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951.
Abstract The synthesis of carbocyclic nucleosides, cis-9-[4-(1,2-dihydroxyethyl)-cyclopent-2-enyl]guanine (3) and cis-2-amino-6-cyclopropylamino-9-[4-(1,2-dihydroxyethyl)-cyclopent-2-enyl]guanine (4), was achieved from cyclopentadiene (5) in five and six steps, respectively. This route involves a hetero Diels-Alder reaction and a Pd(0)-catalyzed coupling reaction. 相似文献
952.
Jeonghoon Han Eun-Ji Won Dae-Sik Hwang Jae-Sung Rhee Il-Chan Kim Jae-Seong Lee 《Comparative biochemistry and physiology. Toxicology & pharmacology : CBP》2013,158(2):91-100
Glutathione S-transferases (GSTs; EC 2.5.1.18) are major enzymes that function in Phase II detoxification reactions by catalyzing the conjugation of reduced glutathione through cysteine thiol. In this study, we cloned and sequenced four GST genes from the monogonont rotifer Brachionus koreanus. The domain regions of four Bk-GSTs showed a high similarity to those of other species. In addition, to evaluate the potential of GST genes as an early warning signal for oxidative stress, we exposed sublethal concentrations of copper (Cu) to B. koreanus and measured glutathione (GSH) contents and several antioxidant enzymes such as glutathione S-transferase (GST), glutathione peroxidase (GPx; EC 1.11.1.9), and glutathione reductase (GR; EC 1.8.1.7). The reactive oxygen species (ROS) at 12 h and 24 h after copper exposure increased significantly. GSH contents however did not increase significantly and even it decreased at 0.24 mg/L at 12 h. The activities of several antioxidant enzymes, particularly GPx and GR, showed a dramatic increase in 0.24 mg/L of CuCl2. Messenger RNAs of each Bk-GST showed different patterns of modulations according to GST types, and particularly, Bk-GST-omega, Bk-GST-sigma, and Bk-GST zeta genes were highly sensitive to Cu. These results indicate that Bk-GSTs, functioning as one of the enzymatic defense mechanisms particularly in the early stage of oxidative stress response, were induced by Cu exposure. This also suggests that these genes and related enzymes have a potential as biomarkers for a more sensitive initial stress response. 相似文献
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Kim KY Kim JY Sung YY Jung WH Kim HY Park JS Cheon HG Rhee SD 《Biochemical and biophysical research communications》2011,(4):584-589
The calcium-sensing receptor (CaR) plays an integral role in calcium homeostasis and the regulation of other cellular functions including cell proliferation and cytoskeletal organisation. The multifunctional nature of the CaR is manifested through ligand-dependent stimulation of different signalling pathways that are also regulated by partner binding proteins. Following a yeast two-hybrid library screen using the intracellular tail of the CaR as bait, we identified several novel binding partners including the focal adhesion protein, testin. Testin has not previously been shown to interact with cell surface receptors. The sites of interaction between the CaR and testin were mapped to the membrane proximal region of the receptor tail and the second zinc-finger of LIM domain 1 of testin, the integrity of which was found to be critical for the CaR-testin interaction. The CaR-testin association was confirmed in HEK293 cells by coimmunoprecipitation and confocal microscopy studies. Ectopic expression of testin in HEK293 cells stably expressing the CaR enhanced CaR-stimulated Rho activity but had no effect on CaR-stimulated ERK signalling. These results suggest an interplay between the CaR and testin in the regulation of CaR-mediated Rho signalling with possible effects on the cytoskeleton. 相似文献
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Kyung June Yim In-Tae Cha Tae Woong Whon Hae-Won Lee Hye Seon Song Kil-Nam Kim Young-Do Nam Sung-Jae Lee Jin-Woo Bae Sung-Keun Rhee Jong-Soon Choi Myung-Ji Seo Seong Woon Roh Daekyung Kim 《Antonie van Leeuwenhoek》2014,105(1):73-79
A novel, red-pigmented and coccoid haloarchaeon, designated strain CBA1101T, was isolated from a marine sediment. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain CBA1101T is most closely related to the genus Halococcus in the family Halobacteriaceae. Strain CBA1101T had a highest 16S rRNA gene sequence similarity of 98.4 % with Halococcus dombrowskii DSM 14522T, followed by 93.7–98.3 % with sequences of other type strains in the genus Halococcus. The RNA polymerase subunit B′ gene sequence similarity of strain CBA1101T with that of Halococcus qingdaonensis JCM 13587T is 89.5 % and lower with those of other members of the genus Halococcus. Strain CBA1101T was observed to grow at 25–40 °C, pH 6.0–9.0 and in the presence of 15–30 % (w/v) NaCl, with optimal growth at 35–40 °C, pH 7.0 and with 20 % NaCl. The cells of strain CBA1101T are Gram-negative and did not lyse in distilled water. The major polar lipids were identified as phosphatidylglyerol, phosphatidylglycerol phosphate methyl ester, sulfated diglycosyl diether, unidentified phospholipids and unidentified glycolipids. The genomic DNA G+C content was determined 66.0 mol%. The DNA–DNA hybridization experiment showed that there was less than 40 % relatedness between strain CBA1101T and the reference species in the genus Halococcus. Based on this polyphasic taxonomic analysis, strain CBA1101T is considered to represent a new species in the genus Halococcus, for which the name Halococcus sediminicola sp. nov. is proposed. The type strain is CBA1101T (=JCM 18965T = CECT 8275T). 相似文献
957.
