KEGG   PATHWAY: ko04740Help
Entry
ko04740                     Pathway                                

Name
Olfactory transduction
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
ko04740  Olfactory transduction
ko04740

Ortholog table
Other DBs
BSID: 498
GO: 0007608
Orthology
K04257  olfactory receptor
K04633  guanine nucleotide-binding protein G(olf) subunit alpha
K04536  guanine nucleotide-binding protein G(I)/G(S)/G(T) subunit beta-1
K04543  guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit gamma-7
K04547  guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit gamma-13
K08043  adenylate cyclase 3 [EC:4.6.1.1]
K04949  cyclic nucleotide gated channel alpha 2
K04951  cyclic nucleotide gated channel alpha 4
K04952  cyclic nucleotide gated channel beta 1
K19497  anoctamin-2
K12321  guanylate cyclase 2D/E [EC:4.6.1.2]
K04950  cyclic nucleotide gated channel alpha 3
K19695  neurocalcin delta
K07376  cGMP-dependent protein kinase 1 [EC:2.7.11.12]
K19477  cGMP-dependent protein kinase 2 [EC:2.7.11.12]
K05849  solute carrier family 8 (sodium/calcium exchanger)
K13752  solute carrier family 24 (sodium/potassium/calcium exchanger), member 4
K00910  beta-adrenergic-receptor kinase [EC:2.7.11.15]
K04439  beta-arrestin
K18154  regulator of G-protein signaling 2
K04345  protein kinase A [EC:2.7.11.11]
K04515  calcium/calmodulin-dependent protein kinase (CaM kinase) II [EC:2.7.11.17]
K02183  calmodulin
K13755  calcium/calmodulin-dependent 3',5'-cyclic nucleotide phosphodiesterase [EC:3.1.4.17]
K18283  cGMP-dependent 3',5'-cyclic phosphodiesterase [EC:3.1.4.17]
Compound
C00020  AMP
C00076  Calcium cation
C00144  GMP
C00238  Potassium cation
C00575  3',5'-Cyclic AMP
C00698  Cl-
C00942  3',5'-Cyclic GMP
C01330  Sodium cation
Reference
  Authors
Kaupp UB
  Title
Olfactory signalling in vertebrates and insects: differences and commonalities.
  Journal
Nat Rev Neurosci 11:188-200 (2010)
DOI:10.1038/nrn2789
Reference
  Authors
Peterlin Z, Firestein S, Rogers ME
  Title
The state of the art of odorant receptor deorphanization: a report from the orphanage.
  Journal
J Gen Physiol 143:527-42 (2014)
DOI:10.1085/jgp.201311151
Reference
  Authors
Kato A, Touhara K
  Title
Mammalian olfactory receptors: pharmacology, G protein coupling and desensitization.
  Journal
Cell Mol Life Sci 66:3743-53 (2009)
DOI:10.1007/s00018-009-0111-6
Reference
  Authors
Firestein S.
  Title
How the olfactory system makes sense of scents.
  Journal
Nature 413:211-8 (2001)
DOI:10.1038/35093026
Reference
  Authors
Ache BW, Young JM.
  Title
Olfaction: diverse species, conserved principles.
  Journal
Neuron 48:417-30 (2005)
DOI:10.1016/j.neuron.2005.10.022
Reference
  Authors
Zufall F, Leinders-Zufall T.
  Title
The cellular and molecular basis of odor adaptation.
  Journal
Chem Senses 25:473-81 (2000)
DOI:10.1093/chemse/25.4.473
Reference
  Authors
Lodovichi C, Belluscio L
  Title
Odorant receptors in the formation of the olfactory bulb circuitry.
  Journal
Physiology (Bethesda) 27:200-12 (2012)
DOI:10.1152/physiol.00015.2012
Reference
  Authors
Kohout TA, Lefkowitz RJ.
  Title
Regulation of G protein-coupled receptor kinases and arrestins during receptor desensitization.
  Journal
Mol Pharmacol 63:9-18 (2003)
DOI:10.1124/mol.63.1.9
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
Biophys J 102:2677-86 (2012)
DOI:10.1016/j.bpj.2012.04.040
Reference
  Authors
Zufall F, Munger SD
  Title
Receptor guanylyl cyclases in mammalian olfactory function.
  Journal
Mol Cell Biochem 334:191-7 (2010)
DOI:10.1007/s11010-009-0325-9
Reference
  Authors
Duda T, Sharma RK
  Title
Ca2+-modulated ONE-GC odorant signal transduction.
  Journal
FEBS Lett 583:1327-30 (2009)
DOI:10.1016/j.febslet.2009.03.036

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