Whitefly genomes contain ribotoxin coding genes acquired from plants

Ribosome inactivating proteins (RIPs) are RNA N-glycosidases that depurinate a specific adenine residue in the conserved sarcin/ricin loop of 28S rRNA. These enzymes are widely distributed among plants and bacteria. Previously, we have described for the first time RIP genes in mosquitoes belonging to the Culicidae family. We showed that these genes are derived from a single event of horizontal gene transfer (HGT) from a prokaryotic donor. Mosquito RIP genes are evolving under purifying selection, strongly suggesting that these toxins have acquired a functional role. In this work, we show the existence of two RIP encoding genes in the genome of the whitefly Bemisia tabaci, a hemiptera species belonging to the Aleyrodidae family distantly related to mosquitoes. Contamination artifacts were ruled out analyzing three independent B. tabaci genome databases. In contrast to mosquito RIPs, whitefly genes harbor introns and according to transcriptomic evidence are transcribed and spliced. Phylogeny and the taxonomic distribution strongly support that whitefly RIP genes are derived from an independent HGT event from a plant source. These results, along with our previous description of RIPs in Diptera, suggest that the acquired genes are functional in these insects and confer some fitness advantage.Fil: Lapadula, Walter Jesús. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Mascotti, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Juri Ayub, Maximiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentin

On the diversity of F420 -dependent oxidoreductases:A sequence- and structure-based classification

The F(420) deazaflavin cofactor is an intriguing molecule as it structurally resembles the canonical flavin cofactor, although behaves as a nicotinamide cofactor due to its obligate hydride‐transfer reactivity and similar low redox potential. Since its discovery, numerous enzymes relying on it have been described. The known deazaflavoproteins are taxonomically restricted to Archaea and Bacteria. The biochemistry of the deazaflavoenzymes is diverse and they exhibit great structural variability. In this study a thorough sequence and structural homology evolutionary analysis was performed in order to generate an overarching classification of the F(420)‐dependent oxidoreductases. Five different deazaflavoenzyme Classes (I–V) are described according to their structural folds as follows: Class I encompassing the TIM‐barrel F(420)‐dependent enzymes; Class II including the Rossmann fold F(420)‐dependent enzymes; Class III comprising the β‐roll F(420)‐dependent enzymes; Class IV which exclusively gathers the SH3 barrel F(420)‐dependent enzymes and Class V including the three layer ββα sandwich F(420)‐dependent enzymes. This classification provides a framework for the identification and biochemical characterization of novel deazaflavoenzymes

Ribosomes from Trypanosomatids: Unique Structural and Functional Properties

Trypanosomatids are a monophyletic group of protozoa that diverged early from the eukaryotic lineage, constituting valuable model organisms for studying variability in different highly conserved processes including protein synthesis. Moreover, several species of trypanosomatids are causing agents of endemic diseases in the third world. There are many evidences suggesting that translation in these organisms shows important differences with that of model organisms such as yeast and mammals. These unique features, which have a great potential relevance for both basic and applied research, will be discussed in this chapter.Fil: Juri Ayub, Maximiliano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Lapadula, Walter Jesús. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Hoebeke, Johan. Centre National de la Recherche Scientifique; FranciaFil: Smulski, Cristian Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina. Centre National de la Recherche Scientifique; Franci

Historia del taller: las abuelas, la genética y los Derechos Humanos

El taller que desarrollamos y que hemos ido construyendo a partir de las distintas experiencias tiene como objetivo narrar cómo a partir de la iniciativa de Abuelas surgió la posibilidad de desarrollar nuevos conocimientos científicos y técnicos para restituir la identidad de lxs nietxs apropiadxs por la última dictadura cívico-militar. El formato de taller, las temáticas desarrolladas desde distintos ángulos, como es el caso del concepto de identidad, y las actividades interactivas que se desarrollan, permite que los conocimientos abordados en el aula se enlacen con realidades fácilmente palpables y comprobables por lxs estudiantes en su contexto social. Esto no solo facilita la apropiación de conceptos por su anclaje con experiencias cotidianas, sino a comprender que la ciencia se desarrolla en medio de los procesos políticos, las normas sociales y los paradigmas de la época.Universidad Nacional de La Plat

Las Abuelas, la genética y los derechos humanos

El taller que desarrollamos y que hemos ido construyendo a partir de las distintas experiencias tiene como objetivo narrar cómo a partir de la iniciativa de Abuelas de Plaza de Mayo surgió la posibilidad de desarrollar nuevos conocimientos científicos y técnicos para restituir la identidad de lxs nietxs apropiadxs por la última dictadura cívico-militar. El taller esta destinado a estudiantes y docentes de instituciones educativas del nivel medio, donde compartimos como este adelanto técnico, generado a instancias de Abuelas, tuvo un efecto jurídico a nivel internacional en la consagración del Derecho a la Identidad (los así llamados “artículos argentinos” de la Convención sobre los Derechos del Niñx de Naciones Unidas). A su vez divulgamos de manera accesible los fundamentos básicos de los análisis genéticos empleados. Explicamos la importancia del Derecho a la Identidad en particular y de los Derechos Humanos en general, así como el principio de progresividad de los derechos. Y abordamos la importancia de la lucha de Abuelas para reparar no sólo historias personales o familiares, sino de la sociedad en su conjunto. Por ultimo, el cierre es un relato de nuestra compañera sobre la desaparición de su papá en el terrorismo de Estado.Universidad Nacional de La Plat

The trypanocidal activity of the alkaloid oliverine involves inhibition of DNA synthesis

