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101.
Redox signaling: thiol chemistry defines which reactive oxygen and nitrogen species can act as second messengers 总被引:10,自引:0,他引:10
Except for the role of NO in the activation of guanylate cyclase, which is well established, the involvement of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in signal transduction remains controversial, despite a large body of evidence suggestive of their participation in a variety of signaling pathways. Several problems have limited their acceptance as signaling molecules, with the major one being the difficulty in identifying the specific targets for each pathway and the chemical reactions supporting reversible oxidation of these signaling components, consistent with a second messenger role for ROS and RNS. Nevertheless, it has become clear that cysteine residues in the thiolate (i.e., ionized) form that are found in some proteins can be specific targets for reaction with H2O2 and RNS. This review focuses on the chemistry of the reversible oxidation of those thiolates, with a particular emphasis on the critical thiolate found in protein tyrosine phosphatases as an example. hydrogen peroxide; thiolate; nitrosothiol; nitric oxide; signal transduction 相似文献
102.
New insights into porcine-human synteny conservation 总被引:1,自引:0,他引:1
Niels J. Larsen Stefan Marklund Kemba A. Kelly Massoud Malek Christopher K. Tuggle Martine Yerle Max F. Rothschild 《Mammalian genome》1999,10(5):488-491
Eleven genes were mapped to the porcine genome with the aim of improving the human-porcine comparative gene map. Five of
these genes were from regions of the human genome painted by porcine chromosomal probes; of these, two mapped to chromosomes
not expected from the painting results. Among the six genes from human regions not painted by porcine chromosomal probes,
three genes did not map where expected by the principle of parsimony. Several of the gene assignments indicate the existence
of small regions of conserved synteny not detected by heterologous chromosome painting, especially in telomeric regions. We
have also detected new rearrangements in gene order within the regions of correspondence between human Chromosome (HSA) 15
and porcine Chromosome (SSC) 1 as well as between HSA4 and SSC8.
Received: 30 September 1998 / Accepted: 3 December 1998 相似文献
103.
An efficient solubilization buffer for plant proteins focused in immobilized pH gradients 总被引:2,自引:0,他引:2
The solubilization of a large array of proteins before electrophoresis itself is a very critical point for proteomic analyses. We compared the efficiency of several different solubilization buffers. From this work, we defined a very efficient solubilization buffer, including two chaotropes, two reducing agents (R2), two detergents (D2), and two kinds of carrier ampholytes in combination. This so-called R2D2 buffer (5 M urea, 2 M thiourea, 2% 3-[(3-cholamidopropyl) dimethyl-ammonio]-1-propane-sulfonate, 2% N-decyl-N,N-dimethyl-3-ammonio-1-propane-sulfonate, 20 mM dithiothreitol, 5 mM Tris(2-carboxyethyl) phosphine, 0.5% carrier ampholytes 4-6.5, 0.25% carrier ampholytes 3-10) proved to be very efficient for a large range of different samples and allowed us to obtain two-dimensional gels of high resolution and quality. 相似文献
104.
105.
Yalaoui S Huby T Franetich JF Gego A Rametti A Moreau M Collet X Siau A van Gemert GJ Sauerwein RW Luty AJ Vaillant JC Hannoun L Chapman J Mazier D Froissard P 《Cell host & microbe》2008,4(3):283-292
Infection of hepatocytes by Plasmodium falciparum sporozoites requires the host tetraspanin CD81. CD81 is also predicted to be a coreceptor, along with scavenger receptor BI (SR-BI), for hepatitis C virus. Using SR-BI-knockout, SR-BI-hypomorphic and SR-BI-transgenic primary hepatocytes, as well as specific SR-BI-blocking antibodies, we demonstrate that SR-BI significantly boosts hepatocyte permissiveness to P. falciparum, P. yoelii, and P. berghei entry and promotes parasite development. We show that SR-BI, but not the low-density lipoprotein receptor, acts as a major cholesterol provider that enhances Plasmodium infection. SR-BI regulates the organization of CD81 at the plasma membrane, mediating an arrangement that is highly permissive to penetration by sporozoites. Concomitantly, SR-BI upregulates the expression of the liver fatty-acid carrier L-FABP, a protein implicated in Plasmodium liver-stage maturation. These findings establish the mechanistic basis of the CD81-dependent Plasmodium sporozoite invasion pathway. 相似文献
106.
