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Vijay Pancholi - One of the best experts on this subject based on the ideXlab platform.

  • modulation of Cell Wall Structure and antimicrobial susceptibility by a staphylococcus aureus eukaryote like serine threonine kinase and phosphatase
    Infection and Immunity, 2009
    Co-Authors: Amanda Michelle Beltramini, Chitrangada Das Mukhopadhyay, Vijay Pancholi
    Abstract:

    It is well established that prokaryotes and eukaryotes alike utilize phosphotransfer to regulate Cellular functions. One method by which this occurs is via eukaryote-like serine/threonine kinase (ESTK)- and phosphatase (ESTP)-regulated pathways. The role of these enzymes in Staphylococcus aureus has not yet been examined. This resilient organism is a common cause of hospital-acquired and community-associated infections, infecting immunocompromised and immunocompetent hosts alike. In this study, we have characterized a major functional ESTK (STK) and ESTP (STP) in S. aureus and found them to be critical modulators of Cell Wall Structure and susceptibility to Cell Wall-acting β-lactam antibiotics. By utilizing gene knockout strategies, we created S. aureus N315 mutants lacking STP and/or STK. The strain lacking both STP and STK displayed notable Cell division defects, including multiple and incomplete septa, bulging, and irregular Cell size, as observed by transmission electron microscopy. Mutants lacking STP alone displayed thickened Cell Walls and increased resistance to the peptidoglycan-targeting glycylglycine endopeptidase lysostaphin, compared to the wild type. Additionally, mutant strains lacking STK or both STK and STP displayed increased sensitivity to Cell Wall-acting cephalosporin and carbapenem antibiotics. Together, these results indicate that S. aureus STK- and STP-mediated reversible phosphorylation reactions play a critical role in proper Cell Wall architecture, and thus the modulation of antimicrobial resistance, in S. aureus.

  • Modulation of Cell Wall Structure and Antimicrobial Susceptibility by a Staphylococcus aureus Eukaryote-Like Serine/Threonine Kinase and Phosphatase
    Infection and immunity, 2009
    Co-Authors: Amanda Michelle Beltramini, Chitrangada Das Mukhopadhyay, Vijay Pancholi
    Abstract:

    It is well established that prokaryotes and eukaryotes alike utilize phosphotransfer to regulate Cellular functions. One method by which this occurs is via eukaryote-like serine/threonine kinase (ESTK)- and phosphatase (ESTP)-regulated pathways. The role of these enzymes in Staphylococcus aureus has not yet been examined. This resilient organism is a common cause of hospital-acquired and community-associated infections, infecting immunocompromised and immunocompetent hosts alike. In this study, we have characterized a major functional ESTK (STK) and ESTP (STP) in S. aureus and found them to be critical modulators of Cell Wall Structure and susceptibility to Cell Wall-acting β-lactam antibiotics. By utilizing gene knockout strategies, we created S. aureus N315 mutants lacking STP and/or STK. The strain lacking both STP and STK displayed notable Cell division defects, including multiple and incomplete septa, bulging, and irregular Cell size, as observed by transmission electron microscopy. Mutants lacking STP alone displayed thickened Cell Walls and increased resistance to the peptidoglycan-targeting glycylglycine endopeptidase lysostaphin, compared to the wild type. Additionally, mutant strains lacking STK or both STK and STP displayed increased sensitivity to Cell Wall-acting cephalosporin and carbapenem antibiotics. Together, these results indicate that S. aureus STK- and STP-mediated reversible phosphorylation reactions play a critical role in proper Cell Wall architecture, and thus the modulation of antimicrobial resistance, in S. aureus.

Amanda Michelle Beltramini - One of the best experts on this subject based on the ideXlab platform.

