The p53 binding protein PDCD5 is not rate-limiting in DNA damage induced cell death

The tumour suppressor p53 is an important mediator of cell cycle arrest and apoptosis in response to DNA damage, acting mainly by transcriptional regulation of specific target genes. The exact details how p53 modulates this decision on a molecular basis is still incompletely understood. One mechanism of regulation is acetylation of p53 on lysine K120 by the histone-acetyltransferase Tip60, resulting in preferential transcription of proapoptotic target genes. PDCD5, a protein with reported pro-apoptotic function, has recently been identified as regulator of Tip60-dependent p53-acetylation. In an effort to clarify the role of PDCD5 upon DNA damage, we generated cell lines in which PDCD5 expression was conditionally ablated by shRNAs and investigated their response to genotoxic stress. Surprisingly, we failed to note a rate-limiting role of PDCD5 in the DNA damage response. PDCD5 was dispensable for DNA damage induced apoptosis and cell cycle arrest and we observed no significant changes in p53 target gene transcription. While we were able to confirm interaction of PDCD5 with p53, we failed to do so for Tip60. Altogether, our results suggest a role of PDCD5 in the regulation of p53 function but unrelated to cell cycle arrest or apoptosis, at least in the cell types investigated.FP06 RTN ‘ApopTrain’Tyrolean Science FundKrebshilfe-Tyro

Reutilización de aguas residuales tratadas en cultivos forrajeros y forestales en Ing. Jacobacci

El uso de aguas residuales tratadas (ART) en riego agrícola forestal es una alternativa para evitar el vuelco a cuerpos receptores hídricos, que resulta de especial interés en áreas donde el agua es escasa. Resultado de un Convenio entre el DPA, la UNR, el INTA, la Municipalidad y la Cooperativa de Aguas, se comenzó en 2015 un trabajo conjunto en la localidad de Ingeniero Jacobacci con el objetivo de diseñar y probar estrategias para el mejor uso de esas aguas residuales, con la idea que el modelo desarrollado pueda ser aplicado en otras localidades de la región. Para ello se realizaron talleres en diferentes ámbitos de la comunidad para difundir la temática y recoger percepciones y temores preexistentes acerca de la misma. Además, se instaló en febrero de 2016 un ensayo de reutilización de ART para la producción de forraje (alfalfa y campo natural) y biomasa (olivillo y sauce) en la planta de tratamiento, con el objetivo de evaluar el impacto en las propiedades del suelo y en la productividad vegetal. En la producción de forraje se observó en alfalfa un rendimiento muy superior a lo esperado en la región, no observándose diferencias significativas entre los tratamientos (promedio de 24 Ton/ha en tres cortes en el primer año y de casi 50 Ton/ha en cuatro cortes en el segundo). Por efecto del riego, en el suelo se observaron cambios en algunos parámetros edáficos como una reducción del pH en agua y un incremento en la conductividad eléctrica en las parcelas regadas con agua tratada. También se observaron incrementos en las cargas de nutrientes aunque los valores máximos observados no alcanzaron límites que impliquen riesgos ambientales. Los ensayos de especies forestales comenzarán a evaluarse en la próxima temporada. Estos resultados, si bien son preliminares y en condiciones de cultivo muy difícilmente alcanzables en una producción comercial, reflejan buenas posibilidades de producir material seca vegetal con la aplicación de agua tratada, aunque se requiere planificar un riguroso control del impacto ambiental.Estación Experimental Agropecuaria BarilocheFil: Cremona, Maria Victoria. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; ArgentinaFil: Riat, Martha. Universidad Nacional de Rio Negro; ArgentinaFil: Magnin, Santiago. Departamento Provincial de Aguas. Rio Negro; ArgentinaFil: Velasco, Virginia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Agencia de Extensión Rural Jacobacci; ArgentinaFil: Sanchez, V. Universidad Nacional de Rio Negro; ArgentinaFil: Tanzer, Laura. Departamento Provincial de Aguas. Rio Negro; Argentin

