The THO complex as a key mRNP biogenesis factor in development and cell differentiation

The THO complex is a key component in the co-transcriptional formation of messenger ribonucleoparticles that are competent to be exported from the nucleus, yet its precise function is unknown. A recent study in BMC Biology on the role of the THOC5 subunit in cell physiology and mouse development provides new clues to the role of the THO complex in cell differentiation

Poder de las patentes y bioprecariedad: cuestiones de legalidad y legitimidad

[spa] El objetivo de la presente investigación es analizar el poder de las patentes y su papel en la confrontación actual entre el derecho a la salud (pública) y los derechos a la propiedad intelectual (patentes), ambos reconocidos por la Declaración Universal de Derechos Humanos. Este poder se basa en el control monopolístico de la (material biológico) mediante las patentes biotecnológicas o “patentes de la vida”. La Oficina Española de Patentes y Marcas define las patentes como “un título que reconoce el derecho de explotar en exclusiva una invención, impidiendo a otros su fabricación, venta o utilización sin consentimiento del titular”. El “contrato de patentes” implica que el titular de una patente obtiene un monopolio para recuperar la inversión realizada en investigación a cambio de divulgar la invención. Sin embargo, demostraremos que esta afirmación no siempre es cierta ya que este monopolio permite establecer precios elevados a los productos patentados, condenando a miles de personas a lo que denominamos “bioprecariedad” entendida como la falta de acceso a productos patentados, básicos para la supervivencia como alimentos, semillas, medicamentos, tratamientos o kits de diagnóstico. Analizaremos el actual sistema de propiedad intelectual a nivel mundial, encarnado por los Acuerdos sobre Aspectos de los derechos de propiedad intelectual relacionados con el comercio (ADPIC) de la Organización Mundial del Comercio y a nivel europeo, la patente unitaria, así como el papel del bioderecho para proponer alternativas al mismo. Propondremos un marco normativo y comités de ética de patentes que sirvan para poner límites éticos a las patentes según los criterios de responsabilidad y cautela; justicia global; y capacidades y desarrollo humano. La conclusión de la presente investigación es que la vida se ha mercantilizado por medio de las patentes y se ha convertido en un “producto” sometido a las leyes del mercado con el consiguiente impacto en la salud pública y bioprecariedad.[eng] This research is focused on the analysis of the power of patents and their role in the current confrontation between the right to (public) health and the right to Intellectual property (patents), which are both human rights recognised by the Universal Declaration of Human Rights. This power is based on the monopoly controlling life (biological material) by means of biotechonological patents or “patents of life”. The Spanish Patent and Trademark Office defines a patent as “a title recognising the right to exclusively exploit an invention, preventing third parties from manufacturing, selling or using it without prior consent of the owner”. The “patent contract” implies that the patent owner obtains a monopoly to recover the investment in research and in exchange, he/she must disclose the invention. However, in the present paper we will prove that this statement is not always true given that this monopoly involves high prices for patented products, which condemns thousands of people to what we call “bioprecariousness” defined as the lack of access to basic patented products for surviving as food, seeds, medicines, treatments and tests. We will analyse the current IP legislation worldwide with the TRIPS agreement of the World Trade Organization, the European legislation with the unitary patent, and the role of bioright in providing alternatives thereto. We will provide a new ethical framework and ethical patent committees aimed at setting ethical limits to patents according to the criteria of responsibility and caution; global justice, and capabilities and human development. The conclusion of this research is that life has been turned into a “commodity” subject to the laws of the market with the resulting impact on public health and bioprecariousness

Bioprecariedad: violencia estructural contra la vida en la pandemia del COVID-19

El objetivo del presente artículo es analizar el impacto de las patentes en la salud pública durante la pandemia del COVID-19. La Oficina Española de Patentes y Marcas define las patentes como “un título que reconoce el derecho de explotar en exclusiva una invención, impidiendo a otros su fabricación, venta o utilización sin consentimiento del titular”. Este monopolio permite establecer precios elevados a los productos patentados, condenando a miles de personas a lo que denominamos bioprecariedad entendida como violencia estructural contra la vida por la falta de acceso a productos patentados básicos para la supervivencia (, semillas, medicamentos antivirales y vacunas para el COVID-19, tratamientos o kits de diagnóstico). En el contexto de la pandemia, la bioprecariedad se ha puesto de manifiesto en la ausencia de vacunas en los países en vías de desarrollo. Para limitar el poder de las patentes y amortiguar los efectos de la bioprecariedad, proponemos crear un marco normativo aplicable en comités de ética de patentes que concedan patentes no solo según criterios técnicos, sino éticos tales como: responsabilidad y cautela; justicia global; y capacidades y desarrollo humano

