On the Diversification of the Translation Apparatus across Eukaryotes

Diversity is one of the most remarkable features of living organisms. Current assessments of eukaryote biodiversity reaches 1.5 million species, but the true figure could be several times that number. Diversity is ingrained in all stages and echelons of life, namely, the occupancy of ecological niches, behavioral patterns, body plans and organismal complexity, as well as metabolic needs and genetics. In this review, we will discuss that diversity also exists in a key biochemical process, translation, across eukaryotes. Translation is a fundamental process for all forms of life, and the basic components and mechanisms of translation in eukaryotes have been largely established upon the study of traditional, so-called model organisms. By using modern genome-wide, high-throughput technologies, recent studies of many nonmodel eukaryotes have unveiled a surprising diversity in the configuration of the translation apparatus across eukaryotes, showing that this apparatus is far from being evolutionarily static. For some of the components of this machinery, functional differences between different species have also been found. The recent research reviewed in this article highlights the molecular and functional diversification the translational machinery has undergone during eukaryotic evolution. A better understanding of all aspects of organismal diversity is key to a more profound knowledge of life

The Distribution of eIF4E-Family Members across Insecta

Insects are part of the earliest faunas that invaded terrestrial environments and are the first organisms that evolved controlled flight. Nowadays, insects are the most diverse animal group on the planet and comprise the majority of extant animal species described. Moreover, they have a huge impact in the biosphere as well as in all aspects of human life and economy; therefore understanding all aspects of insect biology is of great importance. In insects, as in all cells, translation is a fundamental process for gene expression. However, translation in insects has been mostly studied only in the model organism Drosophila melanogaster. We used all publicly available genomic sequences to investigate in insects the distribution of the genes encoding the cap-binding protein eIF4E, a protein that plays a crucial role in eukaryotic translation. We found that there is a diversity of multiple ortholog genes encoding eIF4E isoforms within the genus Drosophila. In striking contrast, insects outside this genus contain only a single eIF4E gene, related to D. melanogaster eIF4E-1. We also found that all insect species here analyzed contain only one Class II gene, termed 4E-HP. We discuss the possible evolutionary causes originating the multiplicity of eIF4E genes within the genus Drosophila

Procedimiento para el pago y cobro de la cuota sindical, en la ley 24.642. Su inconstitucionalidad

La ley 24.642 establece el denominado procedimiento de ejecución o apremio, a los efectos de percibir, por parte de la Asociación Sindical, la denominada cuota de contribución gremial que efectúa el afiliado, y que retiene el empleador. Este sistema establece que en caso de adeudarse la o las cuotas, el sindicato puede ejecutar al empleador si omitió retenerlas. Este título ejecutivo por el cual el sindicato inicia la ejecución, pide embargo y cobra las cuotas de afiliación impagas, con defensas muy limitadas del deudor La norma en cuestión al margen de equiparar los efectos procesales al juicio de apremio (art. 5º), fija competencia distintas y optativas, a criterio claro está del ejecutante (Asociación Sindical) en la que expresamente en los ámbitos provinciales, se ha excluido a la Justicia del Trabajo.La ley 24.642 establece el denominado procedimiento de ejecución o apremio, a los efectos de percibir, por parte de la Asociación Sindical, la denominada cuota de contribución gremial que efectúa el afiliado, y que retiene el empleador. Este sistema establece que en caso de adeudarse la o las cuotas, el sindicato puede ejecutar al empleador si omitió retenerlas. Este título ejecutivo por el cual el sindicato inicia la ejecución, pide embargo y cobra las cuotas de afiliación impagas, con defensas muy limitadas del deudor La norma en cuestión al margen de equiparar los efectos procesales al juicio de apremio (art. 5º), fija competencia distintas y optativas, a criterio claro está del ejecutante (Asociación Sindical) en la que expresamente en los ámbitos provinciales, se ha excluido a la Justicia del Trabajo

Procedimento para pagamento e cobrança da contribuição sindical na Lei 24.642. Sua inconstitucionalidade

