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排序方式: 共有277条查询结果,搜索用时 31 毫秒
111.
Casalot L Valette O De Luca G Dermoun Z Rousset M de Philip P 《FEMS microbiology letters》2002,214(1):107-112
Desulfovibrio fructosovorans possesses two periplasmic hydrogenases (a nickel-iron and an iron hydrogenase) and a cytoplasmic NADP-dependent hydrogenase. The hydAB genes encoding the periplasmic iron hydrogenase were replaced, in the wild-type strain as well as in single mutants depleted of one of the other two hydrogenases, by the acc1 gene encoding resistance to gentamycin. Molecular characterization and remaining activity measurements of the resulting single and double mutants were performed. All mutated strains exhibited similar growth when H(2) was the electron donor but they grew differently on fructose, lactate or pyruvate as electron donors. Our results indicate that the loss of one enzyme might be compensated by another even though hydrogenases have different localization in the cells. 相似文献
112.
Amarjit S. Naura Rajeshwar Sharma 《Journal of biochemical and molecular toxicology》2009,23(3):193-201
We recently reported the anticarcinogenic potential of hexaammine cobalt(III) chloride, a synthetic complex of cobalt, on diethylnitrosamine (DENA)‐induced carcinogenesis. The present study was conducted to ascertain the possible mode of action of this compound on DENA‐induced hepatocarcinogenesis in male BALB/c mice. Time course evaluation of liver injury markers showed that the low dose of the compound is more effective in ameliorating DENA‐induced changes when administered for longer duration of time. Long‐term exposure of the compound significantly reversed the levels of diacylgylcerol (DAG) and nitric oxide synthase (NOS) induced by DENA, thus suggesting that the compound may hinder the process of chemical carcinogenesis potentially by downregulating the signal transduction mechanism involving DAG and NOS. Furthermore, short‐term intraperitoneal injection of the compound to mice 26 weeks after DENA initiation reduced the cell viability count in preneoplstic liver lesions in a dose‐dependent manner. In conclusion, our results showed that anticarcinogenic effects of hexaammine cobalt(III) chloride result from its influence on signal transduction events mediated through DAG together with its direct cytotoxic action against preneoplastic hepatic lesions induced by DENA in mice. © 2009 Wiley Periodicals, Inc. J Biochem Mol Toxicol 23:193–201, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/jbt.20280 相似文献
113.
Robert Fjellstrom Anna M. McClung A. Robert Shank 《Molecular breeding : new strategies in plant improvement》2006,17(2):149-157
Pi-z is a disease resistance gene that has been effectively used to combat a broad-spectrum of races of the rice blast fungus
Magnaporthe grisea. Although DNA markers have been reported for selection of the Pi2(t) and Pi-z resistance genes at the Pi-z locus, markers that are more tightly linked to the Pi-z locus would benefit rapid and effective cultivar development. Analysis of the publicly available genome sequence of Nipponbare
near the Pi-z locus revealed numerous SSRs that could be converted into markers. Three SSRs on rice PAC AP005659 were found to be very
tightly linked to the Pi-z locus, with one marker, AP5659-3, co-segregating with the Pi-z resistance reaction. The Pi-z factor conferring resistance to two races of blast was mapped to a 57 kb region on the physical map of Nipponbare in a location
where the Pi2(t) gene was physically mapped. Two SSR marker haplotypes were unique for cultivars carrying the Pi-z gene, which indicates these markers are useful for selection of resistance genes at the Pi-z locus in rice germplasm. 相似文献
114.
Di Wang Xiuliang Wang Dapeng Li Feijiu Wang Delin Duan 《Journal of applied phycology》2006,18(6):801-809
Eleven pairs of Undaria pinnatifida (Harv.) Suringar gametophytes were identified with random amplified polymorphic DNA (RAPD) technique. After screening 100 primers, 20 ten-base primers were determined for the RAPD analysis. A total of 312 polymorphic loci were obtained, of which 97.7% were polymorphic. The primer S198 was found to distinguish all the selected Undaria
pinnatifida gametophytes. The genetic distances between each two of the twenty-two U.
pinnatifida gametophytes ranged from 0.080 to 0.428, while the distances to the Laminaria was 0.497 on average. After reexamination, two sequences characterized amplification region (SCAR) markers were successfully converted, which could be applied to U.
pinnatifida germplasm identification. All these results demonstrated the feasibility of applying RAPD markers to germplasm characterization and identification of U. pinnatifida gametophytes, and to provide a molecular basis for Undaria breeding. 相似文献
115.
116.