Pelletier L Ozlü N Hannak E Cowan C Habermann B Ruer M Müller-Reichert T Hyman AA 《Current biology : CB》2004,14(10):863-873
BACKGROUND: The centrosome is composed of a centriole pair and pericentriolar material (PCM). By marking the site of PCM assembly, the centrioles define the number of centrosomes present in the cell. The PCM, in turn, is responsible for the microtubule (MT) nucleation activity of centrosomes. Therefore, in order to assemble a functional bipolar mitotic spindle, a cell needs to control both centriole duplication and PCM recruitment. To date, however, the molecular mechanisms that govern these two processes still remain poorly understood. RESULTS: Here we show that SPD-2 is a novel component of the C. elegans centrosome. SPD-2 localizes to the centriole throughout the cell cycle and accumulates on the PCM during mitosis. We show that SPD-2 requires SPD-5 for its accumulation on the PCM and that in the absence of SPD-2, centrosome assembly fails. We further show that centriole duplication is also defective in spd-2(RNAi) embryos, but not in spd-5(RNAi) embryos, where PCM recruitment is efficiently blocked. CONCLUSIONS: Taken together, our results suggest that SPD-2 may link PCM recruitment and centriole duplication in C. elegans. SPD-2 shares homology with a human centrosome protein, suggesting that this key component of the C. elegans centrosome is evolutionarily conserved. 相似文献
107.
Bonnefond A Durand E Sand O De Graeve F Gallina S Busiah K Lobbens S Simon A Bellanné-Chantelot C Létourneau L Scharfmann R Delplanque J Sladek R Polak M Vaxillaire M Froguel P 《PloS one》2010,5(10):e13630
Background
Accurate molecular diagnosis of monogenic non-autoimmune neonatal diabetes mellitus (NDM) is critical for patient care, as patients carrying a mutation in KCNJ11 or ABCC8 can be treated by oral sulfonylurea drugs instead of insulin therapy. This diagnosis is currently based on Sanger sequencing of at least 42 PCR fragments from the KCNJ11, ABCC8, and INS genes. Here, we assessed the feasibility of using the next-generation whole exome sequencing (WES) for the NDM molecular diagnosis.Methodology/Principal Findings
We carried out WES for a patient presenting with permanent NDM, for whom mutations in KCNJ11, ABCC8 and INS and abnormalities in chromosome 6q24 had been previously excluded. A solution hybridization selection was performed to generate WES in 76 bp paired-end reads, by using two channels of the sequencing instrument. WES quality was assessed using a high-resolution oligonucleotide whole-genome genotyping array. From our WES with high-quality reads, we identified a novel non-synonymous mutation in ABCC8 (c.1455G>C/p.Q485H), despite a previous negative sequencing of this gene. This mutation, confirmed by Sanger sequencing, was not present in 348 controls and in the patient''s mother, father and young brother, all of whom are normoglycemic.Conclusions/Significance
WES identified a novel de novo ABCC8 mutation in a NDM patient. Compared to the current Sanger protocol, WES is a comprehensive, cost-efficient and rapid method to identify mutations in NDM patients. We suggest WES as a near future tool of choice for further molecular diagnosis of NDM cases, negative for chr6q24, KCNJ11 and INS abnormalities. 相似文献108.
Summary Preincubation at 42o, before infection at permissive temperature by phage , of an Escherichia coli dnaB mutant, provokes a significant increase in survival and mutagenesis of ultraviolet irradiated phage as well as mutagenesis of untreated phage. Similarly to UV irradiation and many chemical mutagens, the inhibition of DNA synthesis by temperature shift of this dnaB mutant induces SOS repair. This work shows that replication blockage in bacterial DNA is not only mutagenic for bacterial DNA itself (Witkin, 1975) but also for normally replicating DNA, probably due to induction of diffusible products. 相似文献
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110.