Retina International's Scientific Newsletter

	Retina International's Scientific Newsletter
Editor's Notes from literature on Colour Pigment (BCP, GCP, RCP)

Recent update from: 18.12.1999

RCP, GCP

Notes

Pathogenic mechanisms blue cone monochromatism: deletion in the locus control region or genetic rearrangements
Deletion of exon 4 in a isolated RCP

Species: Homo sapiens

See also:

Chromosomal localisation	in man:
	in mouse:

Gene Data

Exons:

Primers:

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE:
	calculated:

Reference: (5)

RCP, GCP

Notes

Pro 307 Leu mutation
Diminished absorption of light and activation of GNT
Cause of color vision deficiency
Mutation does not impair transport of cone pigment to the cell membrane
P307 of cone pigment is homologue of P291 in RHO
The mutation disrupts the RAl binding pocket without disruption the helical conformation
Comparable to Pro 347 mutants
Spectral tuning by Ala 180, Phe 277 and Ala 285

Species: recombinant

See also:

Chromosomal localisation	in man:
	in mouse:

Gene Data

Exons:

Primers:

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE:
	calculated:

Reference: (8)

BCP, Blue

Notes

Species: Homo sapiens

See also:

Chromosomal localisation	in man: 7q22-qter
	in mouse:

Gene Data

Exons:

Primers:

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE:
	calculated:

Reference: (6)

BCP, Blue

Notes

Species: Homo sapiens

See also:

Chromosomal localisation	in man: 7q31-q35
	in mouse:

Gene Data

Exons:

Primers:

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE:
	calculated:

Reference: (4)

BCP, Blue

Notes

Species: Homo sapiens

See also:

Chromosomal localisation	in man:
	in mouse:

Gene Data

gDNA: 17 kb

Exons: 5

Primers:

Protein Data

Aminoacids: 348 AA

Molecularweight	on SDS-PAGE:
	calculated:

Reference: (7)

BCP, blue

Notes

Transgenic mice with 3.8 and 1.1 kb 5' sequence of human blue cone pigment
Transgene expression in S-cones and INL
Reporter-gene positive INL cells = Bipolars
Both constructs resulted in expression in S-cones like in wildtype animals
Cones make 5% of photoreceptors
Two cone types in mouse retina (middle wave = 510 nm, near UV= 370 nm)

Species: Mus musculus

See also:

Chromosomal localisation	in man:
	in mouse:

Gene Data

Exons:

Primers:

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE:
	calculated:

Reference: (1)

RCP, GCP, red, green

Notes

Two highly expressed isoforms with cyclophilin and RBD4 domains
Cyclophilin-II identical to RanBP2, which binds small GTP binding protein Ran
Cyclophilin domain does not bind opsin directly, it stabilizes the interaction to RBD4 domain
Binding is GTP independent
No binding with RHO and BCP due to cyclophilin PPIase activity
No selection of phosphorylated forms
Cyclophilin functions as a chaperon and foldase

Species:

See also: RanBP2

Chromosomal localisation	in man:
	in mouse:

Gene Data

Exons:

Primers:

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE:
	calculated:

Reference: (3)

RCP, GCP, red, green

Notes

Majority of red-green defects associated with deletion of GCP or formation of red-green or green-red 5'-hybrids
Protan defects are associated with red-green hybrids, rarely with green-red hybrids
Deuteranopia associated with complete GCP deletion and green-red fusions
Exon 5 mutations define red-green status of a hybrid

Species: Homo sapiens

See also:

Chromosomal localisation	in man:
	in mouse:

Gene Data

Exons:

Primers: GCP, RCP

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE:
	calculated:

Reference: (2)

RCP, GCP, red, green

Notes

Lack of glycosylation does neither impair the ability to absorb light of the appropriate wavelength nor to activate GNT
Glycosylation and palmitoylation are not required for the formation of cone visual pigments
Mutant: N32S green opsin
X-linked cone opsins are not palmitoylated unlike RHO
C203R mutatnt is unglycosylated, aberrantly folded and deficient in transport to the cell membrane
Lack of glycosylation in C203R seems to be an effect of misfolding and not vice versa

Species: Homo sapiens

See also:

Chromosomal localisation	in man:
	in mouse:

Gene Data

Exons:

Primers:

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE:
	calculated:

Reference: (9)

Online Reference

RCP, GCP, red, green

Notes

41% identity to RHO
red green 96% identity
red green/blue 43% identity
green genes vary in copy number, single red gene
red to green in head to tail tandem array
integral membrane proteins, in plasma and disc membrane
absorption maxima: 420 nm blue, 530 nm green, 560 nm red
RCP, GCP exons 2-6 correspond to RHO exons
TATA-box

Species: Homo sapiens

See also:

Chromosomal localisation	in man:
	in mouse:

Gene Data

cDNA:

Exons: 6

Primers:

Protein Data

Aminoacids: 364 AA

Molecularweight	on SDS-PAGE: 47,1 kDa
	calculated:

Reference: (7)

RCP, GCP, red, green

Notes

Only expressed RCP-GCP hybrids cause deuteranomaly
Most males have one RCP and two GCP, rarely more than three GCP
LCR between 3.1 and 3.7 kb 5' of the RCP gene transcription initiation site

Species: Homo sapiens

See also:

Chromosomal localisation	in man:
	in mouse:

Gene Data

Exons:

Primers: RCP, GCP

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE:
	calculated:

Reference: (11)

RCP, GCP, red, green

Notes

anomalous trichromates: 3 types of cones, one with altered pigment
Dichromats: 2 types of cones
red-green coulour defects: 8% of all male caucasian
Dichromacy due to unequal exchanges or gene conversion producing red-green hybrids

Species: Homo sapiens

See also:

Chromosomal localisation	in man: Xq22-q28
	in mouse:

Gene Data

Exons: 6

Primers:

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE:
	calculated:

Reference: (6)

RCP, GCP, red, green

Notes

Identification of cis-acting elements involved in expression
Postive element between -130 and TATA-box
LCR does not enhance transcription in transient transfection but binds factors that recognize proximal promotor region
4 critical elements:
1. GA-box (-130 to -113), positive effect, binds SP1 and SP3
2. PCE1 (-109 to -93), photoreceptor specificity
3. Region reducing promotor activity
4. Conserved region -49 to -40
  1. Unlikely NRL activity

Species: Homo sapiens

See also:

Chromosomal localisation	in man:
	in mouse:

Gene Data

Exons:

Primers:

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE:
	calculated:

Reference: (10)

References:

1. Chen, J., Tucker, C.L., Woodford, B., Szel, A., Lem, J., Gianella Borradori, A., Simon, M.I., and Bogenmann, E. The human blue opsin promoter directs transgene expression in short-wave cones and bipolar cells in the mouse retina. 1994; Proc.Natl.Acad.Sci.U.S.A. 91: 2611 - 2615.
Goto Top

2. Deeb, S.S., Lindsey, D.T., Hibiya, Y., Sanocki, E., Winderickx, J., Teller, D.Y., and Motulsky, A.G. Genotype-phenotype relationships in human red/green color-vision defects: molecular and psychophysical studies. 1992; Am.J.Hum.Genet. 51: 687 - 700.
Goto Top

3. Ferreira, P.A., Nakayama, T.A., Pak, W.L., and Travis, G.H. Cyclophilin-related protein RanBP2 acts as chaperone for red/green opsin. 1996; Nature. 383: 637 - 640.
Goto Top Link to PudMed

4. Fitzgibbon, J., Appukuttan, B., Gayther, S., Wells, D., Delhanty, J., and Hunt, D.M. Localisation of the human blue cone pigment gene to chromosome band 7q31.3-32. 1994; Hum.Genet. 93: 79 - 80.
Goto Top Link to PudMed

5. Ladekjaer Mikkelsen, A.S., Rosenberg, T., and Jorgensen, A.L. A new mechanism in blue cone monochromatism. 1996; Hum.Genet. 98: 403 - 408.
Goto Top Link to PudMed

6. Nathans, J., Piantanida, T.P., Eddy, R.L., Shows, T.B., and Hogness, D.S. Molecular genetics of inherited variation in human color vision. 1986; Science. 232: 203 - 210.
Goto Top Link to PudMed

7. Nathans, J., Thomas, D., and Hogness, D.S. Molecular genetics of human color vision: the genes encoding blue, green, and red pigments. 1986; Science. 232: 193 - 202.
Goto Top Link to PudMed

8. Ostrer, H. and Kazmi, M.A. Mutation of a conserved proline disrupts the retinal-binding pocket of the X-linked cone opsins. 1997; Mol.Vis. 3: 16
Goto Top Link to PudMed
Human Mutation Online

9. Ostrer, H., Pullarkat, R.K., and Kazmi, M.A. Glycosylation and palmitoylation are not required for the formation of the X-linked cone opsin visual pigments. 1998; Mol.Vis. 4:28: 28
Goto Top Link to PudMed

10. Shaaban, S.A. and Deeb, S.S. Functional analysis of the promoters of the human red and green visual pigment genes. 1998; Invest.Ophthalmol.Vis.Sci. 39: 885 - 896.
Goto Top Link to PudMed

11. Yamaguchi, T., Motulsky, A.G., and Deeb, S.S. Visual pigment gene structure and expression in human retinae. 1997; Hum.Mol.Genet. 6: 981 - 990.
Goto Top Link to PudMed

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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