Wang H Luo K Tan LZ Ren BG Gu LQ Michalopoulos G Luo JH Yu YP 《The Journal of biological chemistry》2012,287(20):16890-16902
Expression of glutathione peroxidase 3 (GPx3) is down-regulated in a variety of human malignancies. Both methylation and deletion of GPx3 gene underlie the alterations of GPx3 expression in prostate cancer. A strong correlation between the down-regulation of GPx3 expression and progression of prostate cancer and the suppression of prostate cancer xenografts in SCID mice by forced expression of GPx3 suggests a tumor suppression role of GPx3 in prostate cancer. However, the mechanism of GPx3-mediated tumor suppression remains unclear. In this report, GPx3 was found to interact directly with p53-induced gene 3 (PIG3). Forced overexpression of GPx3 in prostate cancer cell lines DU145 and PC3 as well as immortalized prostate epithelial cells RWPE-1 increased apoptotic cell death. Expression of GPx3(x73c), a peroxidase-negative OPAL codon mutant, in DU145 and PC3 cells also increased cell death. The induced expression of GPx3 in DU145 and PC3 cells resulted in an increase in reactive oxygen species and caspase-3 activity. These activities were abrogated by either knocking down PIG3 or mutating the PIG3 binding motif in GPx3 or binding interference from a peptide corresponding to PIG3 binding motif in GPx3. In addition, UV-treated RWPE-1 cells underwent apoptotic death, which was partially prevented by knocking down GPx3 or PIG3, suggesting that GPx3-PIG3 signaling is critical for UV-induced apoptosis. Taken together, these results reveal a novel signaling pathway of GPx3-PIG3 in the regulation of cell death in prostate cancer. 相似文献
117.
Many human inherited disorders cause protein N-glycosylation defects, but there are few cellular markers to test gene complementation for such defects. Plasma membrane glycoproteins are potential biomarkers because they may be reduced or even absent in plasma membranes of glycosylation-deficient cells. We combined stable isotope labeling by amino acids in cell culture (SILAC) with linear ion trap mass spectrometry (LTQ Orbitrap(TM)) to identify and quantify membrane proteins from wild-type CHO and glycosylation-deficient CHO (Lec9) cells. We identified 165 underrepresented proteins from 1447 unique quantified proteins, including 18 N-glycosylated plasma membrane proteins. Using various methods, we found that intercellular cell adhesion molecule 1 (ICAM-1) was reduced in Lec9 cells and in fibroblasts from 31 congenital disorder of glycosylation (CDG) patients compared with normal controls. Mannose supplementation of phosphomannose isomerase-deficient CDG-Ib (MPI-CDG) cells and complementation with PMM2 in PMM2-deficient CDG-Ia (PMM2-CDG) cells partially corrected hypoglycosylation based on increased ICAM-1 presence on the plasma membrane. These data indicate that ICAM-1 could be a useful hypoglycosylation biomarker to assess gene complementation of CDG-I patient cells and to monitor improved glycosylation in response to therapeutic drugs. 相似文献
118.
119.
玉米自交系CML470抗南方锈病基因的定位 总被引:2,自引:0,他引:2
南方锈病是我国玉米产区的主要病害,玉米抗病品种的利用是控制其为害的一条最为安全和经济的途径。但是,在我国当前的玉米育种中,所利用的玉米南方锈病基因多来自美国杂交种78599等。为寻找新的南方锈病抗病基因,本研究对CIMMYT自交系CML470的抗性进行了遗传分析。结果发现CML470的抗性由一个显性抗病基因(定名为RppC)控制,该抗病基因被定位于10号染色体短臂端部,位于SSR标记umc1380和umc1291之间,分别与两标记相距3.5 cM和8.8 cM。通过回交,并利用分子标记辅助选择,RppC被转移到了优良自交系昌7-2中。 相似文献
120.
Ming Luo C. Alejandro Velikovsky Xinbo Yang Maqbool A. Siddiqui Xia Hong Joseph J. Barchi Jr. Jeffrey C. Gildersleeve Zeev Pancer Roy A. Mariuzza 《The Journal of biological chemistry》2013,288(32):23597-23606
Variable lymphocyte receptors (VLRs) are leucine-rich repeat proteins that mediate adaptive immunity in jawless vertebrates. VLRs were recently shown to recognize glycans, such as the tumor-associated Thomsen-Friedenreich antigen (TFα; Galβ1–3GalNAcα), with a selectivity rivaling or exceeding that of lectins and antibodies. To understand the basis for TFα recognition by one such VLR (VLRB.aGPA.23), we measured thermodynamic parameters for the binding interaction and determined the structure of the VLRB.aGPA.23-TFα complex to 2.2 Å resolution. In the structure, four tryptophan residues form a tight hydrophobic cage encasing the TFα disaccharide that completely excludes buried water molecules. This cage together with hydrogen bonding of sugar hydroxyls to polar side chains explains the exquisite selectivity of VLRB.aGPA.23. The topology of the glycan-binding site of VLRB.aGPA.23 differs markedly from those of lectins or antibodies, which typically consist of long, convex grooves for accommodating the oligosaccharide. Instead, the TFα disaccharide is sandwiched between a variable loop and the concave surface of the VLR formed by the β-strands of the leucine-rich repeat modules. Longer oligosaccharides are predicted to extend perpendicularly across the β-strands, requiring them to bend to match the concavity of the VLR solenoid. 相似文献