  • modulation of Cell Wall Structure and antimicrobial susceptibility by a staphylococcus aureus eukaryote like serine threonine kinase and phosphatase
    Infection and Immunity, 2009
    Co-Authors: Amanda Michelle Beltramini, Chitrangada Das Mukhopadhyay, Vijay Pancholi
    Abstract:

    It is well established that prokaryotes and eukaryotes alike utilize phosphotransfer to regulate Cellular functions. One method by which this occurs is via eukaryote-like serine/threonine kinase (ESTK)- and phosphatase (ESTP)-regulated pathways. The role of these enzymes in Staphylococcus aureus has not yet been examined. This resilient organism is a common cause of hospital-acquired and community-associated infections, infecting immunocompromised and immunocompetent hosts alike. In this study, we have characterized a major functional ESTK (STK) and ESTP (STP) in S. aureus and found them to be critical modulators of Cell Wall Structure and susceptibility to Cell Wall-acting β-lactam antibiotics. By utilizing gene knockout strategies, we created S. aureus N315 mutants lacking STP and/or STK. The strain lacking both STP and STK displayed notable Cell division defects, including multiple and incomplete septa, bulging, and irregular Cell size, as observed by transmission electron microscopy. Mutants lacking STP alone displayed thickened Cell Walls and increased resistance to the peptidoglycan-targeting glycylglycine endopeptidase lysostaphin, compared to the wild type. Additionally, mutant strains lacking STK or both STK and STP displayed increased sensitivity to Cell Wall-acting cephalosporin and carbapenem antibiotics. Together, these results indicate that S. aureus STK- and STP-mediated reversible phosphorylation reactions play a critical role in proper Cell Wall architecture, and thus the modulation of antimicrobial resistance, in S. aureus.

  • Modulation of Cell Wall Structure and Antimicrobial Susceptibility by a Staphylococcus aureus Eukaryote-Like Serine/Threonine Kinase and Phosphatase
    Infection and immunity, 2009
    Co-Authors: Amanda Michelle Beltramini, Chitrangada Das Mukhopadhyay, Vijay Pancholi
    Abstract:

    It is well established that prokaryotes and eukaryotes alike utilize phosphotransfer to regulate Cellular functions. One method by which this occurs is via eukaryote-like serine/threonine kinase (ESTK)- and phosphatase (ESTP)-regulated pathways. The role of these enzymes in Staphylococcus aureus has not yet been examined. This resilient organism is a common cause of hospital-acquired and community-associated infections, infecting immunocompromised and immunocompetent hosts alike. In this study, we have characterized a major functional ESTK (STK) and ESTP (STP) in S. aureus and found them to be critical modulators of Cell Wall Structure and susceptibility to Cell Wall-acting β-lactam antibiotics. By utilizing gene knockout strategies, we created S. aureus N315 mutants lacking STP and/or STK. The strain lacking both STP and STK displayed notable Cell division defects, including multiple and incomplete septa, bulging, and irregular Cell size, as observed by transmission electron microscopy. Mutants lacking STP alone displayed thickened Cell Walls and increased resistance to the peptidoglycan-targeting glycylglycine endopeptidase lysostaphin, compared to the wild type. Additionally, mutant strains lacking STK or both STK and STP displayed increased sensitivity to Cell Wall-acting cephalosporin and carbapenem antibiotics. Together, these results indicate that S. aureus STK- and STP-mediated reversible phosphorylation reactions play a critical role in proper Cell Wall architecture, and thus the modulation of antimicrobial resistance, in S. aureus.

Chitrangada Das Mukhopadhyay - One of the best experts on this subject based on the ideXlab platform.

