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51.
Kakizawa S Yamazawa T Chen Y Ito A Murayama T Oyamada H Kurebayashi N Sato O Watanabe M Mori N Oguchi K Sakurai T Takeshima H Saito N Iino M 《The EMBO journal》2012,31(2):417-428
Mobilization of intracellular Ca(2+) stores regulates a multitude of cellular functions, but the role of intracellular Ca(2+) release via the ryanodine receptor (RyR) in the brain remains incompletely understood. We found that nitric oxide (NO) directly activates RyRs, which induce Ca(2+) release from intracellular stores of central neurons, and thereby promote prolonged Ca(2+) signalling in the brain. Reversible S-nitrosylation of type 1 RyR (RyR1) triggers this Ca(2+) release. NO-induced Ca(2+) release (NICR) is evoked by type 1 NO synthase-dependent NO production during neural firing, and is essential for cerebellar synaptic plasticity. NO production has also been implicated in pathological conditions including ischaemic brain injury, and our results suggest that NICR is involved in NO-induced neuronal cell death. These findings suggest that NICR via RyR1 plays a regulatory role in the physiological and pathophysiological functions of the brain. 相似文献
52.
Sakaguchi K Matsuda T Kobayashi T Ohara J Hamaguchi R Abe E Nagano N Hayashi M Ueda M Honda D Okita Y Taoka Y Sugimoto S Okino N Ito M 《Applied and environmental microbiology》2012,78(9):3193-3202
A versatile transformation system for thraustochytrids, a promising producer for polyunsaturated fatty acids and fatty acid-derived fuels, was established. G418, hygromycin B, blasticidin, and zeocin inhibited the growth of thraustochytrids, indicating that multiple selectable marker genes could be used in the transformation system. A neomycin resistance gene (neo(r)), driven with an ubiquitin or an EF-1α promoter-terminator from Thraustochytrium aureum ATCC 34304, was introduced into representatives of two thraustochytrid genera, Aurantiochytrium and Thraustochytrium. The neo(r) marker was integrated into the chromosomal DNA by random recombination and then functionally translated into neo(r) mRNA. Additionally, we confirmed that another two genera, Parietichytrium and Schizochytrium, could be transformed by the same method. By this method, the enhanced green fluorescent protein was functionally expressed in thraustochytrids. Meanwhile, T. aureum ATCC 34304 could be transformed by two 18S ribosomal DNA-targeting vectors, designed to cause single- or double-crossover homologous recombination. Finally, the fatty acid Δ5 desaturase gene was disrupted by double-crossover homologous recombination in T. aureum ATCC 34304, resulting in an increase of dihomo-γ-linolenic acid (C(20:3n-6)) and eicosatetraenoic acid (C(20:4n-3)), substrates for Δ5 desaturase, and a decrease of arachidonic acid (C(20:4n-6)) and eicosapentaenoic acid (C(20:5n-3)), products for the enzyme. These results clearly indicate that a versatile transformation system which could be applicable to both multiple transgene expression and gene targeting was established for thraustochytrids. 相似文献
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Eguchi K Manabe I Oishi-Tanaka Y Ohsugi M Kono N Ogata F Yagi N Ohto U Kimoto M Miyake K Tobe K Arai H Kadowaki T Nagai R 《Cell metabolism》2012,15(4):518-533
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55.
Goda HM Ushigusa K Ito H Okino N Narimatsu H Ito M 《Biochemical and biophysical research communications》2008,375(4):441-446
We report here the molecular cloning, expression and characterization of a novel endo-alpha-N-acetylgalactosaminidase, classified into the GH101 family, from Enterococcus faecalis (endo-EF). The recombinant endo-EF was found to catalyze the liberation of core1-disaccharides (Galbeta1-3GalNAc) from core1-pNP (Galbeta1-3GalNAcalpha-pNP) like other GH101 family enzymes. However, endo-EF seems to differ in specificity from the GH101 enzymes reported to date, because it was able to release trisaccharides from core2-pNP (Galbeta1-3[GlcNAcbeta1-6]GalNAcalpha-pNP) and tetrasaccharides from Gal-core2-pNP (Galbeta1-3[Galbeta1-3GlcNAcbeta1-6]GalNAcalpha-pNP). Interestingly, the enzyme could transfer not only core1-disaccharides but also core2-trisaccharides to alkanols generating alkyl-oligosaccharides. Endo-EF should facilitate O-glycoprotein research. 相似文献
56.
