Functional and evolutionary analysis of DXL1, a non-essential gene encoding a 1-deoxy-D-xylulose 5-phosphate synthase like protein in Arabidopsis thaliana

The synthesis of 1-deoxy-D-xylulose 5-phosphate (DXP), catalyzed by the enzyme DXP synthase (DXS), represents a key regulatory step of the 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway for isoprenoid biosynthesis. In plants DXS is encoded by small multigene families that can be classified into, at least, three specialized subfamilies. Arabidopsis thaliana contains three genes encoding proteins with similarity to DXS, including the well-known DXS1/CLA1 gene, which clusters within subfamily I. The remaining proteins, initially named DXS2 and DXS3, have not yet been characterized. Here we report the expression and functional analysis of A. thaliana DXS2. Unexpectedly, the expression of DXS2 failed to rescue Escherichia coli and A. thaliana mutants defective in DXS activity. Coherently, we found that DXS activity was negligible in vitro, being renamed as DXL1 following recent nomenclature recommendation. DXL1 is targeted to plastids as DXS1, but shows a distinct expression pattern. The phenotypic analysis of a DXL1 defective mutant revealed that the function of the encoded protein is not essential for growth and development. Evolutionary analyses indicated that DXL1 emerged from DXS1 through a recent duplication apparently specific of the Brassicaceae lineage. Divergent selective constraints would have affected a significant fraction of sites after diversification of the paralogues. Furthermore, amino acids subjected to divergent selection and likely critical for functional divergence through the acquisition of a novel, although not yet known, biochemical function, were identified. Our results provide with the first evidences of functional specialization at both the regulatory and biochemical level within the plant DXS family

Grup de Recerca en Arqueologia Protohistòrica (GRAP). Protohistoria, Historiografía y Patrimonio

Integrado inicialmente por Francisco Gracia Alonso, Gloria Munilla, David Garcia i Rubert e Isabel Moreno, el GRAP se constituyó en 1998 bajo la dirección del primero para dar continuidad a la investigación que en el campo de la protohistoria peninsular se desarrollaba en el área de Prehistoria del Departamento de Prehistoria, Historia Antigua y Arqueología de la Universidad de Barcelona, cuyo tratamiento era muy minoritario debido a la especialización en los ámbitos del paleolítico y el neolítico de los profesores e investigadores que en aquel momento la integraban. De hecho, se retomaba así una línea de trabajo y un campo de actuación que había estado marcado hasta su fallecimiento en 1988 por la figura del profesor Joan Maluquer de Motes i Nicolau. Su magisterio había definido los estudios de Protohistoria en la Universidad de Barcelona desde su llegada procedente de la de Salamanca en 1959, al dirigir entre otras las intervenciones en los yacimientos de La Ferradura (Ulldecona), Puig de Sant Andreu (Ullastret), La Pedrera (Vallfogona), Molí d'Espígol (Tornabous), L'Oriola (Amposta), La Palma (Tortosa), Mianes (Santa Bàrbara), además de los proyectos de investigación en Alto de la Cruz (Cortes, Navarra) y Cancho Roano (Zalamea de la Serena, Badajoz), continuando en gran media los trabajos que sobre la cultura ibérica habían realizado previamente, desde la misma Universidad de Barcelona, Pere Bosch Gimpera (1916-1939) y Lluís Pericot (1933-1978) en el ejercicio de sus cátedras

Selenomethionine Incorporation into Amyloid Sequences Regulates Fibrillogenesis and Toxicity

The capacity of a polypeptide chain to engage in an amyloid formation process and cause a conformational disease is contained in its sequence. Some of the sequences undergoing fibrillation contain critical methionine (Met) residues which in vivo can be synthetically substituted by selenomethionine (SeM) and alter their properties

Male-biased gastrointestinal parasitism in a nearly monomorphic mountain ungulate

Background: Pyrenean chamois (Rupicapra pyrenaica pyrenaica) is a nearly monomorphic mountain ungulate with an unbiased sex-specific overwinter adult survival. Few differences in gastrointestinal parasitism have been reported by coprology as yet. This study aims to assess diversity, prevalence, intensity of infection and aggregation of gastrointestinal nematodes in male and female adult chamois. We expect no differences in the parasite infection rates between sexes. Findings: Gastrointestinal tracts of 28 harvested Pyrenean chamois in the Catalan Pyrenees (autumn 2012 and 2013) were necropsied and sexual differences in the diversity and structure of parasite community, prevalence, intensity of infection, and richness were investigated. We found 25 helminth species belonging to 13 different genera. Conclusions: Contrary to our expectations, male chamois showed different parasite communities, higher prevalence, intensity of infection and richness than females. Such sexual differences were clear irrespective of age of individuals. Hence, male chamois must cope with a more diverse and abundant parasite community than females, without apparent biological cost. Further research will be required to confirm this hypothesis