  • modulation of Cell Wall Structure and antimicrobial susceptibility by a staphylococcus aureus eukaryote like serine threonine kinase and phosphatase
    Infection and Immunity, 2009
    Co-Authors: Amanda Michelle Beltramini, Chitrangada Das Mukhopadhyay, Vijay Pancholi
    Abstract:

    It is well established that prokaryotes and eukaryotes alike utilize phosphotransfer to regulate Cellular functions. One method by which this occurs is via eukaryote-like serine/threonine kinase (ESTK)- and phosphatase (ESTP)-regulated pathways. The role of these enzymes in Staphylococcus aureus has not yet been examined. This resilient organism is a common cause of hospital-acquired and community-associated infections, infecting immunocompromised and immunocompetent hosts alike. In this study, we have characterized a major functional ESTK (STK) and ESTP (STP) in S. aureus and found them to be critical modulators of Cell Wall Structure and susceptibility to Cell Wall-acting β-lactam antibiotics. By utilizing gene knockout strategies, we created S. aureus N315 mutants lacking STP and/or STK. The strain lacking both STP and STK displayed notable Cell division defects, including multiple and incomplete septa, bulging, and irregular Cell size, as observed by transmission electron microscopy. Mutants lacking STP alone displayed thickened Cell Walls and increased resistance to the peptidoglycan-targeting glycylglycine endopeptidase lysostaphin, compared to the wild type. Additionally, mutant strains lacking STK or both STK and STP displayed increased sensitivity to Cell Wall-acting cephalosporin and carbapenem antibiotics. Together, these results indicate that S. aureus STK- and STP-mediated reversible phosphorylation reactions play a critical role in proper Cell Wall architecture, and thus the modulation of antimicrobial resistance, in S. aureus.

  • Modulation of Cell Wall Structure and Antimicrobial Susceptibility by a Staphylococcus aureus Eukaryote-Like Serine/Threonine Kinase and Phosphatase
    Infection and immunity, 2009
    Co-Authors: Amanda Michelle Beltramini, Chitrangada Das Mukhopadhyay, Vijay Pancholi
    Abstract:

    It is well established that prokaryotes and eukaryotes alike utilize phosphotransfer to regulate Cellular functions. One method by which this occurs is via eukaryote-like serine/threonine kinase (ESTK)- and phosphatase (ESTP)-regulated pathways. The role of these enzymes in Staphylococcus aureus has not yet been examined. This resilient organism is a common cause of hospital-acquired and community-associated infections, infecting immunocompromised and immunocompetent hosts alike. In this study, we have characterized a major functional ESTK (STK) and ESTP (STP) in S. aureus and found them to be critical modulators of Cell Wall Structure and susceptibility to Cell Wall-acting β-lactam antibiotics. By utilizing gene knockout strategies, we created S. aureus N315 mutants lacking STP and/or STK. The strain lacking both STP and STK displayed notable Cell division defects, including multiple and incomplete septa, bulging, and irregular Cell size, as observed by transmission electron microscopy. Mutants lacking STP alone displayed thickened Cell Walls and increased resistance to the peptidoglycan-targeting glycylglycine endopeptidase lysostaphin, compared to the wild type. Additionally, mutant strains lacking STK or both STK and STP displayed increased sensitivity to Cell Wall-acting cephalosporin and carbapenem antibiotics. Together, these results indicate that S. aureus STK- and STP-mediated reversible phosphorylation reactions play a critical role in proper Cell Wall architecture, and thus the modulation of antimicrobial resistance, in S. aureus.

Joan Rigau - One of the best experts on this subject based on the ideXlab platform.

  • The maize ZmMYB42 represses the phenylpropanoid pathway and affects the Cell Wall Structure, composition and degradability in Arabidopsis thaliana
    Plant Molecular Biology, 2009
    Co-Authors: Fathi-mohamed Sonbol, Silvia Fornalé, Montserrat Capellades, Antonio Encina, Sonia Touriño, Josep-lluís Torres, Pere Rovira, Katia Ruel, Pere Puigdomènech, Joan Rigau
    Abstract:

    The involvement of the maize Zm MYB42 R2R3-MYB factor in the phenylpropanoid pathway and Cell Wall Structure and composition was investigated by overexpression in Arabidopsis thaliana . Zm MYB42 down-regulates several genes of the lignin pathway and this effect reduces the lignin content in all lignified tissues. In addition, Zm MYB42 plants generate a lignin polymer with a decreased S to G ratio through the enrichment in H and G subunits and depletion in S subunits. This transcription factor also regulates other genes involved in the synthesis of sinapate esters and flavonoids. Furthermore, Zm MYB42 affects the Cell Wall Structure and degradability, and its polysaccharide composition. Together, these results suggest that Zm MYB42 may be part of the regulatory network controlling the phenylpropanoid biosynthetic pathway.

