A third photoreceptor-specific GRK found in the retina of Oryzias latipes (Japanese killifish).
We previously reported that the teleost fish medaka (Oryzias latipes, Japanese killifish), possesses two kinds of G protein-coupled receptor kinases (GRKs) in the retina with different localizations: GRK7 (OlGRK-C) in cones and GRK1 (OlGRK-R1) in rods. To further clarify the diversity of teleost photoreceptor GRKs, we sought other medaka GRKs. We found an additional cDNA that encodes a second retina-specific GRK1 (OlGRK-R2). In situ hybridization experiments demonstrated that OlGRK-R2 mRNA is selectively expressed in rods. Sequence analysis of the Fugu rubripes genomic database unveiled a larger diversity of GRKs than previously expected. We also describe the light-dependent regulation of GRK1, a phenomenon that has not been found in other species. Immunocytochemical analysis indicated that OlGRK-R2 is localized in rod outer segments, independent of light condition. OlGRK-R1 is localized in the rod inner segments and synaptic termini of dark-adapted eyes, and moves to rod outer segments after light adaptation. Our studies suggest that the two medaka GRKs are not functionally redundant, and demonstrate a complicated light-dependent regulation of GRK1 in vivo.
Imanishi
Yoshikazu
Y
Department of Earth and Space Science, Graduate School of Science, Osaka University, Toyonaka, Japan.
Hisatomi
Osamu
O
Yamamoto
Shintaro
S
Satoh
Takunori
T
Kotaka
Shuichi
S
Kobayashi
Yuko
Y
Tokunaga
Fumio
F
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D016000:Cluster Analysis; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D054768:G-Protein-Coupled Receptor Kinases / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008027:Light; D008969:Molecular Sequence Data; D009990:Oryzias / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D017948:Retinal Rod Photoreceptor Cells / Q000378:metabolism*; D017422:Sequence Analysis, DNA
D017931:DNA Primers; D018076:DNA, Complementary; D054768:G-Protein-Coupled Receptor Kinases