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The Protein Pages

Cyclic Nucleotide Cation-gated Channel (CNGA, CNCG)

To see compiled data on further species click on the topics.
To see the reference for the human data click on the data

Editor's Notes from the Literature

Recent update from: 11.07.00

Description
The Cyclic Nucleotide Cation-gated Channel of photoreceptor outer segments is inserted solely into the plasmamembrane (5).The channel is constantly kept open by 5'3'cGMP und closes as cGMP phosphodiesterase hydrolyzes 5'3'cGMP and reduces its concentration. The channel is nonselective for monovalent cations and discriminates bivalent cations for Ca2+. At the end of the visual cascade it converts the light signal, received by the photopigments and amplified by transducin and cGMP phosphodiesterase, into the nerv impuls.

GENE DATA

Exons:

Subunit Rods Cones
subunit 1 10
subunit 2 20

Markers / RFLPs:

Subunit Rods Cones
subunit 1
subunit 2

Transcripts:

Subunit Rods Cones
subunit 1 3.2 kb
subunit 2
Chromosomes with CNCG loci

Assignment:

Subunit Rods Cones
subunit 1 4p12.2 2q11
subunit 2 16q13

Involvement in Retinal Degenerations:

click here to see a compilation of

CNGA1

and CNGA3

Mutations found to underlie

ARRP

Achromatopsia

ARRP has been evaluated in CNGA2

PROTEIN DATA

Subunits:
Subunit Rods Cones
subunit 1 CNCG1 CNGA3, CNCG1'
subunit 2 CNCG2

Amino acids:

Subunit Rods Cones
subunit 1 690 AA
subunit 2 1251 AA

Modifications:

Subunit Rods Cones
subunit 1 phosphorylated at Ser 70 + 77
subunit 2

Mr/ Weight:

Subunit Rods Cones
subunit 1 63 kDa
subunit 2 SDS-PAGE 240 kDa
Mr: 140000

Cofactors:

Subunit Rods Cones
subunit 1 cGMP
subunit 2 Ca2+-Calmodulin
cGMP
PROTEIN DATA

Click on entry to see database record online
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Protein Subtype Locus Species EC-No. Swissprot PIR Prosite
Cyclic Nucleotide-gated Cation Channel subunit 3 CNCG3 Bos taurus EC-
A55251 S43976
Cyclic Nucleotide-gated Cation Channel
CNCG Drosophila melanogaster EC-
S52072
Cyclic Nucleotide-gated Cation Channel subunit 1, rod CNCG1 Gallus gallus EC-
A44842
Cyclic Nucleotide-gated Cation Channel subunit 1, rod CNCG1, CNCG Homo sapiens EC-
A44842
Cyclic Nucleotide-gated Cation Channel subunit 2, rod CNCG2 Homo sapiens EC-
I78560 S32538
Cyclic Nucleotide-gated Cation Channel subunit 3, rod CNCG3L, GAR-1 Homo sapiens EC-
I78559 A57652
Cyclic Nucleotide-gated Cation Channel
CNCG Oryctolagus cuniculus EC-
S35691

GENE DATA

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Gene Subtype Locus Species Genbank Unigene Medline
Cyclic Nucleotide-gated Cation Channel
CNCG Bos taurus X89600 X51604
96009895 94211295 90098076
Cyclic Nucleotide-gated Cation Channel subunit 2, rod CNCG2 Bos taurus X89626
960098959
Cyclic Nucleotide-gated Cation Channel subunit 3 CNCG3 Bos taurus X51604 X89626 X89600
94211295 96009859
Cyclic Nucleotide-gated Cation Channel subunit 1, rod CNCG1 Canis familiaris U83905

