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Full-Text Articles in Neuroscience and Neurobiology
Mutation Of A Tadr Protein Leads To Rhodopsin And Gq-Dependent Retinal Degeneration In Drosophila, Lina Ni, Peiyi Guo, Keith Reddig, Mirna Mitra, Hong-Sheng Li
Mutation Of A Tadr Protein Leads To Rhodopsin And Gq-Dependent Retinal Degeneration In Drosophila, Lina Ni, Peiyi Guo, Keith Reddig, Mirna Mitra, Hong-Sheng Li
Peiyi Guo
The Drosophila photoreceptor is a model system for genetic study of retinal degeneration. Many gene mutations cause fly photoreceptor degeneration, either because of excessive stimulation of the visual transduction (phototransduction) cascade, or through apoptotic pathways that in many cases involve a visual arrestin Arr2. Here we report a gene named tadr (for torn and diminished rhabdomeres), which, when mutated, leads to photoreceptor degeneration through a different mechanism. Degeneration in the tadr mutant is characterized by shrunk and disrupted rhabdomeres, the light sensory organelles of photoreceptor. The TADR protein interacted in vitro with the major light receptor Rh1 rhodopsin, and genetic …
Protein Gq Modulates Termination Of Phototransduction And Prevents Retinal Degeneration, Wen Hu, Didi Wan, Xiaoming Yu, Jinguo Cao, Peiyi Guo, Hong-Sheng Li, Junhai Han
Protein Gq Modulates Termination Of Phototransduction And Prevents Retinal Degeneration, Wen Hu, Didi Wan, Xiaoming Yu, Jinguo Cao, Peiyi Guo, Hong-Sheng Li, Junhai Han
Peiyi Guo
Appropriate termination of the phototransduction cascade is critical for photoreceptors to achieve high temporal resolution and to prevent excessive Ca(2+)-induced cell toxicity. Using a genetic screen to identify defective photoresponse mutants in Drosophila, we isolated and identified a novel Galpha(q) mutant allele, which has defects in both activation and deactivation. We revealed that G(q) modulates the termination of the light response and that metarhodopsin/G(q) interaction affects subsequent arrestin-rhodopsin (Arr2-Rh1) binding, which mediates the deactivation of metarhodopsin. We further showed that the Galpha(q) mutant undergoes light-dependent retinal degeneration, which is due to the slow accumulation of stable Arr2-Rh1 complexes. Our study …