Molecular basis of amplification in Drosophila phototransduction: roles for G protein, phospholipase C, and diacylglycerol kinase
| Autor: | R C, Hardie, F, Martin, G W, Cochrane, M, Juusola, P, Georgiev, P, Raghu |
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| Rok vydání: | 2002 |
| Předmět: |
Diacylglycerol Kinase
Rhodopsin Saccharomyces cerevisiae Proteins Phosphatidylinositol Diacylglycerol-Lyase Down-Regulation Dark Adaptation Heterotrimeric GTP-Binding Proteins Membrane Potentials Fungal Proteins Adenosine Triphosphate Drosophila melanogaster GTP-Binding Proteins Sensory Thresholds Type C Phospholipases Mutation Animals GTP-Binding Protein alpha Subunits Gq-G11 Photoreceptor Cells Invertebrate Vision Ocular Transcription Factors |
| Zdroj: | Neuron. 36(4) |
| ISSN: | 0896-6273 |
| Popis: | In Drosophila photoreceptors, the amplification responsible for generating quantum bumps in response to photoisomerization of single rhodopsin molecules has been thought to be mediated downstream of phospholipase C (PLC), since bump amplitudes were reportedly unaffected in mutants with greatly reduced levels of either G protein or PLC. We now find that quantum bumps in such mutants are reduced approximately 3- to 5-fold but are restored to near wild-type values by mutations in the rdgA gene encoding diacylglycerol kinase (DGK) and also by depleting intracellular ATP. The results demonstrate that amplification requires activation of multiple G protein and PLC molecules, identify DGK as a key enzyme regulating amplification, and implicate diacylglycerol as a messenger of excitation in Drosophila phototransduction. |
| Databáze: | OpenAIRE |
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