40 research outputs found

    Aty guasu América Latina ha Interculturalidad

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    Anais do I Congresso Internacional América Latina e Interculturalidade - América Latina e Caribe: cenários linguístico-culturais contemporâneos, que aconteceu em Foz do Iguaçu, entre os dias 07, 08 e 09 de novembro de 2013 na Universidade Federal de Integração Latino-Americana e que agora se publicam no site do Programa Interdisciplinar de Estudos Latino-Americanos (Pós IELA).É com satisfação que apresentamos os anais do I Congresso Internacional América Latina e Interculturalidade - América Latina e Caribe: cenários linguístico-culturais contemporâneos, que aconteceu em Foz do Iguaçu, entre os dias 07 e 9 de novembro na Universidade Federal de Integração Latino-Americana e que agora se publicam no site do Programa Interdisciplinar de Estudos Latino-Americanos (Pós IELA). Vale lembrar que o evento, sob a Coordenação da Profa. Dra. Maria Eta Vieira, tentou estabelecer discussões interdisciplinares, congregando diferentes áreas do Instituto Latino- Americano de Artes, Cultura e História (ILAACH). Decorrente do I Seminário de Bilinguismo e Educação Bilíngue, realizado em julho de 2011 e da I Semana de Mediação Cultural, celebrada em novembro de 2012, ambos os eventos de abrangência local ocorridos na Universidade Federal da Integração Latino-Americana, surgiram de uma necessidade interna de reflexão sobre os processos de constituição do ensino de línguas e de um curso de Letras (Letras, Artes e Mediação Cultural) inovador e contemporâneo no contexto particular da UNILA.Universidade Federal da Integração Latino-Americana - UNIL

    eSPC: An online data-analysis platform for molecular biophysics

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    All biological processes rely on the formation of protein–ligand, protein–peptide and protein–protein complexes. Studying the affinity, kinetics and thermodynamics of binding between these pairs is critical for understanding basic cellular mechanisms. Many different technologies have been designed for probing interactions between biomolecules, each based on measuring different signals (fluorescence, heat, thermophoresis, scattering and interference, among others). Evaluation of the data from binding experiments and their fitting is an essential step towards the quantification of binding affinities. Here, user-friendly online tools to analyze biophysical data from steady-state fluorescence spectroscopy, microscale thermophoresis and differential scanning fluorimetry experiments are presented. The modules of the data-analysis platform (https://spc.embl-hamburg.de/) contain classical thermodynamic models and clear user guidelines for the determination of equilibrium dissociation constants (Kd) and thermal unfolding parameters such as melting temperatures (Tm).Fil: Burastero, Osvaldo. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Niebling, Stephan. Centre For Structural Systems Biology; Alemania. European Molecular Biology Laboratory Hamburg; AlemaniaFil: Defelipe, Lucas Alfredo. Centre For Structural Systems Biology; Alemania. European Molecular Biology Laboratory Hamburg; Alemania. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Günther, Christian. Centre For Structural Systems Biology; Alemania. European Molecular Biology Laboratory Hamburg; AlemaniaFil: Struve, Angelica. Centre For Structural Systems Biology; Alemania. European Molecular Biology Laboratory Hamburg; AlemaniaFil: Garcia Alai, Maria M.. Centre For Structural Systems Biology; Alemania. European Molecular Biology Laboratory Hamburg; Alemani

    Chaperone holdase activity of human papillomavirus E7 oncoprotein

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    E7 oncoprotein is the major transforming activity in human papillomavirus and shares sequence and functional properties with adenovirus E1A and SV40 T-antigen, in particular by targeting the pRb tumor suppressor. HPV 16 E7 forms spherical oligomers that display chaperone activity in thermal denaturation and chemical refolding assays of two model polypeptide substrates, citrate synthase and luciferase, and it does so at substoichiometric concentrations. We show that the E7 chaperone can stably bind model polypeptides and hold them in a state with significant tertiary structure, but does not bind the fully native proteins. The E7 oligomers bind native in vitro translated pRb without the requirement of it being unfolded, since the N-terminal domain of E7 containing the LXCXE binding motif is exposed. The N-terminal domain of E7 can interfere with pRb binding but not with the chaperone activity, which requires the C-terminal domain, as in most reported E7 activities. The ability to bind up to ∼72 molecules of pRb by the oligomeric E7 form could be important either for sequestering pRb from Rb-E2F complexes or for targeting it for proteasome degradation. Thus, both the dimeric and oligomeric chaperone forms of E7 can bind Rb and various potential targets. We do not know at present if the chaperone activity of E7 plays an essential role in the viral life cycle; however, a chaperone activity may explain the large number of cellular targets reported for this oncoprotein.Fil: Alonso, Leonardo Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Smal, Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Garcia Alai, Maria M.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Chemes, Lucia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Salame, Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: de Prat Gay, Gonzalo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; Argentin