Hyun Ju Oh Jung Eun Park Eun Jung Park Min Jung Kim Geon A Kim Sang Ho Rhee Sang Hyun Lim Sung Keun Kang Byeong Chun Lee 《Development, growth & differentiation》2014,56(9):595-604
In several laboratory animals and humans, adipose tissue‐derived mesenchymal stem cells (ASC) are of considerable interest because they are easy to harvest and can generate a huge proliferation of cells from a small quantity of fat. In this study, we investigated: (i) the expression patterns of reprogramming‐related genes in porcine ASC; and (ii) whether ASC can be a suitable donor cell type for generating cloned pigs. For these experiments, ASC, adult skin fibroblasts (AF) and fetal fibroblasts (FF) were derived from a 4‐year‐old female miniature pig. The ASC expressed cell‐surface markers characteristic of stem cells, and underwent in vitro differentiation when exposed to specific differentiation‐inducing conditions. Expression of DNA methyltransferase (DNMT)1 in ASC was similar to that in AF, but the highest expression of the DNMT3B gene was observed in ASC. The expression of OCT4 was significantly higher in FF and ASC than in AF (P < 0.05), and SOX2 showed significantly higher expression in ASC than in the other two cell types (P < 0.05). After somatic cell nuclear transfer (SCNT), the development rate of cloned embryos derived from ASC was comparable to the development of those derived using FF. Total cell numbers of blastocysts derived using ASC and FF were significantly higher than in embryos made with AF. The results demonstrated that ASC used for SCNT have a potential comparable to those of AF and FF in terms of embryo in vitro development and blastocyst formation. 相似文献
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Effector proteins are virulence factors that promote pathogenesis by interfering with various cellular events and are delivered directly into host cells by the secretion systems of many Gram‐negative bacteria. Type III effector protein XOO4466 from the plant pathogen Xanthomonas oryzae pv. oryzae (XopQXoo) and XopQ homologs from other phytopathogens have been predicted to be nucleoside hydrolases based on their sequence similarities. However, despite such similarities, recent structural and functional studies have revealed that XopQXoo does not exhibit the expected activity of a nucleoside hydrolase. On the basis of the conservation of a Ca2+ coordination shell of a ribose‐binding site and the spacious active site in XopQXoo, we hypothesized that a novel compound containing a ribosyl moiety could serve as a substrate for XopQXoo. Here, we report the crystal structure of XopQXoo in complex with adenosine diphosphate ribose (ADPR), which is involved in regulating cytoplasmic Ca2+ concentrations in eukaryotic cells. ADPR is bound to the active site of XopQXoo with its ribosyl end tethered to the Ca2+ coordination shell. The binding of ADPR is further stabilized by interactions mediated by hydrophobic residues that undergo ligand‐induced conformational changes. These data showed that XopQXoo is capable of binding a novel chemical bearing a ribosyl moiety, thereby providing the first step toward understanding the functional role of XopQXoo. Proteins 2014; 82:2910–2914. © 2014 Wiley Periodicals, Inc. 相似文献