A novel U(VI)-containing polytungstate (U-POW) tetramer, {KNa[K(UO)Cl(OH)(γ-SiWO)]}·ca66HO (), was synthesized using the Keggin-type precursor [γ-SiWO] and UO(NO). was further characterized by single-crystal X-ray diffraction, FT-IR, Raman spectroscopy, solid-state diffuse reflection spectroscopy, ICP-OES, ESI-MS, TGA, and PXRD. The central {K(UO)Cl(OH)} chromophore was constructed dexterously from four uranyl, four halves of K ions, 5.
View Article and Find Full Text PDFCell Stress Chaperones
July 2018
In this study, we studied the effect of 2.0 GHz radio frequency electromagnetic field (RF-EMF) and 50 Hz extremely low frequency electromagnetic field (ELF-EMF) exposure on prion generation and propagation using two budding yeast strains, NT64C and SB34, as model organisms. Under exposure to RF-EMF or ELF-EMF, the de novo generation and propagation of yeast prions [URE3] were elevated in both strains.
View Article and Find Full Text PDFIn this study, we investigated the transcriptional response to 50 Hz extremely low frequency electromagnetic field (ELF-EMF) and 2.0 GHz radio frequency electromagnetic field (RF-EMF) exposure by Illumina sequencing technology using budding yeast as the model organism. The transcription levels of 28 genes were upregulated and those of four genes were downregulated under ELF-EMF exposure, while the transcription levels of 29 genes were upregulated and those of 24 genes were downregulated under RF-EMF exposure.
View Article and Find Full Text PDFTemperature is an important factor in research on the biological effects of extremely low-frequency electromagnetic field (ELF-EMF), but interactions between ELF-EMF and temperature remain unknown. The effects of ELF-EMF (50 Hz, 3 mT) on the lifespan, locomotion, heat shock response (HSR), and oxidative stress (OS) of Canton-Special (CS) and mutant w1118 flies were investigated at 25°C and 35°C (thermal stress). Results showed that thermal stress accelerated the death rates of CS and w1118 flies, shortened their lifespan, and influenced their locomotion rhythm and activity.
View Article and Find Full Text PDFInitiation of eukaryotic DNA replication requires phosphorylation of the MCM complex by Dbf4-dependent kinase (DDK), composed of Cdc7 kinase and its activator, Dbf4. We report here that budding yeast Rif1 (Rap1-interacting factor 1) controls DNA replication genome-wide and describe how Rif1 opposes DDK function by directing Protein Phosphatase 1 (PP1)-mediated dephosphorylation of the MCM complex. Deleting RIF1 partially compensates for the limited DDK activity in a cdc7-1 mutant strain by allowing increased, premature phosphorylation of Mcm4.
View Article and Find Full Text PDFMutat Res Genet Toxicol Environ Mutagen
December 2013
Extremely low frequency electromagnetic field (ELF-EMF) exposure is attracting increased attention as a possible disease-inducing factor. The in vivo effects of short-term and long-term ELF-EMF exposure on male Drosophila melanogaster were studied using transcriptomic analysis for preliminary screening and QRT-PCR for further verification. Transcriptomic analysis indicated that 439 genes were up-regulated and 874 genes were down-regulated following short-term exposures and that 514 genes were up-regulated and 1206 genes were down-regulated following long-term exposures (expression >2- or <0.
View Article and Find Full Text PDFDNA replication in Saccharomyces cerevisiae proceeds according to a temporal program. We have investigated the role of the telomere-binding Ku complex in specifying late replication of telomere-proximal sequences. Genome-wide analysis shows that regions extending up to 80 kb from telomeres replicate abnormally early in a yku70 mutant.
View Article and Find Full Text PDFUre2 is the protein determinant of the [URE3] prion phenotype in Saccharomyces cerevisiae and consists of a flexible N-terminal prion-determining domain and a globular C-terminal glutathione transferase-like domain. Overexpression of the type I Hsp40 member Ydj1 in yeast cells has been found to result in the loss of [URE3]. However, the mechanism of prion curing by Ydj1 remains unclear.
View Article and Find Full Text PDFThe Saccharomyces cerevisiae protein Ure2 functions as a regulator of nitrogen metabolism and as a glutathione-dependent peroxidase. Ure2 also has the characteristics of a prion, in that it can undergo a heritable conformational change to an aggregated state; the prion form of Ure2 loses the regulatory function, but the enzymatic function appears to be maintained. A number of factors are found to affect the prion properties of Ure2, including mutation and expression levels of molecular chaperones, and the effect of these factors on structure and stability are being investigated.
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