836]
6335  
SCN9A; sodium voltage-gated channel alpha subunit 9 [KO:K04841]
255022  
CALHM1; calcium homeostasis modulator 1 [KO:K19738]
22953  
P2RX2; purinergic receptor P2X 2 [KO:K05216]
5024  
P2RX3; purinergic receptor P2X 3 [KO:K05217]
5028  
P2RY1; purinergic receptor P2Y1 [KO:K04270]
5030  
P2RY4; pyrimidinergic receptor P2Y4 [KO:K04271]
1131  
CHRM3; cholinergic receptor muscarinic 3 [KO:K04131]
80835  
TAS1R1; taste 1 receptor member 1 [KO:K04624]
2911  
GRM1; glutamate metabotropic receptor 1 [KO:K04603]
2914  
GRM4; glutamate metabotropic receptor 4 [KO:K04607]
259285  
TAS2R39; taste 2 receptor member 39 [KO:K08474]
259286  
TAS2R40; taste 2 receptor member 40 [KO:K08474]
259287  
TAS2R41; taste 2 receptor member 41 [KO:K08474]
259289  
TAS2R43; taste 2 receptor member 43 [KO:K08474]
259290  
TAS2R31; taste 2 receptor member 31 [KO:K08474]
259291  
TAS2R45; taste 2 receptor member 45 [KO:K08474]
259292  
TAS2R46; taste 2 receptor member 46 [KO:K08474]
259294  
TAS2R19; taste 2 receptor member 19 [KO:K08474]
259295  
TAS2R20; taste 2 receptor member 20 [KO:K08474]
259296  
TAS2R50; taste 2 receptor member 50 [KO:K08474]
338398  
TAS2R60; taste 2 receptor member 60 [KO:K08474]
353164  
TAS2R42; taste 2 receptor member 42 [KO:K08474]
50831  
TAS2R3; taste 2 receptor member 3 [KO:K08474]
50832  
TAS2R4; taste 2 receptor member 4 [KO:K08474]
50833  
TAS2R16; taste 2 receptor member 16 [KO:K08474]
50834  
TAS2R1; taste 2 receptor member 1 [KO:K08474]
50835  
TAS2R9; taste 2 receptor member 9 [KO:K08474]
50836  
TAS2R8; taste 2 receptor member 8 [KO:K08474]
50837  
TAS2R7; taste 2 receptor member 7 [KO:K08474]
50838  
TAS2R13; taste 2 receptor member 13 [KO:K08474]
50839  
TAS2R10; taste 2 receptor member 10 [KO:K08474]
50840  
TAS2R14; taste 2 receptor member 14 [KO:K08474]
54429  
TAS2R5; taste 2 receptor member 5 [KO:K08474]
5726  
TAS2R38; taste 2 receptor member 38 [KO:K08474]
259293  
TAS2R30; taste 2 receptor member 30 [KO:K08474]
5136  
PDE1A; phosphodiesterase 1A [KO:K13755] [EC:3.1.4.17]
5153  
PDE1B; phosphodiesterase 1B [KO:K13755] [EC:3.1.4.17]
5137  
PDE1C; phosphodiesterase 1C [KO:K13755] [EC:3.1.4.17]
9033  
PKD2L1; polycystin 2 like 1, transient receptor potential cation channel [KO:K04990]
342372  
PKD1L3; polycystin 1 like 3, transient receptor potential channel interacting [KO:K04989]
8645  
KCNK5; potassium two pore domain channel subfamily K member 5 [KO:K04916]
10021  
HCN4; hyperpolarization activated cyclic nucleotide gated potassium channel 4 [KO:K04957]
773  
CACNA1A; calcium voltage-gated channel subunit alpha1 A [KO:K04344]
775  
CACNA1C; calcium voltage-gated channel subunit alpha1 C [KO:K04850]
2554  
GABRA1; gamma-aminobutyric acid type A receptor alpha1 subunit [KO:K05175]
2555  
GABRA2; gamma-aminobutyric acid type A receptor alpha2 subunit [KO:K05175]
2556  
GABRA3; gamma-aminobutyric acid type A receptor alpha3 subunit [KO:K05175]
2557  
GABRA4; gamma-aminobutyric acid type A receptor alpha4 subunit [KO:K05175]
2558  
GABRA5; gamma-aminobutyric acid type A receptor alpha5 subunit [KO:K05175]
2559  
GABRA6; gamma-aminobutyric acid type A receptor alpha6 subunit [KO:K05175]
2550  
GABBR1; gamma-aminobutyric acid type B receptor subunit 1 [KO:K04615]
9568  
GABBR2; gamma-aminobutyric acid type B receptor subunit 2 [KO:K04615]
3350  
HTR1A; 5-hydroxytryptamine receptor 1A [KO:K04153]
