• El proyecto LIFE LEMNA presenta el primer prototipo semiindustrial de Europa basado en la tecnología de cultivo de lenteja de agua (Lemna) para la recuperación de nutrientes contenidos en los purines excedentarios de porcino.

• La instalación, de 250 m², puede producir más de 17t de biomasa/ha·año, con una productividad de proteína de origen vegetal 6-7 veces mayor que la obtenida en el cultivo de soja

• La lenteja de agua es una pequeña planta acuática menor de un cm, flotante, de forma circular y de color verde hierba intenso, que es capaz de absorber los nutrientes contenidos en los residuos ganaderos de forma muy eficiente y transformarlos en una biomasa rica en proteínas.

El proyecto europeo LIFE LEMNA busca soluciones que reduzcan el impacto medioambiental generado por la acumulación de nutrientes en los purines excedentarios de la ganadería intensiva. Encontrar soluciones ambiental y económicamente viables para estos materiales es una prioridad en España y el resto de la UE debido a la problemática de contaminación por nitratos y emisiones de CO2 asociada. Además, reducir la huella ambiental de los productos cárnicos va a resultar un factor de competitividad en el futuro por lo que el sector necesita encontrar soluciones.

Para ayudar a resolver este problema, el centro tecnológico AINIA, junto con el Centro Nacional de Biotecnología (CNB) perteneciente al Consejo Superior de Investigaciones Científicas (CSIC) y las empresa Porgaporcs y ECOBIOGAS, han desarrollado la primera planta piloto a escala semi industrial de Europa que permite recuperar los nutrientes (nitrógeno, fósforo) de los purines, y reutilizarlos en la propia zona en la que se generan.

Plant, Cell & Environment 08 July 2019

J Ochoa de Eribe, A Valli, M Martín‐Trillo, C Simón‐Mateo, JA García, B Rodamilans.

Abstract

Plants use RNA silencing as a strong defensive barrier against virus challenges, and viruses counteract this defence by using RNA silencing suppressors (RSSs). With the objective of identifying host factors helping either the plant or the virus in this interaction, we have performed a yeast two hybrid screen using P1b, the RSS protein of the ipomovirus Cucumber vein yellowing virus (CVYV, family Potyviridae), as a bait. The C‐8 sterol isomerase HYDRA1 (HYD1), an enzyme involved in isoprenoid biosynthesis and cell membrane biology, and required for RNA silencing, was isolated in this screen. The interaction between CVYV P1b and HYD1 was confirmed in planta by Bimolecular Fluorescence Complementation assays. We demonstrated that HYD1 enhances RNA silencing activity in the presence of CVYV P1b in an agroinfiltration assay. Moreover, expression of HYD1 inhibited the infection of the potyvirus Plum pox virus, especially when antiviral RNA silencing was boosted by high temperature or by co‐expression of homologous sequences. Our results reinforce previous evidence highlighting the relevance of particular composition and structure of cellular membranes for RNA silencing and viral infection. We report a new interaction of an RSS protein from the Potyviridae family with a member of the isoprenoid biosynthetic pathway.

https://doi.org/10.1111/pce.13610

• Las chaperonas moleculares son clave para el equilibrio entre la síntesis y degradación de las proteínas celulares
• Para analizar la función de estos complejos y conocer su estructura, los científicos han empleado el criomicroscopio electrónico del Centro Nacional de Biotecnología del CSIC

Un trabajo codirigido por investigadores del Centro Nacional de Biotecnología del Consejo Superior de Investigaciones Científicas (CSIC) ha determinado el mecanismo de funcionamiento del complejo CCT, una de las chaperonas moleculares más importantes en organismos eucariotas. Los científicos, que publican sus resultados en el último número de la revista Nature Communications, han empleado un criomicroscopio electrónico de última generación.

Nature Communications 10, Article number: 2865 (2019)

Jorge Cuéllar, W. Grant Ludlam, Nicole C. Tensmeyer, Takuma Aoba, Madhura Dhavale, César Santiago, M. Teresa Bueno-Carrasco, Michael J. Mann, Rebecca L. Plimpton, Aman Makaju, Sarah Franklin, Barry M. Willardson & José M. Valpuesta.

Abstract

The mechanistic target of rapamycin (mTOR) kinase forms two multi-protein signaling complexes, mTORC1 and mTORC2, which are master regulators of cell growth, metabolism, survival and autophagy. Two of the subunits of these complexes are mLST8 and Raptor, β-propeller proteins that stabilize the mTOR kinase and recruit substrates, respectively. Here we report that the eukaryotic chaperonin CCT plays a key role in mTORC assembly and signaling by folding both mLST8 and Raptor. A high resolution (4.0 Å) cryo-EM structure of the human mLST8-CCT intermediate isolated directly from cells shows mLST8 in a near-native state bound to CCT deep within the folding chamber between the two CCT rings, and interacting mainly with the disordered N- and C-termini of specific CCT subunits of both rings. These findings describe a unique function of CCT in mTORC assembly and a distinct binding site in CCT for mLST8, far from those found for similar β-propeller proteins.

Investigadores del CSIC colaboran en un estudio internacional sobre el origen y la evolución de las variedades europeas de la patata, con la ayuda de las colecciones históricas de los herbarios. La adaptación fuera de su región de origen puede haber seguido rutas similares en Europa y el Sur de América.

