Examinando por Autor "Diacovich, Lautaro"

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    3-methylcrotonyl Coenzyme A (CoA) carboxylase complex is involved in the Xanthomonas citri subsp. citri lifestyle during citrus infection
    (Public Library of Science (PLOS), 2018-06-07) Tomassetti, Mauro; Garavaglia, Betiana Soledad; Vranych, Cecilia Verónica; Gottig, Natalia; Ottado, Jorgelina; Gramajo, Hugo Cesar; Diacovich, Lautaro
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    Complete genome sequence of the Microbacterium foliorum bacteriophage Garey24
    (American Society for Microbiology, 2024-02-05) Migueletti, Matías R.; García Rey, Julieta; Micheloni, Josefina; Lomanto, Camila; Martelli, Elisa; Sánchez, Gastón; Colombo, Julián M.; Vallecillo, Luciano M.; Lamagni, Francisco; Giusti, Tomás; Acosta, Fabrina; Villagrán, Franco; Gvozdenovich, Martín; Pricco Frakich, Abril; Pianesi, Tulio; Tulin, Gonzalo; Mascali, Florencia Carla; Petitti, Tomás D.; Torres Manno, Mariano A.; Fusari, Corina M.; Buttigliero, Laura; Giordana, María Florencia; Gramajo, Hugo Cesar; Diacovich, Lautaro; Espariz, Martín; Mussi, María Alejandra; http://orcid.org/0000-0002-3339-0100; http://orcid.org/0000-0002-4090-515X; http://orcid.org/0000-0002-4168-3624
    In this work, we report the discovery and characterization of Garey24, a bacteriophage that forms medium-size plaques with halo rings isolated from a soil sample in Funes, Argentina. Its 41,522 bp circularly permuted genome contains 63 putative protein-coding genes. Based on gene content similarity, Garey24 was assigned to subcluster EA1.
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    Expression and purification of untagged GlnK proteins from actinobacteria
    (EXCLI, 2017-06-27) Gerhardt, Edileusa C. M.; Moure, Vivian R.; Souza, Andrey W.; Pedrosa, Fabio O.; Souza, Emanuel M.; Diacovich, Lautaro; Gramajo, Hugo Cesar; Huergo, Luciano F.
    The PII protein family constitutes one of the most conserved and well distributed family of signal transduction proteins in nature. These proteins play key roles in nitrogen and carbon metabolism. PII function has been well documented in Gram-negative bacteria. However, there are very few reports describing the in vitro properties and function of PII derived from Gram-positive bacteria. Here we present the heterologous expression and efficient purification protocols for untagged PII from three Actinobacteria of medical and biotechnological interest namely: Mycobacterium tuberculosis, Rhodococcus jostii and Streptomyces coelicolor. Circular dichroism and gel filtration analysis supported that the purified proteins are correctly folded. The purification protocol described here will facilitate biochemical studies and help to uncover the biochemical functions of PII proteins in Actinobacteria.
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    KDM2B regulates choline kinase expression and neuronal differentiation of neuroblastoma cells
    (Public Library of Science (PLOS), 2019-01-10) Domizi, Pablo; Malizia, Florencia; Chazarreta-Cifre, Lorena; Diacovich, Lautaro; Banchio, Claudia
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    Light modulates important pathogenic determinants and virulence in ESKAPE pathogens Acinetobacter baumannii, Pseudomonas aeruginosa, and Staphylococcus aureus
    (American Society for Microbiology, 2021-02-08) Tuttobene, Marisel Romina; Pérez, J. F.; Pavesi, Estefanía S.; Pérez Mora, Bárbara; Biancotti, Daiana; Cribb, Pamela; Altilio, Matías; Müller, Gabriela Leticia; Gramajo, Hugo Cesar; Tamagno, G.; Ramírez, María Soledad; Diacovich, Lautaro; Mussi, María Alejandra; https://orcid.org/0000-0002-9904-7890; https://orcid.org/0000-0002-3339-0100; https://orcid.org/0000-0002-4168-3624; Rabinovich, Gabriel: provide HaCaT cells; Voyich, Jovanka: provide the hla and complemented hla mutant
    Light sensing has been extensively characterized in the human pathogen Acinetobacter baumannii at environmental temperatures. However, the influence of light on the physiology and pathogenicity of human bacterial pathogens at temperatures found in warm-blooded hosts is still poorly understand. In this work, we show that Staphylococcus aureus, Acinetobacter baumannii, and Pseudomonas aeruginosa (ESKAPE) priority pathogens, which have been recognized by the WHO and the CDC as critical, can also sense and respond to light at temperatures found in human hosts. Most interestingly, in these pathogens, light modulates important pathogenicity determinants as well as virulence in an epithelial infection model, which could have implications in human infections. In fact, we found that alpha-toxin-dependent hemolysis, motility, and growth under iron-deprived conditions are modulated by light in S. aureus. Light also regulates persistence, metabolism, and the ability to kill competitors in some of these microorganisms. Finally, light exerts a profound effect on the virulence of these pathogens in an epithelial infection model, although the response is not the same in the different species; virulence was enhanced by light in A. baumannii and S. aureus, while in A. nosocomialis and P. aeruginosa it was reduced. Neither the BlsA photoreceptor nor the type VI secretion system (T6SS) is involved in virulence modulation by light in A. baumannii. Overall, this fundamental knowledge highlights the potential use of light to control pathogen virulence, either directly or by manipulating the light regulatory switch toward the lowest virulence/persistence configuration. IMPORTANCE: Pathogenic bacteria are microorganisms capable of producing disease. Dangerous bacterial pathogens, such as Staphylococcus aureus, Pseudomonas aeruginosa, and Acinetobacter baumannii, are responsible for serious intrahospital and community infections in humans. Therapeutics is often complicated due to resistance to multiple antibiotics, rendering them ineffective. In this work, we show that these pathogens sense natural light and respond to it by modulating aspects related to their ability to cause disease; in the presence of light, some of them become more aggressive, while others show an opposite response. Overall, we provide new understanding on the behavior of these pathogens, which could contribute to the control of infections caused by them. Since the response is distributed in diverse pathogens, this notion could prove a general concept.