  • ZmXTH1, a new xyloglucan endotransglucosylase/hydrolase in maize, affects Cell Wall Structure and composition in Arabidopsis thaliana
    Journal of experimental botany, 2008
    Co-Authors: Valeria Genovesi, Fathi-mohamed Sonbol, Silvia Fornalé, Antonio Encina, Katia Ruel, Pere Puigdomènech, Stephen C. Fry, Pau Ferrer, Josep Bosch, Joan Rigau
    Abstract:

    Xyloglucan endotransglucosylase/hydrolases (XTHs; EC 2.4.1.207 and/or EC 3.2.1.151) are enzymes involved in the modification of Cell Wall Structure by cleaving and, often, also re-joining xyloglucan molecules in primary plant Cell Walls. Using a pool of antibodies raised against an enriched Cell Wall protein fraction, a new XTH cDNA in maize, ZmXTH1, has been isolated from a cDNA expression library obtained from the elongation zone of the maize root. The predicted protein has a putative N-terminal signal peptide and possesses the typical domains of this enzyme family, such as a catalytic domain that is homologous to that of Bacillus macerans b-glucanase, a putative Nglycosylation motif, and four cysteine residues in the central and C terminal regions of the ZmXTH1 protein. Phylogenetic analysis of ZmXTH1 reveals that it belongs to subgroup 4, so far only reported from Poaceae monocot species. ZmXTH1 has been expressed in Pichia pastoris (a methylotrophic yeast) and the recombinant enzyme showed xyloglucan endotransglucosylase but not xyloglucan endohydrolase activity, representing the first enzyme belonging to subgroup 4 characterized in maize so far. Expression data indicate that ZmXTH1 is expressed in elongating tissues, modulated by culture conditions, and induced by gibberellins. Transient expression assays in onion Cells reveal that ZmXTH1 is directed to the Cell Wall, although weakly bound. Finally, Arabidopsis thaliana plants expressing ZmXTH1 show slightly increased xyloglucan endohydrolase activity and alterations in the Cell Wall Structure and composition.

Stanley Brul - One of the best experts on this subject based on the ideXlab platform.

  • dynamics of Cell Wall Structure in saccharomyces cerevisiae
    Fems Microbiology Reviews, 2002
    Co-Authors: Frans M. Klis, Klaas Hellingwerf, Stanley Brul
    Abstract:

    The Cell Wall of Saccharomyces cerevisiae is an elastic Structure that provides osmotic and physical protection and determines the shape of the Cell. The inner layer of the Wall is largely responsible for the mechanical strength of the Wall and also provides the attachment sites for the proteins that form the outer layer of the Wall. Here we find among others the sexual agglutinins and the flocculins. The outer protein layer also limits the permeability of the Cell Wall, thus shielding the plasma membrane from attack by foreign enzymes and membrane-perturbing compounds. The main features of the molecular organization of the yeast Cell Wall are now known. Importantly, the molecular composition and organization of the Cell Wall may vary considerably. For example, the incorporation of many Cell Wall proteins is temporally and spatially controlled and depends strongly on environmental conditions. Similarly, the formation of specific Cell Wall protein–polysaccharide complexes is strongly affected by external conditions. This points to a tight regulation of Cell Wall construction. Indeed, all five mitogen-activated protein kinase pathways in bakers’ yeast affect the Cell Wall, and additional Cell Wall-related signaling routes have been identified. Finally, some potential targets for new antifungal compounds related to Cell Wall construction are discussed.