Clusters of microRNAs emerge by new hairpins in existing transcripts

Genetic linkage may result in the expression of multiple products from a polycistronic transcript, under the control of a single promoter. In animals, protein-coding polycistronic transcripts are rare. However, microRNAs are frequently clustered in the genomes of animals, and these clusters are often transcribed as a single unit. The evolution of microRNA clusters has been the subject of much speculation, and a selective advantage of clusters of functionally related microRNAs is often proposed. However, the origin of microRNA clusters has not been so far explored. Here, we study the evolution of microRNA clusters in Drosophila melanogaster. We observed that the majority of microRNA clusters arose by the de novo formation of new microRNA-like hairpins in existing microRNA transcripts. Some clusters also emerged by tandem duplication of a single microRNA. Comparative genomics show that these clusters are unlikely to split or undergo rearrangements. We did not find any instances of clusters appearing by rearrangement of pre-existing microRNA genes. We propose a model for microRNA cluster evolution in which selection over one of the microRNAs in the cluster interferes with the evolution of the other linked microRNAs. Our analysis suggests that the study of microRNAs and small RNAs must consider linkage associations

Convenio de cooperación técnica: Reutilización agrícola forestal de aguas tratadas en Ingeniero Jacobacci

El uso de aguas residuales tratadas en riego agrícola forestal es una alternativa para evitar el vuelco a cuerpos receptores hídricos, que resulta de especial interés en áreas donde la escasez de agua afecta las actividades humanas. La zona centro de la provincia de Río Negro integra los dos tercios de la superficie en la Argentina que presenta balances hídricos negativos la mayor parte del año, esto representa una importante limitación para todo tipo de actividades productivas y en muchos casos hasta se dificulta el abastecimiento de agua para consumo humano.Estación Experimental Agropecuaria BarilocheFil: Cremona, Maria Victoria. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Área de Recursos Naturales; ArgentinaFil: Velasco, Virginia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Agencia de Extensión Rural Ingeniero Jacobacci; ArgentinaFil: Zuñiga, Aldo Mario. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Área de Recursos Naturales; ArgentinaFil: Tanzer, Laura. Departamento Provincial de Aguas. Rio Negro; ArgentinaFil: Magnin, Santiago. Departamento Provincial de Aguas. Rio Negro; ArgentinaFil: Fernandez, Patricia. Departamento Provincial de Aguas. Rio Negro; ArgentinaFil: Alemanni, Maria Eugenia. Departamento Provincial de Aguas. Rio Negro; ArgentinaFil: Riat, Martha. Universidad Nacional de Rio Negro; ArgentinaFil: Laos, Francisca. Universidad Nacional de Rio Negro; ArgentinaFil: Capuano, Ana. Universidad Nacional de Rio Negro; ArgentinaFil: Güevara, Tomas. Universidad Nacional de Rio Negro; ArgentinaFil: Fornasa, Alejandro. Cooperativa de agua y otros servicios públicos de Ingeniero Jacobacci; ArgentinaFil: Mellado, José. Cooperativa de agua y otros servicios públicos de Ingeniero Jacobacci; ArgentinaFil: López, Oscar. Cooperativa de agua y otros servicios públicos de Ingeniero Jacobacci; ArgentinaFil: Currumán, Antonio. Municipalidad de Ingeniero Jacobacci; ArgentinaFil: Nasif, Abdel. Ente para el Desarrollo de la Línea y región Sur; Argentin

Metabolic synergies in the biotransformation of organic and metallic toxic compounds by a saprotrophic soil fungus

The saprotrophic fungus Penicillium griseofulvum was chosen as model organism to study responses to a mixture of hexachlorocyclohexane (HCH) isomers (α-HCH, β-HCH, γ-HCH, δ-HCH) and of potentially toxic metals (vanadium, lead) in solid and liquid media. The P. griseofulvum FBL 500 strain was isolated from polluted soil containing high concentrations of HCH isomers and potentially toxic elements (Pb, V). Experiments were performed in order to analyse the tolerance/resistance of this fungus to xenobiotics, and to shed further light on fungal potential in inorganic and organic biotransformations. The aim was to examine the ecological and bioremedial potential of this fungus verifying the presence of mechanisms that allow it to transform HCH isomers and metals under different, extreme, test conditions. To our knowledge, this work is the first to provide evidence on the biotransformation of HCH mixtures, in combination with toxic metals, by a saprotrophic non-white-rot fungus and on the metabolic synergies involved

Comparative Expression Profiling of the Chlamydia trachomatis pmp Gene Family for Clinical and Reference Strains