El congreso de la Sociedad Española de Virología (SEV) de 2019 se ha celebrado en Barcelona entre el 9 y 12 de junio. En esta edición, dos investigadores del CNB-CSIC han resultado galardonados con los premios al Virólogo Senior y Virólogo Joven que otorga la SEV.

Plant Cell. 2019 Jun;31(6):1222-1237.

Méndez-Vigo B, Ausín I, Zhu W2, Mollá-Morales A, Balasubramanian S, Alonso-Blanco C.

Abstract

Understanding how plants adapt to ambient temperatures has become a major challenge prompted by global climate change. This has led to the identification of several genes regulating the thermal plasticity of plant growth and flowering time. However, the mechanisms accounting for the natural variation and evolution of such developmental plasticity remain mostly unknown. In this study, we determined that natural variation at ICARUS2 (ICA2), which interacts genetically with its homolog ICA1, alters growth and flowering time plasticity in relation to temperature in Arabidopsis (Arabidopsis thaliana). Transgenic analyses demonstrated multiple functional effects for ICA2 and supported the notion that structural polymorphisms in ICA2 likely underlie its natural variation. Two major ICA2 haplogroups carrying distinct functionally active alleles showed high frequency, strong geographic structure, and significant associations with climatic variables related to annual and daily fluctuations in temperature. Genome analyses across the plant phylogeny indicated that the prevalent plant ICA genes encoding two tRNAHis guanylyl transferase 1 units evolved ∼120 million years ago during the early divergence of mono- and dicotyledonous clades. In addition, ICA1/ICA2 duplication occurred specifically in the Camelineae tribe (Brassicaceae). Thus, ICA2 appears to be ubiquitous across plant evolution and likely contributes to climate adaptation through modifications of thermal developmental plasticity in Arabidopsis.

doi: 10.1105/tpc.18.00938. Epub 2019 Apr 16

• Identificados en ‘Arabidopsis thaliana’ los genes que regulan un nuevo mecanismo de adaptación a altas temperaturas
• La interacción genética entre dos genes duplicados regula el ciclo de la división celular, según un estudio del CSIC

Las plantas están sometidas a fluctuaciones de temperatura diarias y estacionales que provocan cambios en sus patrones de expresión genética.  Esta plasticidad les permite adaptarse a las condiciones ambientales mediante cambios en su ritmo de crecimiento y tiempo de floración. 

Entender cómo las plantas de diferentes regiones del mundo se adaptan a las temperaturas del ambiente en el que crecen es el objetivo de las investigaciones de un equipo de científicos del Consejo Superior de Investigaciones Científicas (CSIC) en el Centro Nacional de Biotecnología. En su último trabajo, publicado en la revista The Plant Cell, los investigadores han identificado en la planta modelo Arabidopsis thaliana dos genes duplicados, ICARUS1 y 2 (ICA1 e ICA2), que están implicados en la regulación de la respuesta térmica del desarrollo de las plantas.

J Immunother Cancer. 2019 Jun 13;7(1):151.

Ogando J, Sáez ME, Santos J, Nuevo-Tapioles C, Gut M, Esteve-Codina A, Heath S, González-Pérez A, Cuezva JM, Lacalle RA, Mañes S

Abstract

BACKGROUND: Binding of the programmed death-1 (PD-1) receptor to its ligands (PD-L1/2) transduces inhibitory signals that promote exhaustion of activated T cells. Blockade of the PD-1 pathway is widely used for cancer treatment, yet the inhibitory signals transduced by PD-1 in T cells remain elusive.

METHODS: Expression profiles of human CD8+ T cells in resting, activated (CD3 + CD28) and PD-1-stimulated cells (CD3 + CD28 + PD-L1-Fc) conditions were evaluated by RNA-seq. Bioinformatic analyses were used to identify signaling pathways differentially regulated in PD-1-stimulated cells. Metabolic analyses were performed with SeaHorse technology, and mitochondrial ultrastructure was determined by transmission electron microscopy. PD-1-regulated mitochondrial genes were silenced using short-hairpin RNA in primary cells. Blue native gel electrophoresis was used to determine respiratory supercomplex assembly.

RESULTS: PD-1 engagement in human CD8+ T cells triggers a specific, progressive genetic program different from that found in resting cells. Gene ontology identified metabolic processes, including glycolysis and oxidative phosphorylation (OXPHOS), as the main pathways targeted by PD-1. We observed severe functional and structural alterations in the mitochondria of PD-1-stimulated cells, including a reduction in the number and length of mitochondrial cristae. These cristae alterations were associated with reduced expression of CHCHD3 and CHCHD10, two proteins that form part of the mitochondrial contact site and cristae organizing system (MICOS). Although PD-1-stimulated cells showed severe cristae alterations, assembly of respiratory supercomplexes was unexpectedly greater in these cells than in activated T cells. CHCHD3 silencing in primary CD8+ T cells recapitulated some effects induced by PD-1 stimulation, including reduced mitochondrial polarization and interferon-γ production following T cell activation with anti-CD3 and -CD28 activating antibodies.

CONCLUSIONS: Our results suggest that mitochondria are the main targets of PD-1 inhibitory activity. PD-1 reprograms CD8+ T cell metabolism for efficient use of fatty acid oxidation; this mitochondrial phenotype might explain the long-lived phenotype of PD-1-engaged T cells.