The dynamic nature of genome organization impacts critical nuclear functions including the regulation of gene expression, replication, and DNA damage repair. Despite significant progress, the mechanisms responsible for reorganization of the genome in response to cellular stress, such as aberrant DNA replication, are poorly understood. Here, we show that fission yeast cells carrying a mutation in the DNA-binding protein Sap1 show defects in DNA replication progression and genome stability and display extensive changes in genome organization.
View Article and Find Full Text PDFThe effect of the oral administration of mimosa tannin (MMT) on the rat intra-hippocampal antioxidant ability was examined. Wistar rats at the age of 6 weeks were reared for 8 weeks with the rodent diet (RD) consisting of 0.1 g/kg of MMT (RD-MMT).
View Article and Find Full Text PDFThe hydroxyl- and superoxide-radical-eliminating ability of water-soluble biosubstances was examined by ESR combined with the spin-trapping method, indicating a median inhibitory dose, ID(h)(50) (mM) and id(h)(50) (mg/mL) for the hydroxyl radical, and ID(s)(50) (mM) and id(s)(50) (mg/mL) for the superoxide radical. Both the 1/[ID(h)(50) (mM)] and 1/[ID(s)(50) (mM)] values of selected biosubstances were linearly related to the second-order rate constant, k(2) (M(-1) s(-1)), defined for the reaction between biosubstances and the radicals in a logarithmic presentation. The result indicates that ID(h)(50) (mM) and ID(s)(50) (mM) are suitable parameters for both types of radical-eliminating ability.
View Article and Find Full Text PDFTy1, a long terminal repeat retrotransposon of Saccharomyces, is structurally and functionally related to retroviruses. However, a differentiating aspect between these retroelements is the diversity of the replication strategies used by long terminal repeat retrotransposons. To understand the structural organization of cis-acting elements present on Ty1 genomic RNA from the GAG region that control reverse transcription, we applied chemoenzymatic probing to RNA/tRNA complexes assembled in vitro and to the RNA in virus-like particles.
View Article and Find Full Text PDFSchizosaccharomyces pombe cells switch mating type by replacing genetic information at the expressed mat1 locus with sequences copied from mat2-P or mat3-M silent donor loci. The choice of donor locus is dictated by cell type, such that mat2 is the preferred donor in M cells and mat3 is the preferred donor in P cells. Donor choice involves a recombination-promoting complex (RPC) containing Swi2 and Swi5.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
September 2009
Transposable elements impact genome function by altering gene expression and causing chromosome rearrangements. As a result, organisms have evolved mechanisms, such as RNA-interference, to minimize the level of transposition. However, organisms without the conserved RNAi pathways, like Saccharomyces cerevisiae, must use other mechanisms to prevent transposon movement.
View Article and Find Full Text PDFWe have isolated a polylactide or poly(L-lactic acid) (PLA)-degrading bacterium, Amycolatopsis sp. strain K104-1, and purified PLA depolymerase (PLD) from the culture fluid of the bacterium. Here, we cloned and expressed the pld gene encoding PLD in Streptomyces lividans 1326 and characterized a recombinant PLD (rPLD) preparation.
View Article and Find Full Text PDFBackground: The effects of the non-impairing, H(1)-receptor antagonist fexofenadine were investigated in in vivo mouse models of eosinophilia and systemic anaphylaxis.
Methods: Eosinophilia was investigated in C57BL/6 mice (n=5 per group) infected with Trichinella spiralis, with and without administration of fexofenadine HCl (5, 10 and 20 mg/kg/day). Eosinophilia was also studied, with and without fexofenadine administration, in mice with a congenital mast-cell deficiency (W/W(v)) and controls (+/+).