Chlamydia trachomatis, an obligate intracellular pathogen, is a leading worldwide cause of ocular and urogenital diseases. Advances have been made in our understanding of the nine-member polymorphic membrane protein (Pmp) gene (pmp) family of C. trachomatis. However, there is only limited information on their biologic role, especially for biological variants (biovar) and clinical strains.We evaluated expression for pmps throughout development for reference strains E/Bour and L2/434, representing different biovars, and for clinical E and L2 strains. Immunoreactivity of patient sera to recombinant (r)Pmps was also determined. All pmps were expressed at two hours. pmpA had the lowest expression but was up-regulated at 12 h for all strains, indicating involvement in reticulate body development. For pmpD, expression peaked at 36 h. Additionally, 57.7% of sera from infected and 0% from uninfected adolescents were reactive to rPmpD (p = 0.001), suggesting a role in immunogenicity. pmpF had the highest expression levels for all clinical strains and L2/434 with differential expression of the pmpFE operon for the same strains. Sera were nonreactive to rPmpF despite immunoreactivity to rMOMP and rPmpD, suggesting that PmpF is not associated with humoral immune responses. pmpFE sequences for clinical strains were identical to those of the respective reference strains. We identified the putative pmpFE promoter, which was, surprisingly, 100% conserved for all strains. Analyses of ribosomal binding sites, RNase E, and hairpin structures suggested complex regulatory mechanism(s) for this >6 Kb operon.The dissimilar expression of the same pmp for different C. trachomatis strains may explain different strain-specific needs and phenotypic distinctions. This is further supported by the differential immunoreactivity to rPmpD and rPmpF of sera from patients infected with different strains. Furthermore, clinical E strains did not correlate with the E reference strain at the gene expression level, reinforcing the need for expansive studies of clinical strains

Comparative Genomic Analysis of Human Fungal Pathogens Causing Paracoccidioidomycosis

Paracoccidioides is a fungal pathogen and the cause of paracoccidioidomycosis, a health-threatening human systemic mycosis endemic to Latin America. Infection by Paracoccidioides, a dimorphic fungus in the order Onygenales, is coupled with a thermally regulated transition from a soil-dwelling filamentous form to a yeast-like pathogenic form. To better understand the genetic basis of growth and pathogenicity in Paracoccidioides, we sequenced the genomes of two strains of Paracoccidioides brasiliensis (Pb03 and Pb18) and one strain of Paracoccidioides lutzii (Pb01). These genomes range in size from 29.1 Mb to 32.9 Mb and encode 7,610 to 8,130 genes. To enable genetic studies, we mapped 94% of the P. brasiliensis Pb18 assembly onto five chromosomes. We characterized gene family content across Onygenales and related fungi, and within Paracoccidioides we found expansions of the fungal-specific kinase family FunK1. Additionally, the Onygenales have lost many genes involved in carbohydrate metabolism and fewer genes involved in protein metabolism, resulting in a higher ratio of proteases to carbohydrate active enzymes in the Onygenales than their relatives. To determine if gene content correlated with growth on different substrates, we screened the non-pathogenic onygenale Uncinocarpus reesii, which has orthologs for 91% of Paracoccidioides metabolic genes, for growth on 190 carbon sources. U. reesii showed growth on a limited range of carbohydrates, primarily basic plant sugars and cell wall components; this suggests that Onygenales, including dimorphic fungi, can degrade cellulosic plant material in the soil. In addition, U. reesii grew on gelatin and a wide range of dipeptides and amino acids, indicating a preference for proteinaceous growth substrates over carbohydrates, which may enable these fungi to also degrade animal biomass. These capabilities for degrading plant and animal substrates suggest a duality in lifestyle that could enable pathogenic species of Onygenales to transfer from soil to animal hosts.National Institute of Allergy and Infectious Diseases (U.S.)National Institutes of Health. Department of Health and Human Services (contract HHSN266200400001C)National Institutes of Health. Department of Health and Human Services(contract HHSN2722009000018C)Brazil. National Council for Scientific and Technological Developmen

Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018.

Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell death pathways are unveiled, we propose an updated classification of cell death subroutines focusing on mechanistic and essential (as opposed to correlative and dispensable) aspects of the process. As we provide molecularly oriented definitions of terms including intrinsic apoptosis, extrinsic apoptosis, mitochondrial permeability transition (MPT)-driven necrosis, necroptosis, ferroptosis, pyroptosis, parthanatos, entotic cell death, NETotic cell death, lysosome-dependent cell death, autophagy-dependent cell death, immunogenic cell death, cellular senescence, and mitotic catastrophe, we discuss the utility of neologisms that refer to highly specialized instances of these processes. The mission of the NCCD is to provide a widely accepted nomenclature on cell death in support of the continued development of the field