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Diverse Processes (diverse + process)
Selected AbstractsRegulation of virulence and antibiotic resistance by two-component regulatory systems in Pseudomonas aeruginosaFEMS MICROBIOLOGY REVIEWS, Issue 2 2009W. James Gooderham Abstract The Gram-negative opportunistic pathogen Pseudomonas aeruginosa ubiquitously inhabits soil and water habitats and also causes serious, often antibiotic resistant, infections in immunocompromised patients (e.g. cystic fibrosis). This versatility is mediated in part by a large repertoire of two-component regulatory systems that appear instrumental in the regulation of both virulence processes and resistance to antimicrobials. Major two-component regulatory system proteins demonstrated to regulate these diverse processes include PhoP,PhoQ, GacA,GacS, RetS, LadS, and AlgR, among others. Here, we summarize the current body of knowledge of these and other two-component systems that provides insight into the complex regulation of virulence and resistance in P. aeruginosa. [source] Molecular cloning of two prophenoloxidase genes from the mosquito Aedes aegyptiINSECT MOLECULAR BIOLOGY, Issue 1 2001A. S. Taft Abstract The biosynthesis of melanotic materials is an important process in the life of a mosquito. Melanin production is critical for many diverse processes such as egg chorion tanning, cuticular sclerotization, and melanotic encapsulation of metazoan parasites. Prophenoloxidase plays a critical role in this biochemical cascade. Two cDNAs, one full length and one partial clone, and two genomic clones encoding prophenoloxidase (pro-PO) were isolated from the yellow fever mosquito, Aedes aegypti. The full-length cDNA, pAaProPO1, is 2286 bp long with a 2055 bp open reading frame encoding a 685 amino acid protein that shares 89% identity with Armigeres subalbatus pro - PO. It contains two putative copper binding domains (amino acids 197,243 and 346,423) that are homologous to other insect pro-POs. AaProPO1 messenger RNA (mRNA) was detected by reverse transcription polymerase chain reaction (RT-PCR) only from third-stage larvae and not in adult mosquitoes after blood feeding, during the melanotic encapsulation of Dirofilaria immitis microfilariae or following exposure to bacteria. A 750 bp fragment of the second cDNA (pAaProPO2) was cloned using RT-PCR from mRNA obtained from 14-day postovipostional eggs. AaProPO2 mRNA was not found in any other life stages, and may be in low abundance or transiently expressed. AaProPO2 and AaProPO1 each contain three introns that are 60, 68 and 58 bp and 61, 69 and 59 bp long, respectively, and the intron sequences of these two genes are not similar. [source] Multigenerational analysis of spatial structure in the terrestrial, food-deceptive orchid Orchis masculaJOURNAL OF ECOLOGY, Issue 2 2009Hans Jacquemyn Summary 1In long-lived, terrestrial orchids, strong aggregation of adults and recruits within populations and pronounced spatial association between recruits and adults can be expected when seed dispersal is limited, probabilities of seed germination decrease with increasing distance from mother plants and/or not all mother plants contribute to future generations. When individuals are distributed evenly across life-history stages, these processes can also be expected to result in a significant fine-scale spatial genetic structure in recruits that will persist into the adult-stage class. 2We combined detailed spatial genetic and point pattern analyses across different generations with parentage analyses to elucidate the role of the diverse processes that might determine spatial structure in Orchis mascula. 3Analyses of spatial point patterns showed a significant association between adults and recruits and similar clustering patterns for both. Weak, but highly significant spatial genetic structure was observed in adults and recruits, but no significant differences were observed across life stages, indicating that the spatial genetic structure present in recruits persists into the adult stage. 4Parentage analyses highlighted relatively short seed dispersal distances (median offspring-recruitment distance: 1.55 and 1.70 m) and differential contribution of mother plants to future generations. 5Persistence of fine-scale spatial genetic structure from seedlings into the adult stage class is consistent with the life history of O. mascula, whereas relatively large dispersal distances of both pollen and seeds compared to the fine-scale clustering of adults and seedlings suggest overlapping seed shadows and mixing of genotypes within populations as the major factors explaining the observed weak spatial genetic structure. 