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排序方式: 共有802条查询结果,搜索用时 15 毫秒
91.
Kiss K Brozik A Kucsma N Toth A Gera M Berry L Vallentin A Vial H Vidal M Szakacs G 《PloS one》2012,7(5):e37378
ABCB6, a member of the adenosine triphosphate-binding cassette (ABC) transporter family, has been proposed to be responsible for the mitochondrial uptake of porphyrins. Here we show that ABCB6 is a glycoprotein present in the membrane of mature erythrocytes and in exosomes released from reticulocytes during the final steps of erythroid maturation. Consistent with its presence in exosomes, endogenous ABCB6 is localized to the endo/lysosomal compartment, and is absent from the mitochondria of cells. Knock-down studies demonstrate that ABCB6 function is not required for de novo heme biosynthesis in differentiating K562 cells, excluding this ABC transporter as a key regulator of porphyrin synthesis. We confirm the mitochondrial localization of ABCB7, ABCB8 and ABCB10, suggesting that only three ABC transporters should be classified as mitochondrial proteins. Taken together, our results challenge the current paradigm linking the expression and function of ABCB6 to mitochondria. 相似文献
92.
Top 10 plant pathogenic bacteria in molecular plant pathology 总被引:7,自引:0,他引:7
Mansfield J Genin S Magori S Citovsky V Sriariyanum M Ronald P Dow M Verdier V Beer SV Machado MA Toth I Salmond G Foster GD 《Molecular Plant Pathology》2012,13(6):614-629
Many plant bacteriologists, if not all, feel that their particular microbe should appear in any list of the most important bacterial plant pathogens. However, to our knowledge, no such list exists. The aim of this review was to survey all bacterial pathologists with an association with the journal Molecular Plant Pathology and ask them to nominate the bacterial pathogens they would place in a 'Top 10' based on scientific/economic importance. The survey generated 458 votes from the international community, and allowed the construction of a Top 10 bacterial plant pathogen list. The list includes, in rank order: (1) Pseudomonas syringae pathovars; (2) Ralstonia solanacearum; (3) Agrobacterium tumefaciens; (4) Xanthomonas oryzae pv. oryzae; (5) Xanthomonas campestris pathovars; (6) Xanthomonas axonopodis pathovars; (7) Erwinia amylovora; (8) Xylella fastidiosa; (9) Dickeya (dadantii and solani); (10) Pectobacterium carotovorum (and Pectobacterium atrosepticum). Bacteria garnering honourable mentions for just missing out on the Top 10 include Clavibacter michiganensis (michiganensis and sepedonicus), Pseudomonas savastanoi and Candidatus Liberibacter asiaticus. This review article presents a short section on each bacterium in the Top 10 list and its importance, with the intention of initiating discussion and debate amongst the plant bacteriology community, as well as laying down a benchmark. It will be interesting to see, in future years, how perceptions change and which bacterial pathogens enter and leave the Top 10. 相似文献
93.
I-Chun Lin Mingtao Liang Tzu-Yu Liu Zhongfan Jia Michael J. Monteiro Istvan Toth 《Bioorganic & medicinal chemistry》2012,20(23):6862-6869
Nanoparticles are commonly engineered with a layer of polymers on the surface used to increase their stability and biocompatibility, as well as providing multifunctional properties. Formulating the nanoparticle size and surface properties with polymers directly affects the way these nanoparticles interact with a biological system. Many previous studies have emphasized the importance of nanoparticle size and surface charge in affecting their toxicity in cells. However, the potential weakness in many of these studies is that the polymer grafting densities on nanoparticles have been disregarded during toxicity evaluation. In the current study, we hypothesized that the density of polymers on nanoparticles will affect their toxicity to cells, especially for nanoparticle cores that are toxic themselves. To address this issue, we synthesized a range of RAFT (reversible addition fragmentation chain transfer) polymers bearing different surface charges and coated them onto silica nanoparticles (SiNPs) with different grafting densities. The in vitro cytotoxicity of these SiNPs was evaluated using the MTT (thiazolyl blue tetrazolium bromide) assay with Caco-2 cells. We found that neutral (biocompatible) polymers with a high grafting density on SiNPs were effective at protecting the cells from the toxicity of the silica core. High cellular toxicity was only observed for cationic polymer-SiNPs, while all other neutral and anionic polymer-SiNPs induced limited cellular toxicity. In contrast, the toxic effects induced by low density polymer-coated SiNPs were mostly attributed to the silica core, while the polymer coatings had a limited contribution. These findings are important indicators for the future evaluation of the toxicological profile of polymer-coated nanoparticles. 相似文献
94.