3351  
HTR1B; 5-hydroxytryptamine receptor 1B [KO:K04153]
3352  
HTR1D; 5-hydroxytryptamine receptor 1D [KO:K04153]
3354  
HTR1E; 5-hydroxytryptamine receptor 1E [KO:K04153]
3355  
HTR1F; 5-hydroxytryptamine receptor 1F [KO:K04153]
3359  
HTR3A; 5-hydroxytryptamine receptor 3A [KO:K04819]
285242  
HTR3E; 5-hydroxytryptamine receptor 3E [KO:K04819]
200909  
HTR3D; 5-hydroxytryptamine receptor 3D [KO:K04819]
170572  
HTR3C; 5-hydroxytryptamine receptor 3C [KO:K04819]
9177  
HTR3B; 5-hydroxytryptamine receptor 3B [KO:K04819]
40  
ASIC2; acid sensing ion channel subunit 2 [KO:K04828]
5330  
PLCB2; phospholipase C beta 2 [KO:K05858] [EC:3.1.4.11]
Compound
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)
Reference
  Authors
Liman ER, Zhang YV, Montell C
  Title
Peripheral coding of taste.
  Journal
Neuron 81:984-1000 (2014)
Reference
  Authors
Kinnamon SC, Finger TE
  Title
A taste for ATP: neurotransmission in taste buds.
  Journal
Front Cell Neurosci 7:264 (2013)
Reference
  Authors
Roper SD
  Title
Taste buds as peripheral chemosensory processors.
  Journal
Semin Cell Dev Biol 24:71-9 (2013)
Reference
  Authors
Kinnamon SC
  Title
Taste receptor signalling - from tongues to lungs.
  Journal
Acta Physiol (Oxf) 204:158-68 (2012)
Reference
  Authors
Kinnamon SC
  Title
Neurosensory transmission without a synapse: new perspectives on taste signaling.
  Journal
BMC Biol 11:42 (2013)
Reference
  Authors
Chaudhari N, Roper SD
  Title
The cell biology of taste.
  Journal
J Cell Biol 190:285-96 (2010)
Reference
  Authors
Vandenbeuch A, Kinnamon SC
  Title
Why do taste cells generate action potentials?
  Journal
J Biol 8:42 (2009)
Reference
  Authors
Chandrashekar J, Hoon MA, Ryba NJ, Zuker CS
  Title
The receptors and cells for mammalian taste.
  Journal
Nature 444:288-94 (2006)
Reference
  Authors
Vandenbeuch A, Anderson CB, Parnes J, Enjyoji K, Robson SC, Finger TE, Kinnamon SC
  Title
Role of the ectonucleotidase NTPDase2 in taste bud function.
  Journal
Proc Natl Acad Sci U S A 110:14789-94 (2013)
Reference
  Authors
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
  Title
CALHM1 ion channel mediates purinergic neurotransmission of sweet, bitter and umami tastes.
  Journal
Nature 495:223-6 (2013)
Reference
  Authors
Gao N, Lu M, Echeverri F, Laita B, Kalabat D, Williams ME, Hevezi P, Zlotnik A, Moyer BD
  Title
Voltage-gated sodium channels in taste bud cells.
  Journal
BMC Neurosci 10:20 (2009)
Reference
  Authors
Zheng W, Hussein S, Yang J, Huang J, Zhang F, Hernandez-Anzaldo S, Fernandez-Patron C, Cao Y, Zeng H, Tang J, Chen XZ
  Title
A novel PKD2L1 C-terminal domain critical for trimerization and channel function.
  Journal
Sci Rep 5:9460 (2015)
Reference
  Authors
Shimada S, Ueda T, Ishida Y, Yamamoto T, Ugawa S
  Title
Acid-sensing ion channels in taste buds.
  Journal
Arch Histol Cytol 69:227-31 (2006)
Reference
  Authors
Dando R, Roper SD
  Title
Acetylcholine is released from taste cells, enhancing taste signalling.
  Journal
J Physiol 590:3009-17 (2012)
Reference
  Authors
Kaya N, Shen T, Lu SG, Zhao FL, Herness S
  Title
A paracrine signaling role for serotonin in rat taste buds: expression and localization of serotonin receptor subtypes.
  Journal
Am J Physiol Regul Integr Comp Physiol 286:R649-58 (2004)
KO pathway
 

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