Pasados y presente. Estudios para el profesor Ricardo García Cárcel

Ricardo García Cárcel (Requena, 1948) estudió Historia en Valencia bajo el magisterio de Joan Reglà, con quien formó parte del primer profesorado de historia moderna en la Universidad Autónoma de Barcelona. En esta universidad, desde hace prácticamente cincuenta años, ha desarrollado una extraordinaria labor docente y de investigación marcada por un sagaz instinto histórico, que le ha convertido en pionero de casi todo lo que ha estudiado: las Germanías, la historia de la Cataluña moderna, la Inquisición, las culturas del Siglo de Oro, la Leyenda Negra, Felipe II, Felipe V, Austrias y Borbones, la guerra de la Independencia, la historia cultural, los mitos de la historia de España... Muy pocos tienen su capacidad para reflexionar, ordenar, analizar, conceptualizar y proponer una visión amplia y llena de matices sobre el pasado y las interpretaciones historiográficas. A su laboriosidad inimitable se añade una dedicación sin límites en el asesoramiento de alumnos e investigadores e impulsando revistas, dosieres, seminarios o publicaciones colectivas. Una mínima correspondencia a su generosidad lo constituye este volumen a manera de ineludible agradecimiento

The "CPC clip motif" : a conserved structural signature for heparin-binding proteins

Glycosaminoglycans (GAGs) are essential molecules that regulate diverse biological processes including cell adhesion, differentiation, signaling and growth, by interaction with a wide variety of proteins. However, despite the efforts committed to understand the molecular nature of the interactions in protein-GAG complexes, the answer to this question remains elusive. In the present study the interphases of 20 heparin-binding proteins have been analyzed searching for a conserved structural pattern. We have found that a structural motif encompassing one polar and two cationic residues (which has been named the CPC clip motif) is conserved among all the proteins deposited in the PDB. The distances between the α carbons and the side chain center of gravity of the residues composing this motif are also conserved. Furthermore, this pattern can be found in other proteins suggested to bind heparin for which no structural information is available. Hence we propose that the CPC clip motif, working like a staple, is a primary contributor to the attachment of heparin and other sulfated GAGs to heparin-binding proteins

Connecting peptide physicochemical and antimicrobial properties by a rational prediction model

The increasing rate in antibiotic-resistant bacterial strains has become an imperative health issue. Thus, pharmaceutical industries have focussed their efforts to find new potent, non-toxic compounds to treat bacterial infections. Antimicrobial peptides (AMPs) are promising candidates in the fight against antibiotic-resistant pathogens due to their low toxicity, broad range of activity and unspecific mechanism of action. In this context, bioinformatics' strategies can inspire the design of new peptide leads with enhanced activity. Here, we describe an artificial neural network approach, based on the AMP's physicochemical characteristics, that is able not only to identify active peptides but also to assess its antimicrobial potency. The physicochemical properties considered are directly derived from the peptide sequence and comprise a complete set of parameters that accurately describe AMPs. Most interesting, the results obtained dovetail with a model for the AMP's mechanism of action that takes into account new concepts such as peptide aggregation. Moreover, this classification system displays high accuracy and is well correlated with the experimentally reported data. All together, these results suggest that the physicochemical properties of AMPs determine its action. In addition, we conclude that sequence derived parameters are enough to characterize antimicrobial peptides

Chipped stone tools from the Early Bronze Age settlement of Minferri (2100-1650 cal. BC) (Lleida, Spain): Raw materials, technology and activities inferred

The main objective of this work is to advance a first approximation of the economic processes in which the Early Bronze Age lithic tools were involved, as well as the relation between the flint technology and the emerging metallurgy production among these communities.This work has been possible under the i+D Research Project: Procesos sociales, tecnológicos y económicos en la explotación de recursos minerales del Priorat (Cataluña): una vision diacrónica (HAR2010-21105-C02-01) of the Ministerio de Economía y Competitividad (Spanish Goverment). Dioscorides Marín acknowledges gladly his PhD fellowship FI-DGR 2013 of the Generalitat de Catalunya (Catalan Regional Government).Peer reviewe