KEGG   PATHWAY: hsa04744Help
Entry
hsa04744                    Pathway                                

Name
Phototransduction - Homo sapiens (human)
Description
Phototransduction is a biochemical process by which the photoreceptor cells generate electrical signals in response to captured photons. The vertebrate cascade starts with the absorption of photons by the photoreceptive pigments, the rhodopsins, which consist of a membrane embedded chromophore, 11-cis-retinal, and a G-protein-coupled receptor, opsin. The photon isomerizes 11-cis-retinal to all-trans-retinal which induces a structural change that activates the opsin. This triggers hydrolysis of cGMP by activating a transducinphosphodiesterase 6 (PDE6) cascade, which results in closure of the cGMP-gated cation channels (CNG) in the plasma membrane and membrane hyperpolarization. The hyperpolarization of the membrane potential of the photoreceptor cell modulates the release of neurotransmitters to downstream cells. Recovery from light involves the deactivation of the light- activated intermediates: photolyzed rhodopsin is phosphorylated by rhodopsin kinase (RK) and subsequently capped off by arrestin; GTP-binding transducin alpha subunit deactivates through a process that is stimulated by RGS9.
Class
Organismal Systems; Sensory system
BRITE hierarchy
Pathway map
hsa04744  Phototransduction
hsa04744