Cyclic Nucleotide-gated Cation Channel
CNCG Drosophila melanogaster X89601 S74503
95055396
Cyclic Nucleotide-gated Cation Channel
CNCG Gallus gallus 89598
93264082
Cyclic Nucleotide-gated Cation Channel subunit 1, cone CNCG1 Gallus gallus X89598
93264082
Cyclic Nucleotide-gated Cation Channel subunit 1, rod CNCG1 Gallus gallus X89599
93264082
Cyclic Nucleotide-gated Cation Channel subunit 1, rod CNCG1, CNCG Homo sapiens S42457 M84741 AF002992 NM_000087 Hs.1323 92356211 92210603
Cyclic Nucleotide-gated Cation Channel subunit 2, rod CNCG2 Homo sapiens U58837 NM_001297 AF042498 U18945 Hs.93909 96070429 96338110
Cyclic Nucleotide-gated Cation Channel subunit 3, rod CNCG3L, GAR-1 Homo sapiens U18945
96070429
Cyclic Nucleotide-gated Cation Channel subunit 1, rod CNCG1 Mus musculus M84742 L02635 L02636 U19715 U19717 AI035456 U19716 Mm.23793 93066219 95315239 92210603
Cyclic Nucleotide-gated Cation Channel
CNCG Rattus norvegicus L02634
93066219

GENE LOCUS DATA

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Gene Subtype Locus Species Genome Database Mouse Genome Database OMIM Locus Link
Cyclic Nucleotide-gated Cation Channel subunit 1, rod CNCG1, CNCG Homo sapiens 127557
123825 1259
Cyclic Nucleotide-gated Cation Channel subunit 2, rod CNCG2 Homo sapiens 434397
601793 1258
Cyclic Nucleotide-gated Cation Channel subunit 3, rod CNCG3L, GAR-1 Homo sapiens 434399
600724
Cyclic Nucleotide-gated Cation Channel subunit 1, rod CNCG1 Mus musculus
Cncg
12788

References:
1. Ardell,M.D., Aragon,I., Oliveira,L., Porche,G.E., Burke,E., and Pittler,S.J. The beta subunit of human rod photoreceptor cGMP-gated cation channel is generated from a complex transcription unit. 1996; FEBS Letters. 389: 213-218.
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2. Bharadwaj,A.K., Pittler,S.J., Berson,E.L., and Dryja,T.P. Evaluation Of The GARP Portion Of The Human Rod cGMP-Gated Channel B Subunit Gene In Patients With Autosomal Recessive Retinitis Pigmentosa. 1999; Invest.Ophthalmol.Vis.Sci. 40: S601
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3. Brown,R.L., Gramling,R., Bert,R.J., and Karpen,J.W. Cyclic GMP contact points within the 63-kDa subunit and a 240- kDa associated protein of retinal rod cGMP-activated channels. 1995; Biochemistry. 34: 8365-8370.
Goto Top Link to PudMed
4. Griffin,C.A., Ding,C.L., Jabs,E.W., Hawkins,A.L., Li,X., and Levine,M.A. Human rod cGMP-gated cation channel gene maps to 4p12-- >centromere by chromosomal in situ hybridization. 1993; Genomics. 16: 302-303.
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5. Kaupp,U.B. The cyclic nucleotide-gated channels of vertebrate photoreceptors and olfactory epithelium. 1991; Trends.Neurosci. 14: 150-157.
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6. Liu,M.Y., Li,J., and Yau,K.W. Phosphorylation of the N-terminal domain of human rod cyclic nucleotide-gated channel by protein kinase c and the cAMP- dependent protein kinase. 1994; Invest.Ophthalmol.Vis.Sci. 35 (Suppl.): 1474-1474.
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7. Pittler,S.J., Lee,A.K., Altherr,M.R., Howard,T.A., Seldin,M.F., Hurwitz,R.L., Wasmuth,J.J., and Baehr,W. Primary structure and chromosomal localization of human and mouse rod photoreceptor cGMP-gated cation channel. 1992; J.Biol.Chem. 267: 6257-6262.
Goto Top Link to PudMed
8. Wissinger,B. and Zrenner,E. Identification of the gene encoding the ?-subunit of the cGMP gated cation channel in human cone photoreceptors. 1995; Invest.Ophthalmol.Vis.Sci. Suppl.: S278
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Contact the editor: irpamp@irpa.org 		This site is maintained and edited by
Dr. rer. medic. Markus Preising, Dipl.Biol.
Molecular Genetics Laboratory
Department of Paediatric Ophthalmology, Strabismology and Ophthalmogenetics
University of Regensburg
Head: Prof. Dr. med. Birgit Lorenz