A novel subtype of G-protein-coupled receptor kinase, GRK7, in teleost cone photoreceptors.
Two kinds of retinal cDNA fragments (OIGRK-R and -C) encoding the putative G-protein-coupled receptor kinases (GRKs) were isolated from medaka, Oryzias latipes. OIGRK-R appears to be closely related to the rhodopsin kinase (RK) found in the outer segments of mammalian photoreceptors, but the deduced amino acid sequence of OIGRK-C shows less than 50% identity to those of GRKs known to date, suggesting that OIGRK-C is a novel GRK subtype (GRK7). The mRNA of OIGRK-R is detectable in rods, and that of OIGRK-C is found in all four types of cone photoreceptor. The C-terminal of OIGRK-R has a consensus sequence for farnesylation, whereas, surprisingly, OIGRK-C has a consensus sequence for geranylgeranylation. Our result are consistent with the concept that lower vertebrates have rod- and cone-specific opsin kinases.
Hisatomi
O
O
Department of Earth and Space Science, Graduate School of Science, Osaka University, Japan.
Matsuda
S
S
Satoh
T
T
Kotaka
S
S
Imanishi
Y
Y
Tokunaga
F
F
D000595:Amino Acid Sequence; D000818:Animals; D018076:DNA, Complementary / Q000302:isolation & purification; D017403:In Situ Hybridization / Q000379:methods; D008116:Lizards / Q000502:physiology; D008969:Molecular Sequence Data; D009990:Oryzias / Q000502:physiology*; D010802:Phylogeny; D017346:Protein Serine-Threonine Kinases; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics* / Q000378:metabolism*; D012160:Retina / Q000201:enzymology; D017949:Retinal Cone Photoreceptor Cells / Q000201:enzymology*; D017948:Retinal Rod Photoreceptor Cells; D012455:Salamandridae / Q000502:physiology; D017386:Sequence Homology, Amino Acid
D018076:DNA, Complementary; D020794:Receptor Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases