TY - JOUR
T1 - Rhodopsin kinase activity modulates the amplitude of the visual response in Drosophila
AU - Lee, Seung Jae
AU - Xu, Hong
AU - Montell, Craig
PY - 2004/8/10
Y1 - 2004/8/10
N2 - A feature shared between Drosophila rhodopsin and nearly all other G protein-coupled receptors is agonist-dependent protein phosphorylation. Despite extensive analyses of Drosophila photo-transduction, the identity and function of the rhodopsin kinase (RK) have been elusive. Here, we provide evidence that G protein-coupled receptor kinase 1 (GPRK1), which is most similar to the β-adrenergic receptor kinases, G protein-coupled receptor kinase 2 (GRK2) and GRK3, is the fly RK. We show that GPRKI is enriched in photoreceptor cells, associates with the major Drosophila rhodopsin, Rhl, and phosphorylates the receptor. As is the case with mammalian GRK2 and GRK3, Drosophila GPRK1 includes a C-terminal pleckstrin homology domain, which binds to phosphoinositides and the Gβγ subunit. To address the role of GPRK1, we generated transgenic flies that expressed higher and lower levels of RK activity. Those flies with depressed levels of RK activity displayed a light response with a much larger amplitude than WT. Conversely, the amplitude of the light response was greatly suppressed in transgenic flies expressing abnormally high levels of RK activity. These data point to an evolutionarily conserved role for GPRK1 in modulating the amplitude of the visual response.
AB - A feature shared between Drosophila rhodopsin and nearly all other G protein-coupled receptors is agonist-dependent protein phosphorylation. Despite extensive analyses of Drosophila photo-transduction, the identity and function of the rhodopsin kinase (RK) have been elusive. Here, we provide evidence that G protein-coupled receptor kinase 1 (GPRK1), which is most similar to the β-adrenergic receptor kinases, G protein-coupled receptor kinase 2 (GRK2) and GRK3, is the fly RK. We show that GPRKI is enriched in photoreceptor cells, associates with the major Drosophila rhodopsin, Rhl, and phosphorylates the receptor. As is the case with mammalian GRK2 and GRK3, Drosophila GPRK1 includes a C-terminal pleckstrin homology domain, which binds to phosphoinositides and the Gβγ subunit. To address the role of GPRK1, we generated transgenic flies that expressed higher and lower levels of RK activity. Those flies with depressed levels of RK activity displayed a light response with a much larger amplitude than WT. Conversely, the amplitude of the light response was greatly suppressed in transgenic flies expressing abnormally high levels of RK activity. These data point to an evolutionarily conserved role for GPRK1 in modulating the amplitude of the visual response.
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U2 - 10.1073/pnas.0402205101
DO - 10.1073/pnas.0402205101
M3 - Article
C2 - 15289614
AN - SCOPUS:4143058131
SN - 0027-8424
VL - 101
SP - 11874
EP - 11879
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 32
ER -