    Encoding multiple unnatural amino acids via evolution of a quadruplet-decoding ribosome

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    The in vivo, genetically programmed incorporation of designer amino acids allows the properties of proteins to be tailored with molecular precision. The Methanococcus jannaschii tyrosyl-transfer-RNA synthetase–tRNA_(CUA) (MjTyrRS–tRNA_(CUA)) and the Methanosarcina barkeri pyrrolysyl-tRNA synthetase–tRNA_(CUA) (MbPylRS–tRNA_(CUA)) orthogonal pairs have been evolved to incorporate a range of unnatural amino acids in response to the amber codon in Escherichia coli. However, the potential of synthetic genetic code expansion is generally limited to the low efficiency incorporation of a single type of unnatural amino acid at a time, because every triplet codon in the universal genetic code is used in encoding the synthesis of the proteome. To encode efficiently many distinct unnatural amino acids into proteins we require blank codons and mutually orthogonal aminoacyl-tRNA synthetase–tRNA pairs that recognize unnatural amino acids and decode the new codons. Here we synthetically evolve an orthogonal ribosome (ribo-Q1) that efficiently decodes a series of quadruplet codons and the amber codon, providing several blank codons on an orthogonal messenger RNA, which it specifically translates. By creating mutually orthogonal aminoacyl-tRNA synthetase–tRNA pairs and combining them with ribo-Q1 we direct the incorporation of distinct unnatural amino acids in response to two of the new blank codons on the orthogonal mRNA. Using this code, we genetically direct the formation of a specific, redox-insensitive, nanoscale protein cross-link by the bio-orthogonal cycloaddition of encoded azide- and alkyne-containing amino acids10. Because the synthetase–tRNA pairs used have been evolved to incorporate numerous unnatural amino acids, it will be possible to encode more than 200 unnatural amino acid combinations using this approach. As ribo-Q1 independently decodes a series of quadruplet codons, this work provides foundational technologies for the encoded synthesis and synthetic evolution of unnatural polymers in cells

    KAP Degradation by Calpain Is Associated with CK2 Phosphorylation and Provides a Novel Mechanism for Cyclosporine A-Induced Proximal Tubule Injury

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    The use of cyclosporine A (CsA) is limited by its severe nephrotoxicity that includes reversible vasoconstrictor effects and proximal tubule cell injury, the latter associated whith chronic kidney disease progression. The mechanisms of CsA-induced tubular injury, mainly on the S3 segment, have not been completely elucidated. Kidney androgen-regulated protein (KAP) is exclusively expressed in kidney proximal tubule cells, interacts with the CsA-binding protein cyclophilin B and its expression diminishes in kidneys of CsA-treated mice. Since we reported that KAP protects against CsA toxicity in cultured proximal tubule cells, we hypothesized that low KAP levels found in kidneys of CsA-treated mice might correlate with proximal tubule cell injury. To test this hypothesis, we used KAP Tg mice developed in our laboratory and showed that these mice are more resistant to CsA-induced tubular injury than control littermates. Furthermore, we found that calpain, which was activated by CsA in cell cultures and kidney, is involved in KAP degradation and observed that phosphorylation of serine and threonine residues found in KAP PEST sequences by protein kinase CK2 enhances KAP degradation by calpain. Moreover, we also observed that CK2 inhibition protected against CsA-induced cytotoxicity. These findings point to a novel mechanism for CsA-induced kidney toxicity that might be useful in developing therapeutic strategies aimed at preventing tubular cell damage while maintaining the immunosuppressive effects of CsA

    Massive X-ray screening reveals two allosteric drug binding sites of SARS-CoV-2 main protease