EXOSC10 is required for RPA assembly and controlled DNA end resection at DNA double-strand breaks

The exosome is a ribonucleolytic complex that plays important roles in RNA metabolism. Here we show that the exosome is necessary for the repair of DNA double-strand breaks (DSBs) in human cells and that RNA clearance is an essential step in homologous recombination. Transcription of DSB-flanking sequences results in the production of damage-induced long non-coding RNAs (dilncRNAs) that engage in DNA-RNA hybrid formation. Depletion of EXOSC10, an exosome catalytic subunit, leads to increased dilncRNA and DNA-RNA hybrid levels. Moreover, the targeting of the ssDNA-binding protein RPA to sites of DNA damage is impaired whereas DNA end resection is hyper-stimulated in EXOSC10-depleted cells. The DNA end resection deregulation is abolished by transcription inhibitors, and RNase H1 overexpression restores the RPA recruitment defect caused by EXOSC10 depletion, which suggests that RNA clearance of newly synthesized dilncRNAs is required for RPA recruitment, controlled DNA end resection and assembly of the homologous recombination machinery.España, Ministerio de Economía y Competitividad R + D + I project grant SAF2016-74855-P to P.

New Tools to Study DNA Double-Strand Break Repair Pathway Choice

A broken DNA molecule is difficult to repair, highly mutagenic, and extremely cytotoxic. Such breaks can be repaired by homology-independent or homology-directed mechanisms. Little is known about the network that controls the repair pathway choice except that a licensing step for homology-mediated repair exists, called DNA-end resection. The choice between these two repair pathways is a key event for genomic stability maintenance, and an imbalance of the ratio is directly linked with human diseases, including cancer. Here we present novel reporters to study the balance between both repair options in human cells. In these systems, a double-strand break can be alternatively repaired by homology-independent or -dependent mechanisms, leading to the accumulation of distinct fluorescent proteins. These reporters thus allow the balance between both repair pathways to be analyzed in different experimental setups. We validated the reporters by analyzing the effect of protein downregulation of the DNA end resection and non-homologous end-joining pathways. Finally, we analyzed the role of the DNA damage response on double-strand break (DSB) repair mechanism selection. Our reporters could be used in the future to understand the roles of specific factors, whole pathways, or drugs in DSB repair pathway choice, or for genome-wide screening. Moreover, our findings can be applied to increase gene-targeting efficiency, making it a beneficial tool for a broad audience in the biological sciences. © 2013 Gomez-Cabello et al.This work has been funded by a R+D+I grant from the Spanish Ministry of Economy and Competitivity (SAF2010-14877) and an European Research Council (ERC) Starting Grant (DSBRECA).Peer Reviewe

New tools to study DNA double-strand break repair pathway choice

A broken DNA molecule is difficult to repair, highly mutagenic, and extremely cytotoxic. Such breaks can be repaired by homology-independent or homology-directed mechanisms. Little is known about the network that controls the repair pathway choice except that a licensing step for homology-mediated repair exists, called DNA-end resection. The choice between these two repair pathways is a key event for genomic stability maintenance, and an imbalance of the ratio is directly linked with human diseases, including cancer. Here we present novel reporters to study the balance between both repair options in human cells. In these systems, a double-strand break can be alternatively repaired by homology-independent or -dependent mechanisms, leading to the accumulation of distinct fluorescent proteins. These reporters thus allow the balance between both repair pathways to be analyzed in different experimental setups. We validated the reporters by analyzing the effect of protein downregulation of the DNA end resection and non-homologous end-joining pathways. Finally, we analyzed the role of the DNA damage response on double-strand break (DSB) repair mechanism selection. Our reporters could be used in the future to understand the roles of specific factors, whole pathways, or drugs in DSB repair pathway choice, or for genome-wide screening. Moreover, our findings can be applied to increase gene-targeting efficiency, making it a beneficial tool for a broad audience in the biological sciences

Molecular evidence that the eukaryotic THO/TREX complex is required for efficient transcription elongation

