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Full-Text Articles in Medicine and Health Sciences
Human Cryptochrome Exhibits Light-Dependent Magnetosensitivity, Lauren Foley, Robert Gegear, Steven Reppert
Human Cryptochrome Exhibits Light-Dependent Magnetosensitivity, Lauren Foley, Robert Gegear, Steven Reppert
Robert J. Gegear
Humans are not believed to have a magnetic sense, even though many animals use the Earth's magnetic field for orientation and navigation. One model of magnetosensing in animals proposes that geomagnetic fields are perceived by light-sensitive chemical reactions involving the flavoprotein cryptochrome (CRY). Here we show using a transgenic approach that human CRY2, which is heavily expressed in the retina, can function as a magnetosensor in the magnetoreception system of Drosophila and that it does so in a light-dependent manner. The results show that human CRY2 has the molecular capability to function as a light-sensitive magnetosensor and reopen an area …
The Fly Camta Transcription Factor Potentiates Deactivation Of Rhodopsin, A G Protein-Coupled Light Receptor, Junhai Han, Ping Gong, Keith Reddig, Mirna Mitra, Peiyi Guo, Hong-Sheng Li
The Fly Camta Transcription Factor Potentiates Deactivation Of Rhodopsin, A G Protein-Coupled Light Receptor, Junhai Han, Ping Gong, Keith Reddig, Mirna Mitra, Peiyi Guo, Hong-Sheng Li
Peiyi Guo
Control of membrane-receptor activity is required not only for the accuracy of sensory responses, but also to protect cells from excitotoxicity. Here we report the isolation of two noncomplementary fly mutants with slow termination of photoresponses. Genetic and electrophysiological analyses of the mutants revealed a defect in the deactivation of rhodopsin, a visual G protein-coupled receptor (GPCR). The mutant gene was identified as the calmodulin-binding transcription activator (dCAMTA). The known rhodopsin regulator Arr2 does not mediate this visual function of dCAMTA. A genome-wide screen identified five dCAMTA target genes. Of these, overexpression of the F box gene dFbxl4 rescued the …
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 …