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    The coronavirus disease (COVID-19) caused by SARS-CoV-2 is creating tremendous health problems and economical challenges for mankind. To date, no effective drug is available to directly treat the disease and prevent virus spreading. In a search for a drug against COVID-19, we have performed a massive X-ray crystallographic screen of repurposing drug libraries containing 5953 individual compounds against the SARS-CoV-2 main protease (Mpro), which is a potent drug target as it is essential for the virus replication. In contrast to commonly applied X-ray fragment screening experiments with molecules of low complexity, our screen tested already approved drugs and drugs in clinical trials. From the three-dimensional protein structures, we identified 37 compounds binding to Mpro. In subsequent cell-based viral reduction assays, one peptidomimetic and five non-peptidic compounds showed antiviral activity at non-toxic concentrations. Interestingly, two compounds bind outside the active site to the native dimer interface in close proximity to the S1 binding pocket. Another compound binds in a cleft between the catalytic and dimerization domain of Mpro. Neither binding site is related to the enzymatic active site and both represent attractive targets for drug development against SARS-CoV-2. This X-ray screening approach thus has the potential to help deliver an approved drug on an accelerated time-scale for this and future pandemics

    X-ray screening identifies active site and allosteric inhibitors of SARS-CoV-2 main protease

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    The coronavirus disease (COVID-19) caused by SARS-CoV-2 is creating tremendous human suffering. To date, no effective drug is available to directly treat the disease. In a search for a drug against COVID-19, we have performed a high-throughput X-ray crystallographic screen of two repurposing drug libraries against the SARS-CoV-2 main protease (M^(pro)), which is essential for viral replication. In contrast to commonly applied X-ray fragment screening experiments with molecules of low complexity, our screen tested already approved drugs and drugs in clinical trials. From the three-dimensional protein structures, we identified 37 compounds that bind to M^(pro). In subsequent cell-based viral reduction assays, one peptidomimetic and six non-peptidic compounds showed antiviral activity at non-toxic concentrations. We identified two allosteric binding sites representing attractive targets for drug development against SARS-CoV-2

    The N-terminal module of HPV16 E7 is an intrinsically disordered domain that confers conformational and recognition plasticity to the oncoprotein

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    The HPV16 E7 oncoprotein is an extended dimer, with a stable and cooperative fold, but that displays properties of "natively unfolded" proteins. Two regions of conserved sequence are found in E7 proteins, where the N-terminus (1-40) includes the retinoblastoma tumor suppressor binding and casein kinase II phosphorylation sites. A fragment containing the highly acidic N-terminal half shows an apparently disordered conformation by far-UV-circular dichroism (CD) at neutral pH, and its hydrodynamic radius is much larger than a neutral peptide of the same length. Trifluoroethanol and micellar concentrations of sodium dodecyl sulfate stabilize a much more helical structure at pH 4.0 than at pH 7.5, while submicellar concentrations of the detergent yield a beta-strand. The shape, pH, and temperature dependence of the CD spectrum at pH 7.5 are indicative of a poly proline type II structure. This structure is stabilized by phosphorylation, which would translate into increased transforming activity in the cell. Thus, the intrinsically disordered properties of the N-terminal module of E7 are responsible for the structural plasticity of the oncoprotein. Although the domain is not a compact and cooperatively folded unit, it is a bona fide functional domain, evolved to maintain a dynamic but extended structure in the cell. These properties allow adaptation to a variety of protein targets and expose the PEST degradation sequence that regulates its turnover in the cell, a modification of which leads to the accumulation of E7 species with consequences in the transformation processFil: Garcia Alai, Maria M.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Alonso, Leonardo Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: de Prat Gay, Gonzalo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; Argentin

    Information Day of Research Infrastructures EMBL and ELIXIR

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    Info Day of Research Infrastructures EMBL and ELIXIR took place on 14.9.2023, on the premises of the Comenius University Science Park. The event featured lectures from various research departments from the EMBL headquarters in Heidelberg. The event also included a presentation of EMBL's programmes for PhD students and young researchers. The Info Day presented the opportunities that EMBL offers to Slovak scientists together with specific scientific services. Information was also provided about the ELIXIR scientific infrastructure, which focuses on biological data, its processing, storage, sharing and analysis. Participants learned more about the opportunities that ELIXIR infrastructure can provide to the Slovak scientific community

    Information Day of Research Infrastructures EMBL and ELIXIR

    No full text
    Info Day of Research Infrastructures EMBL and ELIXIR took place on 14.9.2023, on the premises of the Comenius University Science Park. The event featured lectures from various research departments from the EMBL headquarters in Heidelberg. The event also included a presentation of EMBL's programmes for PhD students and young researchers. The Info Day presented the opportunities that EMBL offers to Slovak scientists together with specific scientific services. Information was also provided about the ELIXIR scientific infrastructure, which focuses on biological data, its processing, storage, sharing and analysis. Participants learned more about the opportunities that ELIXIR infrastructure can provide to the Slovak scientific community
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