(FBIOyF) Departamento de Química Orgánica

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https://rephip.unr.edu.ar/handle/2133/2557

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Examinando (FBIOyF) Departamento de Química Orgánica por Autor "Abriata, Luciano Andrés"

Mostrando 1 - 3 de 3
  • Miniatura
    ÍtemAcceso Abierto
    A coiled coil switch mediates cold sensing by the thermosensory protein DesK
    (Wiley, 2015-10-08) Saita, Emilio Adolfo; Abriata, Luciano Andrés; Tsai, Yi-Ting; Trajtenberg, Felipe; Lemmin, Thomas; Buschiazzo, Alejandro; Dal Peraro, Matteo; De Mendoza, Diego; Albanesi, Daniela
    The thermosensor histidine kinase DesK from Bacillus subtilis senses changes in membrane fluidity initiating an adaptive response. Structural changes in DesK have been implicated in transmembrane signaling, but direct evidence is still lacking. On the basis of structure-guided mutagenesis, we now propose a mechanism of DesK-mediated signal sensing and transduction. The data indicate that stabilization/destabilization of a 2-helix coiled coil, which connects the transmembrane sensory domain of DesK to its cytosolic catalytic region, is crucial to control its signaling state. Computational modeling and simulations reveal couplings between protein, water and membrane mechanics. We propose that membrane thickening is the main driving force for signal sensing and that it acts by inducing helix stretching and rotation prompting an asymmetric kinase-competent state. Overall, the known structural changes of the sensor kinase, as well as further dynamic rearrangements that we now predict, consistently link structure determinants to activity modulation.
  • Miniatura
    ÍtemAcceso Abierto
    MoleculARweb: a web site for chemistry and structural biology education through interactive augmented reality out of the box in bommodity devices
    (American Chemical Society, 2021-07-13) Cortés Rodríguez, Fabio; Frattini, Gianfranco; Krapp, Lucien F.; Martínez-Hung, Hassan; Moreno, Diego M.; Roldán, Mariana; Salomón, Jorge; Stemkoski, Lee; Traeger, Sylvain; Del Peraro, Matteo; Abriata, Luciano Andrés
  • Miniatura
    ÍtemAcceso Abierto
    XacFhaB adhesin, an important Xanthomonas citri ssp. citri virulence factor, is recognized as a pathogen-associated molecular pattern
    (BSPP and Wiley, 2016-11-15) Garavaglia, Betiana Soledad; Zimaro, Tamara; Abriata, Luciano Andrés; Ottado, Jorgelina; Gottig, Natalia
    Adhesion to host tissue is one of the key steps of the bacterial pathogenic process. Xanthomonas citri ssp. citri possesses a non-fimbrial adhesin protein, XacFhaB, required for bacterial attachment, which we have previously demonstrated to be an important virulence factor for the development of citrus canker. XacFhaB is a 4753-residue-long protein with a predicted β-helical fold structure, involved in bacterial aggregation, biofilm formation and adhesion to the host. In this work, to further characterize this protein and considering its large size, XacFhaB was dissected into three regions based on bioinformatic and structural analyses for functional studies. First, the capacity of these protein regions to aggregate bacterial cells was analysed. Two of these regions were able to form bacterial aggregates, with the most amino-terminal region being dispensable for this activity. Moreover, XacFhaB shows features resembling pathogen-associated molecular patterns (PAMPs), which are recognized by plants. As PAMPs activate plant basal immune responses, the role of the three XacFhaB regions as elicitors of these responses was investigated. All adhesin regions were able to induce basal immune responses in host and non-host plants, with a stronger activation by the carboxyl-terminal region. Furthermore, pre-infiltration of citrus leaves with XacFhaB regions impaired X. citri ssp. citri growth, confirming the induction of defence responses and restraint of citrus canker. This work reveals that adhesins from plant pathogens trigger plant defence responses, opening up new pathways for the development of protective strategies for disease control.