Entry
Name
Olfactory transduction - Equus caballus (horse)
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
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Pathway map
Ortholog table
Other DBs
Organism
Equus caballus (horse) [GN:
ecb ]
Gene
100069568 LOW QUALITY PROTEIN: putative olfactory receptor 52P1 [KO:K04257 ]
100058237 LOW QUALITY PROTEIN: olfactory receptor 2A1/2A42-like [KO:K04257 ]
100147445 LOW QUALITY PROTEIN: putative olfactory receptor 5AK3 [KO:K04257 ]
100069592 LOW QUALITY PROTEIN: putative olfactory receptor 52P1 [KO:K04257 ]
111774238 LOW QUALITY PROTEIN: putative olfactory receptor 10D4 [KO:K04257 ]
100071953 LOW QUALITY PROTEIN: putative olfactory receptor 10D4 [KO:K04257 ]
100066804 LOW QUALITY PROTEIN: putative olfactory receptor 5AK3 [KO:K04257 ]
100050622 GNAL; guanine nucleotide-binding protein G(olf) subunit alpha isoform X2 [KO:K04633 ]
100061395 GNB1; guanine nucleotide-binding protein G(I)/G(S)/G(T) subunit beta-1 [KO:K04536 ]
100059736 GNG7; guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit gamma-7 [KO:K04543 ]
100065327 GNG13; guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit gamma-13 [KO:K04547 ]
100055033 CNGA4; cyclic nucleotide-gated cation channel alpha-4 isoform X1 [KO:K04951 ]
100061333 CNGA3; cyclic nucleotide-gated cation channel alpha-3 [KO:K04950 ]
100063742 SLC24A4; sodium/potassium/calcium exchanger 4 isoform X1 [KO:K13752 ]
100064138 CAMK2G; calcium/calmodulin-dependent protein kinase type II subunit gamma isoform X13 [KO:K04515 ] [EC:2.7.11.17 ]
100071654 CAMK2A; calcium/calmodulin-dependent protein kinase type II subunit alpha isoform X1 [KO:K04515 ] [EC:2.7.11.17 ]
100072618 CAMK2D; calcium/calmodulin-dependent protein kinase type II subunit delta isoform X6 [KO:K04515 ] [EC:2.7.11.17 ]
100146368 CAMK2B; calcium/calmodulin-dependent protein kinase type II subunit beta isoform X1 [KO:K04515 ] [EC:2.7.11.17 ]
100064482 CALML6; LOW QUALITY PROTEIN: calmodulin-like protein 6 [KO:K02183 ]
100054082 PDE1A; calcium/calmodulin-dependent 3',5'-cyclic nucleotide phosphodiesterase 1A isoform X2 [KO:K13755 ] [EC:3.1.4.17 ]
100064711 PDE1B; calcium/calmodulin-dependent 3',5'-cyclic nucleotide phosphodiesterase 1B isoform X2 [KO:K13755 ] [EC:3.1.4.17 ]
100070015 PDE1C; calcium/calmodulin-dependent 3',5'-cyclic nucleotide phosphodiesterase 1C isoform X4 [KO:K13755 ] [EC:3.1.4.17 ]
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
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