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91.
Cloning and expression analysis of a Parkinson's disease gene, uch-L1, and its promoter in zebrafish
Son OL Kim HT Ji MH Yoo KW Rhee M Kim CH 《Biochemical and biophysical research communications》2003,312(3):601-607
Three genes, alpha-synuclein, parkin, and ubiquitin C-terminal hydrolase L1 (UCH-L1), have been associated with inherited forms of Parkinson's disease (PD), although their in vivo functions have remained largely unknown. To develop an animal model for the molecular study of PD, we cloned zebrafish uch-L1 cDNA and its gene promoter. Sequence analysis revealed that the zebrafish Uch-L1 is highly homologous (79%) to the human UCH-L1, which is a member of the deubiquitinating enzymes. By whole-mount in situ hybridization, we examined the spatiotemporal expression of uch-L1 mRNA in developing zebrafish embryos. The uch-L1 mRNAs are detected in neuronal cells at the first day of embryo development. The expression domain of uch-L1 overlaps with that of tyrosine hydroxylase, a molecular marker for dopaminergic neurons, in the ventral diencephalon, an equivalent structure to the substantia nigra where PD progresses in human. To further analyze the tissue-specific regulation of uch-L1 gene expression, we also tested its gene promoter activity and showed a preferential neuronal expression in transient transgenic zebrafish embryos. These results suggest that uch-L1 may have an important role in the development of neuronal cells in early embryos as well as in the degeneration and disease of neuronal cells in late adult brain. 相似文献
92.
Freely suspended and Ca-alginate-immobilized cells of Pimelobacter sp. were used for degradation of pyridine. When the pyridine concentration was up to 2 g l–1, freely suspended cells completely degraded pyridine regardless of the initial cell concentrations used. However, when the pyridine concentration increased to 4 g l–1, the initial cell concentration in freely suspended cell culture should be higher than 1.5 g dry cell weight l–1 for complete degradation of pyridine. In addition, a freely suspended cell culture with a high initial cell concentration resulted in a high volumetric pyridine-degradation rate, suggesting the potential use of immobilized cells for pyridine-degradation. When the immobilized cells were used for pyridine-degradation, neither specific pyridine-degradation rate nor tolerance against pyridine was improved. However, a high volumetric pyridine-degradation rate in the range 0.082–0.129 g l–1 hr–1 could be achieved by the immobilized cells because of the high cell concentration. Furthermore, when the immobilized cells were reused in degrading pyridine at a concentration of 2–4 g l–1 they did not lose their pyridine-degrading activity for 2 weeks. Taken together, the data obtained here showed the feasibility of using immobilized cells for pyridine-degradation. 相似文献
93.
A bacterium which has phospholipase A1 activity was isolated from soil. It is aerobic, motile, oxidase-negative and has flagella. The G+C content of the DNA was 58.1 mol%. The major isoprenoids of cell was were Q-8 and MK-8. The main cellular fatty acids were saturated straight chain (n-16) and cyclic (17:) fatty acids. Based on its morphological, physiological and chemotaxonomic characteristics, this organism was placed in the genusSerratia. Nutritional factors affecting enzyme production were explored. Xylose and ammonium sulfate were the best carbon and nitrogen sources, respectively. Ferrous ions exerted a considerable positive effect on enzyme production. The optimal pH and temperature for phospholipase A1 production were 7.0 and 30°C, respectively. 相似文献
94.
Silkworm hemolymph (SH) was found to exhibit anti-apoptotic activities in mammalian and insect cell systems. An anti-apoptotic mechanism of SH was investigated in a staurosporine-induced HeLa cell using flow cytometry, caspase assay, Immunoblot, and Immunochemistry. The addition of 5% SH to the medium resulted in lower intracellular activities of caspase-3 and caspase-9 after 0.6 μM of staurosporine treatment; however, SH did not directly inhibit the activities of those enzymes. This suggests SH inhibits the event upstream of these caspase activation steps, such as mitochondrial level events. We found from Immunoblot and Immunochemistry that cytochrome c release from the mitochondria was blocked by SH. SH also inhibited Bax translocation to the mitochondria. On the contrary, SH did not block the apoptosis when Bax is not involved in promoting apoptosis. With these results, we propose that SH protects mitochondria from apoptosis signal via blocking Bax translocation, and the subsequent apoptotic events are then inhibited. The inhibition of apoptosis using SH and its components may lead to new approaches for the minimization of cell death during commercial animal cell cultures. 相似文献
95.
Aluminium oxide (Al2O3) has widely been used for catalysts, insulators, and composite materials for diverse applications. Herein, we demonstrated if γ‐Al2O3 was useful as a luminescence support material for europium (Eu) (III) activator ion. The hydrothermal method and post‐thermal treatment at 800°C were employed to synthesize Eu(III)‐doped γ‐Al2O3 nanofibre structures. Luminescence characteristics of Eu(III) ions in Al2O3 matrix were fully understood by taking 2D and 3D‐photoluminescence imaging profiles. Various sharp emissions between 580 to 720 nm were assigned to the 5D0→7FJ (J = 0, 1, 2, 3, 4) transitions of Eu(III) activators. On the basis of X‐ray diffraction crystallography, Auger elemental mapping and the asymmetry ratio, Eu(III) ions were found to be well doped into the γ‐Al2O3 matrix at a low (1 mol%) doping level. A broad emission at 460 nm was substantially increased upon higher (2 mol%) Eu(III) doping due to defect creation. The first 3D photoluminescence imaging profiles highlight detailed understanding of emission characteristics of Eu(III) ions in Al oxide‐based phosphor materials and their potential applications. 相似文献
96.