The Trypanosoma cruzi parasite is an etiologic agent of the American trypanosomiasis called Chagas disease. This pathology affects more than 24 million persons and represents one of the most important public health problems in Latin America. Taking into account this, it is necessary the search of new antitrypanosomal agents that show a major level of efficacy and minor indexes of toxicity in affected patients. Vast source of them are the natural products from plants with enormous structural diversity. A particular type of these compounds is represented by aporphinoid alkaloids. In our experiments, anonaine (2), oliverine (3) and guatterine (5) displayed antitrypanosomal activity. The compound 3 showed the most important activity with an IC50 = 12.00 ± 0.36 μM. Its mechanism of action may include inhibition of DNA synthesis.Fil: Garro, Hugo Alejandro. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Química. Area de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Investigaciones en Tecnología Química; ArgentinaFil: Juri Ayub, Maximiliano. Universidad Nacional de San Luis. Facultad de Quimica, Bioquimica y Farmacia. Departamento de Bioquímica y Ciencias Biológicas; Argentina. Fundación Instituto Leloir; ArgentinaFil: Nieto, M.. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Química. Area de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Investigaciones en Tecnología Química; ArgentinaFil: Lucero Estrada, Cecilia Stella Marys. Universidad Nacional de San Luis. Facultad de Quimica, Bioquimica y Farmacia. Area Microbiologia; ArgentinaFil: Pungitore, Carlos Rodolfo. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Química. Area de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Investigaciones en Tecnología Química; ArgentinaFil: Tonn, Carlos Eugenio. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Química. Area de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto de Investigaciones en Tecnología Química; Argentin

Chopping and Changing: the Evolution of the Flavin-dependent Monooxygenases.

Flavin-dependent monooxygenases play a variety of key physiological roles and are also very powerful biotechnological tools. These enzymes have been classified into eight different classes (A-H) based on their sequences and biochemical features. By combining structural and sequence analysis, and phylogenetic inference, we have explored the evolutionary history of classes A, B, E, F, and G and demonstrate that their multidomain architectures reflect their phylogenetic relationships, suggesting that the main evolutionary steps in their divergence are likely to have arisen from the recruitment of different domains. Additionally, the functional divergence within in each class appears to have been the result of other mechanisms such as a complex set of single-point mutations. Our results reinforce the idea that a main constraint on the evolution of cofactor-dependent enzymes is the functional binding of the cofactor. Additionally, a remarkable feature of this family is that the sequence of the key flavin adenine dinucleotide-binding domain is split into at least two parts in all classes studied here. We propose a complex set of evolutionary events that gave rise to the origin of the different classes within this family

Selective Blockade of Trypanosomatid Protein Synthesis by a Recombinant Antibody Anti-Trypanosoma cruzi P2β Protein

The ribosomal P proteins are located on the stalk of the ribosomal large subunit and play a critical role during the elongation step of protein synthesis. The single chain recombinant antibody C5 (scFv C5) directed against the C-terminal region of the Trypanosoma cruzi P2β protein (TcP2β) recognizes the conserved C-terminal end of all T. cruzi ribosomal P proteins. Although this region is highly conserved among different species, surface plasmon resonance analysis showed that the scFv C5 possesses very low affinity for the corresponding mammalian epitope, despite having only one single amino-acid change. Crystallographic analysis, in silico modelization and NMR assays support the analysis, increasing our understanding on the structural basis of epitope specificity. In vitro protein synthesis experiments showed that scFv C5 was able to specifically block translation by T. cruzi and Crithidia fasciculata ribosomes, but virtually had no effect on Rattus norvegicus ribosomes. Therefore, we used the scFv C5 coding sequence to make inducible intrabodies in Trypanosoma brucei. Transgenic parasites showed a strong decrease in their growth rate after induction. These results strengthen the importance of the P protein C terminal regions for ribosomal translation activity and suggest that trypanosomatid ribosomal P proteins could be a possible target for selective therapeutic agents that could be derived from structural analysis of the scFv C5 antibody paratope

Production of recombinant enzymes of wide use for research

For biotechnological purposes, protein expression refers to the directed synthesis of large amounts of desired proteins. The aim of the present work was to produce reverse transcriptase Moloney murine Leukaemia Virus retro-transcriptase and Taq DNA polymerase, as bioactive products. In the present paper, we report the preparation of recombinant enzymes, expressed in E. coli strains. The enzymes produced exhibited quite good activity, compared with commercial enzymes, allowing us to replace the last ones for several lab applications. We are reporting changes and modifications to standard protocols described. The standard protocols were modified, i.e. for the purification step of Taq, a temperature dependent procedure was designed. The enzymes produced were used in different applications, such as PCR, RT-PCR, PCR Multiplex and RAPDs molecular markers

Production of recombinant enzymes of wide use for research

For biotechnological purposes, protein expression refers to the directed synthesis of large amounts of desired proteins. The aim of the present work was to produce reverse transcriptase Moloney murine Leukaemia Virus retro-transcriptase and Taq DNA polymerase, as bioactive products. In the present paper, we report the preparation of recombinant enzymes, expressed in E. coli strains. The enzymes produced exhibited quite good activity, compared with commercial enzymes, allowing us to replace the last ones for several lab applications. We are reporting changes and modifications to standard protocols described. The standard protocols were modified, i.e. for the purification step of Taq, a temperature dependent procedure was designed. The enzymes produced were used in different applications, such as PCR, RT-PCR, PCR Multiplex and RAPDs molecular markers