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    Models of classroom assessment for course-based research experiences
    (Frontiers Media, 2023-11-28) Hanauer, David I.; Zhang, Tong; Graham, Mark J.; Adams, Sandra D.; Ahumada Santos, Yesmi Patricia; Mussi, María Alejandra; Diacovich, Lautaro
    Course-based research pedagogy involves positioning students as contributors to authentic research projects as part of an engaging educational experience that promotes their learning and persistence in science. To develop a model for assessing and grading students engaged in this type of learning experience, the assessment aims and practices of a community of experienced course-based research instructors were collected and analyzed. This approach defines four aims of course-based research assessment—(1) Assessing Laboratory Work and Scientific Thinking; (2) Evaluating Mastery of Concepts, Quantitative Thinking and Skills; (3) Appraising Forms of Scientific Communication; and (4) Metacognition of Learning—along with a set of practices for each aim. These aims and practices of assessment were then integrated with previously developed models of coursebased research instruction to reveal an assessment program in which instructors provide extensive feedback to support productive student engagement in research while grading those aspects of research that are necessary for the student to succeed. Assessment conducted in this way delicately balances the need to facilitate students’ ongoing research with the requirement of a final grade without undercutting the important aims of a CRE education.
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    Mycobacterium tuberculosis FasR senses long fatty acyl-CoA through a tunnel and a hydrophobic transmission spine
    (Springer Nature, 2020-07-24) Lara, María Julia; Diacovich, Lautaro; Trajtenberg, Felipe; Larrieux, Nicole; Malchiodi, Emilio L.; Fernández, Marisa M.; Gago, Gabriela; Gramajo, Hugo Cesar; Buschiazzo, Alejandro; https://orcid.org/0000-0002-3339-0100; https://orcid.org/0000-0003-0427-5549; https://orcid.org/0000-0001-7501-3330; https://orcid.org/0000-0001-7668-0119; https://orcid.org/0000-0002-2509-6526
    Mycobacterium tuberculosis is a pathogen with a unique cell envelope including very long fatty acids, implicated in bacterial resistance and host immune modulation. FasR is a TetR-like transcriptional activator that plays a central role in sensing mycobacterial long-chain fatty acids and regulating lipid biosynthesis. Here we disclose crystal structures of M. tuberculosis FasR in complex with acyl effector ligands and with DNA, uncovering its molecular sensory and switching mechanisms. A long tunnel traverses the entire effector-binding domain, enabling long fatty acyl effectors to bind. Only when the tunnel is entirely occupied, the protein dimer adopts a rigid configuration with its DNA-binding domains in an open state, leading to DNA dissociation. The protein-folding hydrophobic core connects the two domains, and is completed into a continuous spine when the effector binds. Such a transmission spine is conserved in a large number of TetR-like regulators, offering insight into effector-triggered allosteric functional control.
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    Pleiotropic effect of AccD5 and AccE5 depletion in acyl-coenzyme a carboxylase activity and in lipid biosynthesis in mycobacteria
    (Public Library of Science, 2014-06-20) Bazet Lyonnet, Bernardo; Diacovich, Lautaro; Cabruja, Matías Ezequiel; Bardou, Fabienne; Quémard, Annaïk; Gago, Gabriela; Gramajo, Hugo Cesar
    Mycobacteria contain a large variety of fatty acids which are used for the biosynthesis of several complex cell wall lipids that have been implicated in the ability of the organism to resist host defenses. The building blocks for the biosynthesis of all these lipids are provided by a fairly complex set of acyl-CoA carboxylases (ACCases) whose subunit composition and roles within these organisms have not yet been clearly established. Previous biochemical and structural studies provided strong evidences that ACCase 5 from Mycobacterium tuberculosis is formed by the AccA3, AccD5 and AccE5 subunits and that this enzyme complex carboxylates acetyl-CoA and propionyl-CoA with a clear substrate preference for the latest. In this work we used a genetic approach to unambiguously demonstrate that the products of both accD5 and accE5 genes are essential for the viability of Mycobacterium smegmatis. By obtaining a conditional mutant on the accD5-accE5 operon, we also demonstrated that the main physiological role of this enzyme complex was to provide the substrates for fatty acid and mycolic acid biosynthesis. Furthermore, enzymatic and biochemical analysis of the conditional mutant provided strong evidences supporting the notion that AccD5 and/or AccE5 have an additional role in the carboxylation of long chain acylCoA prior to mycolic acid condensation. These studies represent a significant step towards a better understanding of the roles of ACCases in mycobacteria and confirm ACCase 5 as an interesting target for the development of new antimycobacterial drugs.
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    Polar protein Wag31 both activates and inhibits cell wall metabolism at the poles and septum
    (Frontiers Media, 2023-01-12) Habibi Arejan, Neda; Ensinck, Delfina; Diacovich, Lautaro; Patel, Parthvi Bharatkumar; Quintanilla, Samantha Y.; Emami Saleh, Arash; Gramajo, Hugo Cesar; Boutte, Cara C.