Lewis G. Watt Sam Crawshaw Sun-Ju Rhee Alex M. Murphy Toms Canto John P. Carr 《PLoS pathogens》2020,16(12)
The cucumber mosaic virus (CMV) 2b viral suppressor of RNA silencing (VSR) is a potent counter-defense and pathogenicity factor that inhibits antiviral silencing by titration of short double-stranded RNAs. It also disrupts microRNA-mediated regulation of host gene expression by binding ARGONAUTE 1 (AGO1). But in Arabidopsis thaliana complete inhibition of AGO1 is counterproductive to CMV since this triggers another layer of antiviral silencing mediated by AGO2, de-represses strong resistance against aphids (the insect vectors of CMV), and exacerbates symptoms. Using confocal laser scanning microscopy, bimolecular fluorescence complementation, and co-immunoprecipitation assays we found that the CMV 1a protein, a component of the viral replicase complex, regulates the 2b-AGO1 interaction. By binding 2b protein molecules and sequestering them in P-bodies, the 1a protein limits the proportion of 2b protein molecules available to bind AGO1, which ameliorates 2b-induced disease symptoms, and moderates induction of resistance to CMV and to its aphid vector. However, the 1a protein-2b protein interaction does not inhibit the ability of the 2b protein to inhibit silencing of reporter gene expression in agroinfiltration assays. The interaction between the CMV 1a and 2b proteins represents a novel regulatory system in which specific functions of a VSR are selectively modulated by another viral protein. The finding also provides a mechanism that explains how CMV, and possibly other viruses, modulates symptom induction and manipulates host-vector interactions. 相似文献
97.
Ji-Ye Rhee Seong-Hee Lee Adya Prasad Singh Gap-Chae Chung Sung-Ju Ahn 《Physiologia plantarum》2007,130(2):177-184
The figleaf gourd ( Cucurbita ficifolia Bouché) root system has the ability to take up water and nutrients at low soil temperatures, and in the present paper, we attempt to reveal some of the molecular mechanisms behind this low-temperature tolerance. Exposure of figleaf gourd root system to low temperature induced accumulation of H2 O2 along the plasma membrane but not in the cytoplasm. H+ -ATPase (EC 3.6.1.35) activity of isolated root plasma membranes and root hydraulic conductivity ( Lpr ) were largely insensitive to externally applied H2 O2 . However, using bromocresol purple, it was shown that the acidification of the medium surrounding the root was strongly inhibited with low temperature- and H2 O2 -treated roots. Addition of catalase (EC 1.11.1.6) to the root medium during low-temperature exposure led to a recovery of H+ -efflux along the root surface and increased Lpr , demonstrating the importance of an H2 O2 detoxification system in the root cells. Additional evidence for an increased Lpr was obtained by the Fenton reaction wherein a warming of the solution increased the activity of the detoxification system. All available evidence suggests that the ability of figleaf gourd root system to maintain a low level of H2 O2 in the cytoplasm and to detoxify reactive oxygen species is related to the maintenance of water transport activity at low temperatures. 相似文献
98.
99.
Jung WS Hong CK Lee S Kim CS Kim SJ Kim SI Rhee S 《The Journal of biological chemistry》2007,282(11):8414-8423
Inulin fructotransferase (IFTase), a member of glycoside hydrolase family 91, catalyzes depolymerization of beta-2,1-fructans inulin by successively removing the terminal difructosaccharide units as cyclic anhydrides via intramolecular fructosyl transfer. The crystal structures of IFTase and its substrate-bound complex reveal that IFTase is a trimeric enzyme, and each monomer folds into a right-handed parallel beta-helix. Despite variation in the number and conformation of its beta-strands, the IFTase beta-helix has a structure that is largely reminiscent of other beta-helix structures but is unprecedented in that trimerization is a prerequisite for catalytic activity, and the active site is located at the monomer-monomer interface. Results from crystallographic studies and site-directed mutagenesis provide a structural basis for the exolytic-type activity of IFTase and a functional resemblance to inverting-type glycosyltransferases. 相似文献
100.
Mijin Oh Horim Lee Young-Kook Kim Jin-Wu Nam Je-Keun Rhee Byoung-Tak Zhang V. Narry Kim Ilha Lee 《Journal of Plant Biology》2007,50(5):562-572
MicroRNAs (miRNAs) and small interfering RNAs (siRNAs) are two major classes of small non-coding RNAs with important roles
in the regulation of gene expression, such as mRNA degradation and translational repression, heterochromatin formation, genome
defense against transposons and viruses in eukaryotes. MiRNA- and siRNA-directed processes have emerged as a regulatory mechanism
for growth and development in both animals and plants. To identify small RNAs that might be involved in vernalization, a process
accelerating flowering brought on by a long period of cold, we generated a library of small RNAs from Arabidopsis that had
been subject to vernalization. From the analysis of the library, 277 small RNAs were identified. They were distributed throughout
all the five chromosomes. While the vast majority of small RNA genes locate on intergenic regions, others locate on repeat-rich
regions, centromeric regions, transposon-related genes, and protein-coding genes. Five of them were mapped to convergent overlapping
gene pairs. Two-hundred and forty of them were novel endogenous small RNAs that have not been cloned yet from plants grown
under normal conditions and other environmental stresses. Seven putative miRNAs were up- or down-regulated by vernalization.
In conclusion, many small RNAs were identified from vernalized Arabidopsis and some of these identified small RNAs may play
roles in plant responses to vernalization. 相似文献