Entry
Name
Olfactory transduction - Homo sapiens (human)
Description
Within the compact cilia of the olfactory receptor neurons (ORNs) a cascade of enzymatic activity transduces the binding of an odorant molecule to a receptor into an electrical signal that can be transmitted to the brain. Odorant molecules bind to a receptor protein (R) coupled to an olfactory specific Gs-protein (G) and activate a type III adenylyl cyclase (AC), increasing intracellular cAMP levels. cAMP targets an olfactory-specific cyclic-nucleotide gated ion channel (CNG), allowing cations, particularly Na and Ca, to flow down their electrochemical gradients into the cell, depolarizing the ORN. Furthermore, the Ca entering the cell is able to activate a Ca-activated Cl channel, which would allow Cl to flow out of the cell, thus further increasing the depolarization. Elevated intracellular Ca causes adaptation by at least two different molecular steps: inhibition of the activity of adenylyl cyclase via CAMKII-dependent phosphorylation and down-regulation of the affinity of the CNG channel to cAMP.
Class
Organismal Systems; Sensory system
BRITE hierarchy
Pathway map
Other DBs
Organism
Homo sapiens (human) [GN:
hsa ]
Gene
105369274 OR4N4C; olfactory receptor family 4 subfamily N member 4C [KO:K04257 ]
123041 SLC24A4; sodium/potassium/calcium exchanger 4 isoform 1 precursor [KO:K13752 ]
1258 CNGB1; cyclic nucleotide-gated channel beta-1 isoform a [KO:K04952 ]
1260 CNGA2; cyclic nucleotide-gated channel alpha-2 [KO:K04949 ]
1261 CNGA3; cyclic nucleotide-gated channel alpha-3 isoform 1 [KO:K04950 ]
1262 CNGA4; cyclic nucleotide-gated channel alpha-4 [KO:K04951 ]
127064 OR2T12; olfactory receptor 2T12 isoform 1 [KO:K04257 ]
163688 CALML6; calmodulin-like protein 6 isoform 1 [KO:K02183 ]
26246 OR2L2; olfactory receptor 2L2 isoform 1 [KO:K04257 ]
26648 OR7E24; olfactory receptor 7E24 isoform 1 [KO:K04257 ]
26683 OR4F3; olfactory receptor 4F3/4F16/4F29 [KO:K04257 ]
2774 GNAL; guanine nucleotide-binding protein G(olf) subunit alpha isoform 2 [KO:K04633 ]
2782 GNB1; guanine nucleotide-binding protein G(I)/G(S)/G(T) subunit beta-1 isoform 1 [KO:K04536 ]
2788 GNG7; guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit gamma-7 [KO:K04543 ]
283617 OR4K3; olfactory receptor family 4 subfamily K member 3 (gene/pseudogene) [KO:K04257 ]
341152 OR2AT4; olfactory receptor 2AT4 isoform 1 [KO:K04257 ]
343406 OR10R2; olfactory receptor 10R2 isoform 1 [KO:K04257 ]
387815 OR8G3; olfactory receptor family 8 subfamily G member 3 (gene/pseudogene) [KO:K04257 ]
390036 OR52K1; olfactory receptor 52K1 isoform 1 [KO:K04257 ]
390093 OR10A6; olfactory receptor 10A6 isoform 1 [KO:K04257 ]
390326 OR6C76; olfactory receptor 6C76 isoform 1 [KO:K04257 ]
392133 OR10AC1; olfactory receptor family 10 subfamily AC member 1 (gene/pseudogene) [KO:K04257 ]
408 ARRB1; beta-arrestin-1 isoform A [KO:K04439 ]
409 ARRB2; beta-arrestin-2 isoform 1 [KO:K04439 ]
4992 OR1F1; olfactory receptor 1F1 isoform 1 [KO:K04257 ]
5136 PDE1A; dual specificity calcium/calmodulin-dependent 3',5'-cyclic nucleotide phosphodiesterase 1A isoform 2 [KO:K13755 ] [EC:3.1.4.17 ]
5137 PDE1C; dual specificity calcium/calmodulin-dependent 3',5'-cyclic nucleotide phosphodiesterase 1C isoform 2 [KO:K13755 ] [EC:3.1.4.17 ]
5138 PDE2A; cGMP-dependent 3',5'-cyclic phosphodiesterase isoform PDE2A3 [KO:K18283 ] [EC:3.1.4.17 ]