La ley 24.642 establece el denominado procedimiento de ejecución o apremio, a los efectos de percibir, por parte de la Asociación Sindical, la denominada cuota de contribución gremial que efectúa el afiliado, y que retiene el empleador. Este sistema establece que en caso de adeudarse la o las cuotas, el sindicato puede ejecutar al empleador si omitió retenerlas. Este título ejecutivo por el cual el sindicato inicia la ejecución, pide embargo y cobra las cuotas de afiliación impagas, con defensas muy limitadas del deudor La norma en cuestión al margen de equiparar los efectos procesales al juicio de apremio (art. 5º), fija competencia distintas y optativas, a criterio claro está del ejecutante (Asociación Sindical) en la que expresamente en los ámbitos provinciales, se ha excluido a la Justicia del Trabajo. Resulta inconstitucional la ley en cuestión, porque con su enunciado se arroga una facultad no delegada por los gobiernos provinciales al gobierno Federal.Law 24.642 establishes the enforcement procedure for the purpose of collecting, by the Trade Union, the union contribution fee that the affiliate performs, and which the employer retains. This system establishes that in the event of owing these installments, the Union can execute the employer if it failed to retain them. This executive title, by which the Union starts this procedure, asks for seizure and collects unpaid membership fees, has very limited defenses of the debtor. The law in question establishes different and optional competences, at the discretion of the performer in which, specifically in the provincial areas, Labor Justice has been excluded. This law is unconstitutional, because with its enunciation a power is entrusted and not delegated by the provincial governments to the Federal government.A Lei 24.642 estabelece o chamado procedimento de execução ou urgência, a fim de perceber, pela Associação Sindical, a denominada cota de contribuição gremial que o associado efetua, e que o empregador retém. Este sistema estabelece que no caso de endividar-se a ou as cotas, o sindicato pode embargar ao empregador se este omitiu as retenções. Este titulo executivo pelo qual o sindicato inicia a execução, pede confisco e cobra as cotas de afiliação não pagas, com defesas muito limitadas por parte do devedor. A norma em questão estabelece competências diferentes e opcionais, de acordo com o claro critério do executante em que, especificamente nas áreas provinciais, a Justiça do Trabalho foi excluída. A lei em questão é inconstitucional, porque com a sua enunciação é confiado um poder não delegado pelos governos provinciais ao governo federal.Facultad de Ciencias Jurídicas y Sociale

Procedimento para pagamento e cobrança da contribuição sindical na Lei 24.642. Sua inconstitucionalidade

La ley 24.642 establece el denominado procedimiento de ejecución o apremio, a los efectos de percibir, por parte de la Asociación Sindical, la denominada cuota de contribución gremial que efectúa el afiliado, y que retiene el empleador. Este sistema establece que en caso de adeudarse la o las cuotas, el sindicato puede ejecutar al empleador si omitió retenerlas. Este título ejecutivo por el cual el sindicato inicia la ejecución, pide embargo y cobra las cuotas de afiliación impagas, con defensas muy limitadas del deudor La norma en cuestión al margen de equiparar los efectos procesales al juicio de apremio (art. 5º), fija competencia distintas y optativas, a criterio claro está del ejecutante (Asociación Sindical) en la que expresamente en los ámbitos provinciales, se ha excluido a la Justicia del Trabajo. Resulta inconstitucional la ley en cuestión, porque con su enunciado se arroga una facultad no delegada por los gobiernos provinciales al gobierno Federal.Law 24.642 establishes the enforcement procedure for the purpose of collecting, by the Trade Union, the union contribution fee that the affiliate performs, and which the employer retains. This system establishes that in the event of owing these installments, the Union can execute the employer if it failed to retain them. This executive title, by which the Union starts this procedure, asks for seizure and collects unpaid membership fees, has very limited defenses of the debtor. The law in question establishes different and optional competences, at the discretion of the performer in which, specifically in the provincial areas, Labor Justice has been excluded. This law is unconstitutional, because with its enunciation a power is entrusted and not delegated by the provincial governments to the Federal government.A Lei 24.642 estabelece o chamado procedimento de execução ou urgência, a fim de perceber, pela Associação Sindical, a denominada cota de contribuição gremial que o associado efetua, e que o empregador retém. Este sistema estabelece que no caso de endividar-se a ou as cotas, o sindicato pode embargar ao empregador se este omitiu as retenções. Este titulo executivo pelo qual o sindicato inicia a execução, pede confisco e cobra as cotas de afiliação não pagas, com defesas muito limitadas por parte do devedor. A norma em questão estabelece competências diferentes e opcionais, de acordo com o claro critério do executante em que, especificamente nas áreas provinciais, a Justiça do Trabalho foi excluída. A lei em questão é inconstitucional, porque com a sua enunciação é confiado um poder não delegado pelos governos provinciais ao governo federal.Facultad de Ciencias Jurídicas y Sociale

Procedimento para pagamento e cobrança da contribuição sindical na Lei 24.642. Sua inconstitucionalidade

La ley 24.642 establece el denominado procedimiento de ejecución o apremio, a los efectos de percibir, por parte de la Asociación Sindical, la denominada cuota de contribución gremial que efectúa el afiliado, y que retiene el empleador. Este sistema establece que en caso de adeudarse la o las cuotas, el sindicato puede ejecutar al empleador si omitió retenerlas. Este título ejecutivo por el cual el sindicato inicia la ejecución, pide embargo y cobra las cuotas de afiliación impagas, con defensas muy limitadas del deudor La norma en cuestión al margen de equiparar los efectos procesales al juicio de apremio (art. 5º), fija competencia distintas y optativas, a criterio claro está del ejecutante (Asociación Sindical) en la que expresamente en los ámbitos provinciales, se ha excluido a la Justicia del Trabajo. Resulta inconstitucional la ley en cuestión, porque con su enunciado se arroga una facultad no delegada por los gobiernos provinciales al gobierno Federal.Law 24.642 establishes the enforcement procedure for the purpose of collecting, by the Trade Union, the union contribution fee that the affiliate performs, and which the employer retains. This system establishes that in the event of owing these installments, the Union can execute the employer if it failed to retain them. This executive title, by which the Union starts this procedure, asks for seizure and collects unpaid membership fees, has very limited defenses of the debtor. The law in question establishes different and optional competences, at the discretion of the performer in which, specifically in the provincial areas, Labor Justice has been excluded. This law is unconstitutional, because with its enunciation a power is entrusted and not delegated by the provincial governments to the Federal government.A Lei 24.642 estabelece o chamado procedimento de execução ou urgência, a fim de perceber, pela Associação Sindical, a denominada cota de contribuição gremial que o associado efetua, e que o empregador retém. Este sistema estabelece que no caso de endividar-se a ou as cotas, o sindicato pode embargar ao empregador se este omitiu as retenções. Este titulo executivo pelo qual o sindicato inicia a execução, pede confisco e cobra as cotas de afiliação não pagas, com defesas muito limitadas por parte do devedor. A norma em questão estabelece competências diferentes e opcionais, de acordo com o claro critério do executante em que, especificamente nas áreas provinciais, a Justiça do Trabalho foi excluída. A lei em questão é inconstitucional, porque com a sua enunciação é confiado um poder não delegado pelos governos provinciais ao governo federal.Facultad de Ciencias Jurídicas y Sociale

