Effects of a 50-Hz electric field on sleep quality and life span mediated by ultraviolet (UV)-A/blue light photoreceptor CRYPTOCHROME in Drosophila melanogaster

Although electric fields (EF) exert beneficial effects on animal wound healing and differentiation, the molecular mechanisms of these effects have remained unclear for years. Therefore, we aimed to elucidate the molecular mechanisms underlying these effects in Drosophila melanogaster as a genetic animal model. The sleep quality of wild-type (WT) flies was improved by exposure to a 50-Hz (35 kv/m) constant electric field during the daytime, but not during the night. This effect was undetectable in Cryptochrome mutant (Cryb) flies. Exposure to a 50-Hz electric field under low nutrient conditions elongated the lifespan of male and female WT flies by ~18%, but not of three diferrent Cry mutants and Cry RNAi strains. Metabolome analysis indicated that the adenosine triphosphate (ATP) content was 5-fold higher in intact WT than Cry gene mutant strains exposed to an electric field.A putative magnetoreceptor protein and UV-A/blue light photoreceptor, CRYPTOCHROME (CRY) is involved in electric field receptors in animals. The present findings constitute hitherto unknown genetic evidence of a CRY-based system that is electric-field sensitive in animals.

Millisecond time-resolved serial oscillation crystallography of a blue-light photoreceptor at a synchrotron

The recent development of serial crystallography has popularized time-resolved crystallography as a technique to determine the structure of protein-reaction intermediate states. However, most approaches rely on the availability of thousands to millions of microcrystals. A method is reported here, using monochromatic synchrotron radiation, for the room-temperature collection, processing and merging of X-ray oscillation diffraction data from <100 samples in order to observe the build up of a photoreaction intermediate species. Using this method, we monitored with a time resolution of 63 ms how the population of a blue-light photoreceptor domain in a crystal progressively photoconverts from the dark to the light state. The series of resulting snapshots allows us to visualize in detail the gradual rearrangement of both the protein and chromophore during this process.

The Blue-Light PhotoreceptorSfwc-1Gene Regulates the Phototropic Response and Fruiting-Body Development in the Homothallic AscomyceteSordaria fimicola

ABSTRACTSordaria fimicola, a coprophilous ascomycete, is a homothallic fungus that can undergo sexual differentiation with cellular and morphological changes followed by multicellular tissue development to complete its sexual cycle. In this study, we identified and characterized the blue-light photoreceptor gene inS. fimicola. TheS. fimicolawhite collar-1 photoreceptor (SfWC-1) contains light-oxygen-voltage-sensing (LOV), Per-Arnt-Sim (PAS), and other conserved domains and is homologous to the WC-1 blue-light photoreceptor ofNeurospora crassa. The LOV domain ofSfwc-1was deleted by homologous recombination usingAgrobacterium-mediated protoplast transformation. TheSfwc-1(Δlov)mutant showed normal vegetative growth but produced less carotenoid pigment under illumination. The mutant showed delayed and less-pronounced fruiting-body formation, was defective in phototropism of the perithecial beaks, and lacked the fruiting-body zonation pattern compared with the wild type under the illumination condition. Gene expression analyses supported the light-induced functions of theSfwc-1gene in the physiology and developmental process of perithecial formation inS. fimicola. Moreover, green fluorescent protein (GFP)-tagged SfWC-1 fluorescence signals were transiently strong upon light induction and prominently located inside the nuclei of living hyphae. Our studies focused on the putative blue-light photoreceptor in a model ascomycete and contribute to a better understanding of the photoregulatory functions and networks mediated by the evolutionarily conserved blue-light photoreceptors across diverse fungal phyla.IMPORTANCESordariasp. has been a model for study of fruiting-body differentiation in fungi. Several environmental factors, including light, affect cellular and morphological changes during multicellular tissue development. Here, we created a light-oxygen-voltage-sensing (LOV) domain-deletedSfwc-1mutant to study blue-light photoresponses inSordaria fimicola. Phototropism and rhythmic zonation of perithecia were defective in theSfwc-1(Δlov)mutant. Moreover, fruiting-body development in the mutant was reduced and also significantly delayed. Gene expression analysis and subcellular localization study further revealed the light-induced differential gene expression and cellular responses upon light stimulation inS. fimicola.

Single mutation in a novel bacterial LOV protein yields a singlet oxygen generator

The first blue light photoreceptor isolated from Methylobacterium radiotolerans, a pink-pigmented facultative methylotroph, has been turned into an efficient singlet oxygen generator by introducing a single mutation.