Ortholog table
Disease
H00481  Cone-rod dystrophy and cone dystrophy
H00527  Retinitis pigmentosa
H00787  Congenital stationary night blindness
H00825  Familial flecked retina syndrome
H00837  Leber congenital amaurosis
H00971  Achromatopsia
H00973  Bradyopsia
Other DBs
BSID: 149806
GO: 0009586
Organism
Homo sapiens (human) [GN:hsa]
Gene
6010  RHO; rhodopsin [KO:K04250]
131890  GRK7; G protein-coupled receptor kinase 7 [KO:K00909] [EC:2.7.11.14]
6011  GRK1; G protein-coupled receptor kinase 1 [KO:K00909] [EC:2.7.11.14]
5957  RCVRN; recoverin [KO:K13764]
6295  SAG; S-antigen visual arrestin [KO:K19627]
2780  GNAT2; G protein subunit alpha transducin 2 [KO:K04631]
2779  GNAT1; G protein subunit alpha transducin 1 [KO:K04631]
2782  GNB1; G protein subunit beta 1 [KO:K04536]
2792  GNGT1; G protein subunit gamma transducin 1 [KO:K04548]
8787  RGS9; regulator of G protein signaling 9 [KO:K13765]
5145  PDE6A; phosphodiesterase 6A [KO:K08718] [EC:3.1.4.35]
5158  PDE6B; phosphodiesterase 6B [KO:K13756] [EC:3.1.4.35]
5148  PDE6G; phosphodiesterase 6G [KO:K13759]
3000  GUCY2D; guanylate cyclase 2D, retinal [KO:K12321] [EC:4.6.1.2]
2986  GUCY2F; guanylate cyclase 2F, retinal [KO:K12322] [EC:4.6.1.2]
2978  GUCA1A; guanylate cyclase activator 1A [KO:K08328]
2979  GUCA1B; guanylate cyclase activator 1B [KO:K08328]
9626  GUCA1C; guanylate cyclase activator 1C [KO:K08328]
9187  SLC24A1; solute carrier family 24 member 1 [KO:K13749]
810  CALML3; calmodulin like 3 [KO:K02183]
805  CALM2; calmodulin 2 [KO:K02183]
808  CALM3; calmodulin 3 [KO:K02183]
801  CALM1; calmodulin 1 [KO:K02183]
163688  CALML6; calmodulin like 6 [KO:K02183]
51806  CALML5; calmodulin like 5 [KO:K02183]
91860  CALML4; calmodulin like 4 [KO:K02183]
1259  CNGA1; cyclic nucleotide gated channel alpha 1 [KO:K04948]
1258  CNGB1; cyclic nucleotide gated channel beta 1 [KO:K04952]
Compound
C00076  Calcium cation
C00144  GMP
C00238  Potassium cation
C00305  Magnesium cation
C00376  Retinal
C00942  3',5'-Cyclic GMP
C01330  Sodium cation
C02110  11-cis-Retinal
Reference
  Authors
Yau KW, Hardie RC
  Title
Phototransduction motifs and variations.
  Journal
Cell 139:246-64 (2009)
DOI:10.1016/j.cell.2009.09.029
Reference
  Authors
Koch KW, Duda T, Sharma RK
  Title
Photoreceptor specific guanylate cyclases in vertebrate phototransduction.
  Journal
Mol Cell Biochem 230:97-106 (2002)
Reference
PMID:9803480
  Authors
Jindrova H
  Title
Vertebrate phototransduction: activation, recovery, and adaptation.
  Journal
Physiol Res 47:155-68 (1998)
Reference
  Authors
Ebrey T, Koutalos Y
  Title
Vertebrate photoreceptors.
  Journal
Prog Retin Eye Res 20:49-94 (2001)
DOI:10.1016/S1350-9462(00)00014-8
Reference
  Authors
Pepe IM
  Title
Recent advances in our understanding of rhodopsin and phototransduction.
  Journal
Prog Retin Eye Res 20:733-59 (2001)
DOI:10.1016/S1350-9462(01)00013-1
Reference
  Authors
Kramer RH, Molokanova E
  Title
Modulation of cyclic-nucleotide-gated channels and regulation of vertebrate phototransduction.
  Journal
J Exp Biol 204:2921-31 (2001)
Reference
  Authors
Larhammar D, Nordstrom K, Larsson TA
  Title
Evolution of vertebrate rod and cone phototransduction genes.
  Journal
Philos Trans R Soc Lond B Biol Sci 364:2867-80 (2009)
DOI:10.1098/rstb.2009.0077
Reference
  Authors
Dizhoor AM, Olshevskaya EV, Peshenko IV
  Title
Mg2+/Ca2+ cation binding cycle of guanylyl cyclase activating proteins (GCAPs): role in regulation of photoreceptor guanylyl cyclase.
  Journal
Mol Cell Biochem 334:117-24 (2010)
DOI:10.1007/s11010-009-0328-6
Reference
  Authors
Krizaj D, Copenhagen DR
  Title
Calcium regulation in photoreceptors.
  Journal
Front Biosci 7:d2023-44 (2002)
Reference
PMID:9893707
  Authors
Shichida Y, Imai H
  Title
Visual pigment: G-protein-coupled receptor for light signals.
  Journal
Cell Mol Life Sci 54:1299-315 (1998)
DOI:10.1007/s000180050256
Reference
PMID:9419388
  Authors
Pugh EN Jr, Duda T, Sitaramayya A, Sharma RK
  Title
Photoreceptor guanylate cyclases: a review.
  Journal
Biosci Rep 17:429-73 (1997)
DOI:10.1023/A:1027365520442
Reference
  Authors
Luo DG, Xue T, Yau KW
  Title
How vision begins: an odyssey.
  Journal
Proc Natl Acad Sci U S A 105:9855-62 (2008)
DOI:10.1073/pnas.0708405105
Reference
  Authors
Peshenko IV, Dizhoor AM
  Title
Activation and inhibition of photoreceptor guanylyl cyclase by guanylyl cyclase activating protein 1 (GCAP-1): the functional role of Mg2+/Ca2+ exchange in EF-hand domains.
  Journal
J Biol Chem 282:21645-52 (2007)
DOI:10.1074/jbc.M702368200
Reference
  Authors
Ridge KD, Abdulaev NG, Sousa M, Palczewski K
  Title
Phototransduction: crystal clear.
  Journal
Trends Biochem Sci 28:479-87 (2003)
DOI:10.1016/S0968-0004(03)00172-5
KO pathway
ko04744   

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