THO/TREX is a conserved eukaryotic complex formed by the core THO complex plus proteins involved in mRNA metabolism and export such as Sub2 and Yra1. Mutations in any of the THO/TREX structural genes cause pleiotropic phenotypes such as transcription impairment, increased transcription-associated recombination, and mRNA export defects. To assay the relevance of THO/TREX complex in transcription, we performed in vitro transcription elongation assays in mutant cell extracts using supercoiled DNA templates containing two G-less cassettes. With these assays, we demonstrate that hpr1Δ, tho2Δ, and mft1Δ mutants of the THO complex and sub2 mutants show significant reductions in the efficiency of transcription elongation. The mRNA expression defect of hpr1Δ mutants was not due to an increase in mRNA decay, as determined by mRNA half-life measurements and mRNA time course accumulation experiments in the absence of Rrp6p exoribonuclease. This work demonstrates that THO and Sub2 are required for efficient transcription elongation, providing further evidence for the coupling between transcription and mRNA metabolism and export.Ministerio de Ciencia y Tecnología BMC2000-0439Human Frontier Science Program RG1999/007

ADAR-mediated RNA editing of DNA:RNA hybrids is required for DNA double strand break repair

The maintenance of genomic stability requires the coordination of multiple cellular tasks upon the appearance of DNA lesions. RNA editing, the post-transcriptional sequence alteration of RNA, has a profound effect on cell homeostasis, but its implication in the response to DNA damage was not previously explored. Here we show that, in response to DNA breaks, an overall change of the Adenosine-to-Inosine RNA editing is observed, a phenomenon we call the RNA Editing DAmage Response (REDAR). REDAR relies on the checkpoint kinase ATR and the recombination factor CtIP. Moreover, depletion of the RNA editing enzyme ADAR2 renders cells hypersensitive to genotoxic agents, increases genomic instability and hampers homologous recombination by impairing DNA resection. Such a role of ADAR2 in DNA repair goes beyond the recoding of specific transcripts, but depends on ADAR2 editing DNA:RNA hybrids to ease their dissolution.This work was funded by an R + D + I grant from the Agencia Estatal de Investigación PID2019-104195GB-I00/ AEI/10.13039/501100011033 (P.H.), R + D + I grants from the Spanish Ministry of Economy and Competitiveness (SAF2016-74855-P to P.H. and BFU2016-75058-P to A.A.), the European Research Council (ERC2014 AdG669898 TARLOOP to A.A.), the Associazione Italiana Ricerca sul Cancro-AIRC (AIRC IG 22080 to A.G.), The Swedish Research Council (grants 2015-04553 to N.V.), The Swedish Cancer Society (grant CAN 2016/460 to N.V.) and the European Union (FEDER). AR is, and FM-N and RP-C were, funded with FPU fellowships from the Spanish Ministry of Education and S.S. by a Juan de la Cierva contract from the Spanish Ministry of Economy and Competitiveness. J.D.P. and M.E-C. were supported by the Department of Molecular Biosciences, The Wenner-Gren Institute at Stockholm University. J.D-P. and R.P-C. were recipients of short-term EMBO fellowships (STF- 7513-2018 and STF-7764-2018). The mutational results shown here are in whole or part based upon the data generated by the TCGA Research Network: https://www.cancer.gov/tcga. All the bioinformatic analyses were performed using custom scripts that were run on the High performance computing cluster provided by the Centro Informático Cienti ́fico de Andalucía (CICA). CABIMER is supported by the regional government of Andalucia (Junta de Andalucía)

LipoBots : using liposomal vesicles as protective shell of urease-based nanomotors

Developing self-powered nanomotors made of biocompatible and functional components is of paramount importance in future biomedical applications. Herein, the functional features of LipoBots (LBs) composed of a liposomal carrier containing urease enzymes for propulsion, including their protective properties against acidic conditions and their on-demand triggered activation, are reported. Given the functional nature of liposomes, enzymes can be either encapsulated or coated on the surface of the vesicles. The influence of the location of urease on motion dynamics is first studied, finding that the surface-urease LBs undergo self-propulsion whereas the encapsulated-urease LBs do not. However, adding a percolating agent present in the bile salts to the encapsulated-urease LBs triggers active motion. Moreover, it is found that when both types of nanomotors are exposed to a medium of similar pH found in the stomach, the surface-urease LBs lose activity and motion capabilities, while the encapsulated-urease LBs retain activity and mobility. The results for the protection enzyme activity through encapsulation within liposomes and in situ triggering of the motion of LBs upon exposure to bile salts may open new avenues for the use of liposome-based nanomotors in drug delivery, for example, in the gastrointestinal tract, where bile salts are naturally present in the intestine