6Nonetheless, comparison of the spatial association between recruits and adults with the genetic analysis of offspring-parent distances suggests that the tight clustering of recruits around adults was probably caused by decreasing probabilities of seed germination with increasing distance from mother plants. 7Synthesis. This study shows that the approach presented here, which combines spatial genetic and spatial pattern analyses with parentage analyses, may be broadly applied to other plant species to elucidate the processes that determine spatial structure within their populations. [source] Platelet functions beyond hemostasisJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 11 2009S. S. SMYTH Summary., Although their central role is in the prevention of bleeding, platelets probably contribute to diverse processes that extend beyond hemostasis and thrombosis. For example, platelets can recruit leukocytes and progenitor cells to sites of vascular injury and inflammation; they release proinflammatory and anti-inflammatory and angiogenic factors and microparticles into the circulation; and they spur thrombin generation. Data from animal models suggest that these functions may contribute to atherosclerosis, sepsis, hepatitis, vascular restenosis, acute lung injury, and transplant rejection. This article represents an integrated summary of presentations given at the Fourth Annual Platelet Colloquium in January 2009. The process of and factors mediating platelet,platelet and platelet,leukocyte interactions in inflammatory and immune responses are discussed, with the roles of P-selectin, chemokines and Src family kinases being highlighted. Also discussed are specific disorders characterized by local or systemic platelet activation, including coronary artery restenosis after percutaneous intervention, alloantibody-mediated transplant rejection, wound healing, and heparin-induced thrombocytopenia. [source] Differential Regulation of Five Pht1 Phosphate Transporters from Maize (Zea mays L.)PLANT BIOLOGY, Issue 2 2006R. Nagy Abstract: Maize is one of the most important crops in the developing world, where adverse soil conditions and low fertilizer input are the two main constraints for stable food supply. Understanding the molecular and biochemical mechanisms involved in nutrient uptake is expected to support the development of future breeding strategies aimed at improving maize productivity on infertile soils. Phosphorus is the least mobile macronutrient in the soils and it is often limiting plant growth. In this work, five genes encoding Pht1 phosphate transporters which contribute to phosphate uptake and allocation in maize were identified. In phosphate-starved plants, transcripts of most of the five transporters were present in roots and leaves. Independent of the phosphate supply, expression of two genes was predominant in pollen or in roots colonized by symbiotic mycorrhizal fungi, respectively. Interestingly, high transcript levels of the mycorrhiza-inducible gene were also detectable in leaves of phosphate-starved plants. Thus, differential expression of Pht1 phosphate transporters in maize suggests involvement of the encoded proteins in diverse processes, including phosphate uptake from soil and transport at the symbiotic interface in mycorrhizas, phosphate (re)translocation in the shoot, and phosphate uptake during pollen tube growth. [source] Protein-induced changes during the maturation process of human dendritic cells: A 2-D DIGE approachPROTEOMICS - CLINICAL APPLICATIONS, Issue 9 2008Gabriela Bomfim Ferreira Abstract Dendritic cells (DCs) are unique antigen presenting cells, which upon maturation change from a specialized antigen-capturing cell towards a professional antigen presenting cells. In this study, a 2-D DIGE analysis of immature and mature DCs was performed, to identify proteins changing in expression upon maturation. The protein expression profile of immature and mature DCs, derived from CD14+ peripheral blood monocytes was investigated using two pH ranges (pH,4,7 and 6,9) (n,=,4). Ninety one differentially expressed spots (p<0.01) were detected, from which we identified 74 spots (81.32%) corresponding to 41 different proteins. The proteins identified play a role in diverse processes, such as antigen processing/presentation, vesicle transport and cytoskeleton remodeling. In addition, a protein interaction network contained 29 (out of 41) proteins, suggesting that, although they functionally originate from distinct classes, these proteins are acting as a protein-interactome. In conclusion, the proteins shown here to be altered in expression upon maturation are in line with the morphological and functional changes observed during the maturation process, providing a better understanding of the processes involved. This will open new avenues for investigating treatment regimens for immune-associated