5153 PDE1B; dual specificity calcium/calmodulin-dependent 3',5'-cyclic nucleotide phosphodiesterase 1B isoform 1 [KO:K13755 ] [EC:3.1.4.17 ]
51764 GNG13; guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit gamma-13 [KO:K04547 ]
5566 PRKACA; cAMP-dependent protein kinase catalytic subunit alpha isoform Calpha1 [KO:K04345 ] [EC:2.7.11.11 ]
5567 PRKACB; cAMP-dependent protein kinase catalytic subunit beta isoform 2 [KO:K04345 ] [EC:2.7.11.11 ]
5997 RGS2; regulator of G-protein signaling 2 [KO:K18154 ]
653166 OR1D4; olfactory receptor family 1 subfamily D member 4 [KO:K04257 ]
6543 SLC8A2; sodium/calcium exchanger 2 precursor [KO:K05849 ]
6546 SLC8A1; sodium/calcium exchanger 1 isoform A precursor [KO:K05849 ]
6547 SLC8A3; sodium/calcium exchanger 3 isoform C precursor [KO:K05849 ]
65944 OR2B8; olfactory receptor family 2 subfamily B member 8 (gene/pseudogene) [KO:K04257 ]
801 CALM1; calmodulin-1 isoform 2 [KO:K02183 ]
805 CALM2; calmodulin-2 isoform 2 [KO:K02183 ]
808 CALM3; calmodulin-3 isoform 1 [KO:K02183 ]
810 CALML3; calmodulin-like protein 3 [KO:K02183 ]
81099 OR4F17; olfactory receptor 4F17 isoform 1 [KO:K04257 ]
81169 OR8J2; olfactory receptor family 8 subfamily J member 2 (gene/pseudogene) [KO:K04257 ]
81248 OR52P1; olfactory receptor family 52 subfamily P member 1 (gene/pseudogene) [KO:K04257 ]
81300 OR4P4; olfactory receptor 4P4 isoform 1 [KO:K04257 ]
81399 OR4F16; olfactory receptor 4F3/4F16/4F29 [KO:K04257 ]
81439 OR9H1; olfactory receptor family 9 subfamily H member 1 pseudogene (gene/pseudogene) [KO:K04257 ]
815 CAMK2A; calcium/calmodulin-dependent protein kinase type II subunit alpha isoform 2 [KO:K04515 ] [EC:2.7.11.17 ]
816 CAMK2B; calcium/calmodulin-dependent protein kinase type II subunit beta isoform 1 [KO:K04515 ] [EC:2.7.11.17 ]
817 CAMK2D; calcium/calmodulin-dependent protein kinase type II subunit delta isoform 3 [KO:K04515 ] [EC:2.7.11.17 ]
818 CAMK2G; calcium/calmodulin-dependent protein kinase type II subunit gamma isoform 7 [KO:K04515 ] [EC:2.7.11.17 ]
91860 CALML4; calmodulin-like protein 4 isoform 1 [KO:K02183 ]
Compound
Reference
Authors
Kaupp UB
Title
Olfactory signalling in vertebrates and insects: differences and commonalities.
Journal
Reference
Authors
Peterlin Z, Firestein S, Rogers ME
Title
The state of the art of odorant receptor deorphanization: a report from the orphanage.
Journal
Reference
Authors
Kato A, Touhara K
Title
Mammalian olfactory receptors: pharmacology, G protein coupling and desensitization.
Journal
Reference
Authors
Firestein S.
Title
How the olfactory system makes sense of scents.
Journal
Reference
Authors
Ache BW, Young JM.
Title
Olfaction: diverse species, conserved principles.
Journal
Reference
Authors
Zufall F, Leinders-Zufall T.
Title
The cellular and molecular basis of odor adaptation.
Journal
Reference
Authors
Lodovichi C, Belluscio L
Title
Odorant receptors in the formation of the olfactory bulb circuitry.
Journal
Reference
Authors
Kohout TA, Lefkowitz RJ.
Title
Regulation of G protein-coupled receptor kinases and arrestins during receptor desensitization.
Journal
Reference
Authors
De Palo G, Boccaccio A, Miri A, Menini A, Altafini C
Title
A dynamical feedback model for adaptation in the olfactory transduction pathway.
Journal
Reference
Authors
Zufall F, Munger SD
Title
Receptor guanylyl cyclases in mammalian olfactory function.
Journal
Reference
Authors
Duda T, Sharma RK
Title
Ca2+-modulated ONE-GC odorant signal transduction.
Journal
Related pathway
KO pathway