Charpentier TH Wilder PT Liriano MA Varney KM Pozharski E MacKerell AD Coop A Toth EA Weber DJ 《Journal of molecular biology》2008,382(1):56-73
As part of an effort to inhibit S100B, structures of pentamidine (Pnt) bound to Ca2+-loaded and Zn2+,Ca2+-loaded S100B were determined by X-ray crystallography at 2.15 Å (Rfree = 0.266) and 1.85 Å (Rfree = 0.243) resolution, respectively. These data were compared to X-ray structures solved in the absence of Pnt, including Ca2+-loaded S100B and Zn2+,Ca2+-loaded S100B determined here (1.88 Å; Rfree = 0.267). In the presence and absence of Zn2+, electron density corresponding to two Pnt molecules per S100B subunit was mapped for both drug-bound structures. One Pnt binding site (site 1) was adjacent to a p53 peptide binding site on S100B (± Zn2+), and the second Pnt molecule was mapped to the dimer interface (site 2; ± Zn2+) and in a pocket near residues that define the Zn2+ binding site on S100B. In addition, a conformational change in S100B was observed upon the addition of Zn2+ to Ca2+-S100B, which changed the conformation and orientation of Pnt bound to sites 1 and 2 of Pnt-Zn2+,Ca2+-S100B when compared to Pnt-Ca2+-S100B. That Pnt can adapt to this Zn2+-dependent conformational change was unexpected and provides a new mode for S100B inhibition by this drug. These data will be useful for developing novel inhibitors of both Ca2+- and Ca2+,Zn2+-bound S100B. 相似文献
95.
Glycodelin protein and mRNA is downregulated in human first trimester abortion and partially upregulated in mole pregnancy. 总被引:1,自引:0,他引:1
Bettina Toth Karin Roth Christiane Kunert-Keil Christoph Scholz Sandra Schulze Ioannis Mylonas Klaus Friese Udo Jeschke 《The journal of histochemistry and cytochemistry》2008,56(5):477-485
Glycodelin (Gd) is a major reproductive glycoprotein and a mediator for immunomodulatory effects directed to cellular, humoral, and innate immunity. Human pregnancy depends on a diversity of physiological processes including modulation of the maternal immunosystem. We evaluated the expression of Gd protein and mRNA in first trimester decidual tissue of normal pregnancies and spontaneous abortion and hydatidiform moles. Furthermore, in vitro experiments on endometrial cancer cells to analyze the effect of human chorionic gonadotropin (hCG) on Gd regulation were performed. In decidual tissue of abortion patients, Gd expression was significantly decreased compared with normal gestation, which was confirmed by in situ hybridization. In mole pregnancy, an upregulation of Gd in the first 8 weeks of pregnancy was present. Gd is a main product of decidual tissue in the first trimester of human pregnancy. Reduced Gd expression in abortive pregnancy could lead to an increased activation of the maternal immunosystem, thus causing rejection of the developing fetus. Moreover, Gd expression in endometrial cancer cells in vitro could be stimulated by addition of hCG. Therefore, we speculate that hCG could be one of the factors regulating Gd expression because hCG is downregulated in women with abortion and upregulated in mole pregnancy. In addition, we found a positive feedback loop in Gd and hCG expression in human pregnancy. 相似文献
96.
ATM (ataxia-telangiectasia mutated), ATR (ATM- and Rad3-related) and DNA-PK (DNA-dependent protein kinase), important regulators of genome stability, belong to the PIKK (phosphoinositide 3-kinase-like kinase) family of protein kinases. In the present study, DNA-affinity chromatography was used to identify DNA-binding proteins phosphorylated by these kinases. This resulted in the identification of FUS (fused in sarcoma)/TLS (translocated in liposarcoma) as an in vitro target of the PIKKs. FUS is a member of the Ewing's sarcoma family of proteins that appears to play a role in regulating genome stability, since mice lacking FUS show chromosomal instability and defects in meiosis. The residues in FUS that are phosphorylated in vitro and in vivo were identified, and phospho-specific antibodies were generated to demonstrate that FUS becomes phosphorylated at Ser(42) in vivo, primarily in response to agents that cause DSBs (double-strand breaks). DSB-induced FUS phosphorylation in vivo at Ser(42) requires ATM and not DNA-PK. Although Ser(42) is retained in the oncogenic FUS-CHOP [C/EBP (CCAAT/enhancer-binding protein)-homologous protein 10] fusion generated by a t(12;16)(q13;p11) chromosomal translocation, Ser(42) in FUS-CHOP is not phosphorylated after DNA damage. These results identify FUS as a new target of the ATM-signalling pathway and strengthen the notion that FUS regulates genome stability. 相似文献
97.