disorders. [source] Crystal optimization and preliminary diffraction data analysis of the Smad1 MH1 domain bound to a palindromic SBE DNA elementACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 11 2009Nithya Baburajendran The bone morphogenetic protein (BMP) signalling pathway regulates diverse processes such as cell differentiation, anterior/posterior axis specification, cell growth and the formation of extra-embryonic tissues. The transcription factor Smad1 relays the BMP signal from the cytoplasm to the nucleus, where it binds short DNA-sequence motifs and regulates gene expression. However, how Smad1 selectively targets particular genomic regions is poorly understood. In order to understand the physical basis of the specific interaction of Smad1 with DNA and to contrast it with the highly homologous but functionally distinct Smad3 protein, the DNA-binding Mad-homology 1 (MH1) domain of Smad1 was cocrystallized with a 17-mer palindromic Smad-binding element (SBE). The extensive optimizations of the length, binding-site spacing and terminal sequences of the DNA element in combination with the other crystallization parameters necessary for obtaining diffraction-quality crystals are described here. A 2.7,Å resolution native data set was collected at the National Synchrotron Radiation Research Centre, Taiwan, from crystals grown in a solution containing 0.2,M ammonium tartrate dibasic, 20% PEG 3350, 3% 2-propanol and 10% glycerol. The data set was indexed and merged in space group P222, with unit-cell parameters a = 73.94, b = 77.49, c = 83.78,Å, , = , = , = 90°. The solvent content in the unit cell is consistent with the presence of two Smad1 MH1 molecules bound to the duplex DNA in the asymmetric unit. [source] Technoreview: Molecular imaging of host,pathogen interactions in intact small animalsCELLULAR MICROBIOLOGY, Issue 4 2004David Piwnica-Worms Summary Characterization and non-invasive measurement of host,pathogen interactions in living cells, animal models and humans at the cellular and molecular levels is now possible using remote imaging detectors. Positron emission tomography scanners, highly sensitive cooled charge-coupled device cameras for bioluminescence and fluorescence imaging as well as high-magnetic-field magnetic resonance imaging scanners can be used to study such diverse processes as pathogen tropism, pathogen life cycle, signal transduction, host response, cell trafficking and gene transfer. In many cases, images from more than one modality can be fused, allowing structure,function and multifunction relationships to be studied on a tissue-restricted or regional basis. These new instruments, when used in conjunction with targeted contrast agents, reporter substrates and radiopharmaceuticals, enable ,molecular imaging' with enormous potential for elucidating host,pathogen interactions in intact animal models. [source] Specific Labeling of Peptidoglycan Precursors as a Tool for Bacterial Cell Wall StudiesCHEMBIOCHEM, Issue 4 2009Vincent van Dam Abstract Wall chart: The predominant component of the bacterial cell wall, peptidoglycan, consists of long alternating stretches of aminosugar subunits interlinked in a large three-dimensional network and is formed from precursors through several cytosolic and membrane-bound steps. The high tolerance of the cell wall synthesis machinery allows for the use of labeled precursor derivatives to study diverse aspects of bacterial cell wall synthesis and interaction with antibiotics. Because of its importance for bacterial cell survival, the bacterial cell wall is an attractive target for new antibiotics in a time of great demand for new antibiotic compounds. Therefore, more knowledge about the diverse processes related to bacterial cell wall synthesis is needed. The cell wall is located on the exterior of the cell and consists mainly of peptidoglycan, a large macromolecule built up from a three-dimensional network of aminosugar strands interlinked with peptide bridges. The subunits of peptidoglycan are synthesized inside the cell before they are transported to the exterior in order to be incorporated into the growing peptidoglycan. The high flexibility of the cell wall synthesis machinery towards unnatural derivatives of these subunits enables research on the bacterial cell wall using labeled compounds. This review highlights the high potential of labeled cell wall precursors in various areas of cell wall research. Labeled precursors can be used in investigating direct cell wall,antibiotic interactions and in cell wall synthesis and localization studies. Moreover, these compounds can provide a powerful tool in the elucidation of the cell wall proteome, the "wallosome," and thus, might provide new targets for antibiotics. [source] | |||||||||||||