Mitsuomi Hirashima Yumiko Kashio Nozomu Nishi Akira Yamauchi Tada-Atsu Imaizumi Toshiro Kageshita Naoki Saita Takanori Nakamura 《Glycoconjugate journal》2002,19(7-9):593-600
We first cloned galectin-9 (Gal-9)/ecalectin as a T cell-derived eosinophil chemoattractant. Gal-9 plays a role in not only accumulation but also activation of eosinophils in experimental allergic models and human allergic patients, because Gal-9 induces eosinophil chemoattraction in vitro and in vivo and activates eosinophils in many aspects. Gal-9 requires divalent galactoside-binding activity but not the linker peptide of Gal-9 to exhibit its biological functions, and an unidentified matrix metalloproteinase is involved in the release of Gal-9. Our recent studies also showed that Gal-9 has other functions, such as cell differentiation, aggregation, adhesion, and death. Now, we and other groups are on the way of investigating the regulation and function of Gal-9 in a variety of physiological and pathological conditions. In this article, we will show the possible role of Gal-9 in physiological and pathological conditions by using our recent findings. Published in 2004. 相似文献
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58.
1. The enzyme–substrate complex of yeast cytochrome c peroxidase is used as a sensitive, specific and accurate spectrophotometric H2O2 indicator. 2. The cytochrome c peroxidase assay is suitable for use with subcellular fractions from tissue homogenates as well as with pure enzyme systems to measure H2O2 generation. 3. Mitochondrial substrates entering the respiratory chain on the substrate side of the antimycin A-sensitive site support the mitochondrial generation of H2O2. Succinate, the most effective substrate, yields H2O2 at a rate of 0.5nmol/min per mg of protein in state 4. H2O2 generation is decreased in the state 4→state 3 transition. 4. In the combined mitochondrial–peroxisomal fraction of rat liver the changes in the mitochondrial generation of H2O2 modulated by substrate, ADP and antimycin A are followed by parallel changes in the saturation of the intraperoxisomal catalase intermediate. 5. Peroxisomes supplemented with uric acid generate extraperoxisomal H2O2 at a rate (8.6–16.4nmol/min per mg of protein) that corresponds to 42–61% of the rate of uric acid oxidation. Addition of azide increases these H2O2 rates by a factor of 1.4–1.7. 6. The concentration of cytosolic uric acid is shown to vary during the isolation of the cellular fractions. 7. Microsomal fractions produce H2O2 (up to 1.7nmol/min per mg of protein) at a ratio of 0.71–0.86mol of H2O2/mol of NADP+ during the oxidation of NADPH. H2O2 is also generated (6–25%) during the microsomal oxidation of NADH (0.06–0.025mol of H2O2/mol of NAD+). 8. Estimation of the rates of production of H2O2 under physiological conditions can be made on the basis of the rates with the isolated fractions. The tentative value of 90nmol of H2O2/min per g of liver at 22°C serves as a crude approximation to evaluate the biochemical impact of H2O2 on cellular metabolism. 相似文献
59.
Deoxyribonucleic Acid Damage by Monofunctional Mitomycins and Its Repair in Escherichia coli 总被引:3,自引:1,他引:2
Exposure of Escherichia coli to the antibiotic mitomycin C (MTC) at a concentration of 0.5 mug/ml caused cross-linkage between complementary strands of deoxyribonucleic acid (DNA). Derivatives of mitomycin, 7-methoxymitosene (7-MMT) and decarbamoyl mitomycin C (DCMTC), at a level as high as 20 mug/ml formed no cross-links between DNA strands. Ultraviolet light-sensitive mutants of E. coli K-12 bearing uvrA, uvrB, uvrC, or recA mutations were more sensitive to the lethal action of 7-MMT and of DCMTC than was the wild-type strain. Treatment of wild-type cells with these antibiotics resulted in the production of single-strand breaks in DNA, which were repaired upon incubation in a growth medium. Such breaks in DNA were not produced in the uvrA and the uvrB mutants. In the uvrC mutant, single-strand breaks were produced by 7-MMT or by DCMTC, but these breaks were not repaired upon incubation. These results are discussed in connection with the mechanism for removal of pyrimidine dimers in ultraviolet-irradiated bacteria. 相似文献
60.
Reduction of mitochondrial components by durohydroquinone 总被引:7,自引:0,他引:7