Istvan Toth Pavla Simerska Yoshio Fujita 《International journal of peptide research and therapeutics》2008,14(4):333-340
Synthetic lipopeptide vaccines are being increasingly investigated mainly because of the advantages they offer over traditional
vaccines, including safety of use in humans, high specificity in eliciting immune responses, greater purity and large scale/cost-effective
production capacity. Moreover, a number of lipopeptide vaccines designed to possess self-adjuvanting properties have been
developed and tested in vitro and in vivo. Producing high levels of serum-specific antibodies against incorporated peptide
epitopes, they are showing their potential as effective vaccine candidates without the need for a co-administered adjuvant
and/or carrier protein, often associated with undesirable effects in humans. This review presents recent insights on lipopeptide
vaccine research and development, particularly on (1) the influence of the orientation of peptide epitopes and lipids on immune
responses, (2) the use of carbohydrates for vaccine targeting, adjuvanting or as peptide epitope carriers, and (3) synthetic
approaches to highly pure, multi-epitopic vaccine molecules using native chemical ligation techniques. Incorporation of different
types of antigens within the same lipopeptide construct could provide a lipopeptide vaccine candidate suitable for safe and
effective mucosal administration, which is a comfortable way of drug delivery. 相似文献
98.
Toth DJ 《Journal of biological dynamics》2008,2(4):428-448
We model a chemostat containing an age-structured predator and its prey using a linear function for the uptake of substrate by the prey and two different functional responses (linear and Monod) for the consumption of prey by the predator. Limit cycles (LCs) caused by the predator's age structure arise at Hopf bifurcations at low values of the chemostat dilution rate for both model cases. In addition, LCs caused by the predator-prey interaction arise for the case with the Monod functional response. At low dilution rates in the Monod case, the age structure causes cycling at lower values of the inflowing resource concentration and conversely prevents cycling at higher values of the inflowing resource concentration. The results shed light on a similar model by Fussmann et al. [G. Fussmann, S. Ellner, K. Shertzer, and N. Hairston, Crossing the Hopf bifurcation in a live predator-prey system, Science 290 (2000), pp. 1358-1360.], which correctly predicted conditions for the onset of cycling in a chemostat containing an age-structured rotifer population feeding on algal prey. 相似文献
99.
Ndel1 promotes axon regeneration via intermediate filaments 总被引:1,自引:0,他引:1
Toth C Shim SY Wang J Jiang Y Neumayer G Belzil C Liu WQ Martinez J Zochodne D Nguyen MD 《PloS one》2008,3(4):e2014
Failure of axons to regenerate following acute or chronic neuronal injury is attributed to both the inhibitory glial environment and deficient intrinsic ability to re-grow. However, the underlying mechanisms of the latter remain unclear. In this study, we have investigated the role of the mammalian homologue of aspergillus nidulans NudE, Ndel1, emergently viewed as an integrator of the cytoskeleton, in axon regeneration. Ndel1 was synthesized de novo and upregulated in crushed and transected sciatic nerve axons, and, upon injury, was strongly associated with neuronal form of the intermediate filament (IF) Vimentin while dissociating from the mature neuronal IF (Neurofilament) light chain NF-L. Consistent with a role for Ndel1 in the conditioning lesion-induced neurite outgrowth of Dorsal Root Ganglion (DRG) neurons, the long lasting in vivo formation of the neuronal Ndel1/Vimentin complex was associated with robust axon regeneration. Furthermore, local silencing of Ndel1 in transected axons by siRNA severely reduced the extent of regeneration in vivo. Thus, Ndel1 promotes axonal regeneration; activating this endogenous repair mechanism may enhance neuroregeneration during acute and chronic axonal degeneration. 相似文献
100.
We applied native chemical ligation (NCL) method to the synthesis of highly pure lipid-core peptide (LCP) vaccines to attach various peptide epitopes. In the case of the synthesis of LCP vaccine with two different peptide epitopes, LCP moieties having two free Cys and two protected Cys derivatives (S-acetamidemethyl-Cys, (Cys(Acm)), N-methylsulfonylethyloxycarbonyl-Cys (Msc-Cys), or 1,3-thiazolidine-4-carboxylic acid (Thz)) on oligolysine branches were prepared in order to couple two different epitopes by stepwise NCL. It was found that the difficulty in NCL of first two peptide antigen was associated with the steric hindrance. Using Thz instead of Cys(Acm) and Msc-Cys was important to reduce the steric hindrance and improve NCL yield. 相似文献