Internal ribosome entry site drives cap-independent translation of reaper and heat shock protein 70 mRNAs in Drosophila embryos

Translation is a sensitive regulatory step during cellular stress and the apoptosis response. Under such conditions, cap-dependent translation is reduced and internal ribosome entry site (IRES)-dependent translation plays a major role. However, many aspects of how mRNAs are translated under stress remain to be elucidated. Here we report that reaper mRNA, a pro-apoptotic gene from Drosophila melanogaster, is translated in a cap-independent manner. In Drosophila mutant embryos devoid of the eukaryotic initiation factor 4E (eIF4E), reaper transcription is induced and apoptosis proceeds. In vitro translation experiments using wild-type and eIF4E mutant embryonic extracts show that reporter mRNA bearing reaper 5′ untranslated region (UTR) is effectively translated in a cap-independent manner. The 5′UTR of reaper exhibits a high degree of similarity with that of Drosophila heat shock protein 70 mRNA, and both display IRES activity. Studies of mRNA association to polysomes in embryos indicate that both reaper and heat shock protein 70 70 mRNAs are recruited to polysomes under apoptosis or thermal stress. Our data suggest that heat shock protein 70 70 and reaper, two antagonizing factors in apoptosis, use a similar mechanism for protein synthesis.Facultad de Ciencias Exacta

Cap binding-independent recruitment of eIF4E to cytoplasmic foci

Eukaryotic translation initiation factor 4E (eIF4E) is required for cap-dependent initiation. In addition, eIF4E occurs in cytoplasmic foci such as processing bodies (PB) and stress granules (SG). We examined the role of key functional amino acid residues of eIF4E in the recruitment of this protein to cytoplasmic foci. We demonstrate that tryptophan residues required for mRNA cap recognition are not required for the recruitment of eIF4E to SG or PB. We show that a tryptophan residue required for protein-protein interactions is essential for the accumulation of eIF4E in granules. Moreover, we show, by the analysis of two Drosophila eIF4E isoforms, that the tryptophan residue is the common feature for eIF4E for the transfer of active mRNA from polysomes to other ribonucleoprotein particles in the cytoplasm. This residue resides in a putative interaction domain different than the eIF4E-BP domain. We conclude that protein-protein interactions rather than interactions with the mRNA are essential for the recruitment of eIF4E and for a putative nucleation function.Facultad de Ciencias Exacta

Functional analysis of seven genes encoding eight translation initiation factor 4E (eIF4E) isoforms in Drosophila

The Drosophila genome-sequencing project has revealed a total of seven genes encoding eight eukaryotic initiation factor 4E (eIF4E) isoforms. Four of them (eIF4E-1,2, eIF4E-3, eIF4E-4 and eIF4E-5) share exon/intron structure in their carboxy-terminal part and form a cluster in the genome. All eIF4E isoforms bind to the cap (m7GpppN) structure. All of them, except eIF4E-6 and eIF4E-8 were able to interact with Drosophila eIF4G or eIF4E-binding protein (4E-BP). eIF4E-1, eIF4E-2, eIF4E-3, eIF4E-4 and eIF4E-7 rescued a yeast eIF4E-deficient mutant in vivo. Only eIF4E-1 mRNAs and, at a significantly lower level, eIF4E3 and eIF4E-8 are expressed in embryos and throughout the life cycle of the fly. The transcripts of the remaining isoforms were detected from the third instar larvae onwards. This indicates the cap-binding activity relies mostly on eIF4E-1 during embryogenesis. This agrees with the proteomic analysis of the eIF4F complex purified from embryos and with the rescue of l(3)67Af, an embryonic lethal mutant for the eIF4E-1,2 gene, by transgenic expression of eIF4E-1. Overexpression of eIF4E-1 in wild-type embryos and eye imaginal discs results in phenotypic defects in a dose-dependent manner.Este documento tiene una corrección (ver documento relacionado).Facultad de Ciencias Exacta