Environmental and anthropogenic driven transitions in the demersal ecosystem of Cantabrian Sea

In the framework of global human-induced change, marine communities’ often respond to changing conditions abruptly reorganizing into new equilibria. These shifts are difficult to predict and often imply irreversible adjustments due to hysteresis. Unraveling the role of the forces leading regime shifts is a major challenge. We explored the temporal evolution of 63 fish species representing the Cantabrian bentho-demersal community in response to environmental changes and fishing pressure in the period 1983–2018, using survey data. Via multivariate analysis and non-additive modeling of a community index and the system's main stressors, two decadal-scale regimes were revealed, suggesting a non-linear response of the community to its environment. The Integrated Resilience Assessment framework elucidated the response mechanism to the candidate stressors and allowed quantifying resilience dynamics. The decline in fishing pressure in the 1990s was associated with a gradual transition of the system, while further decline during the 2000s eroded the resilience of the system towards changes in its stressors, leading to a discontinuous response expressed as an abrupt, possibly irreversible shift in the 2010s. Given the teleconnected character of marine ecosystems, this regional study endorses the scientific effort for actions facing the dynamic impacts of climate change on exploited marine ecosystems.En prensa2,27

The importance of regional differences in vulnerability to climate change for demersal fisheries

Regional differences in climate vulnerability are particularly important in many countries with socio-ecological gradients or geographical and environmental spatial segregation. Many studies are regularly performed at the national level, but regional assessments can provide more detailed information and important insights into intra-national vulnerabilities. They require detailed information of many socio-ecological components that are often neglected at the regional scale but are meaningful and operational at national and international levels. In this work, we developed a climate vulnerability assessment (CVA) to investigate the vulnerability of demersal fisheries based on 19 indicators covering exposure, fisheries sensitivity, species sensitivity (SS) and adaptive capacity (AC) for nine coastal regions of Spain, contrasting the Mediterranean to Atlantic areas. Exposure was consistently larger in the Mediterranean than Atlantic regions, while AC showed the opposite trend. While fisheries and SS did not display a clear Atlantic-Mediterranean pattern, they were critical for capturing regional differences that have an impact on fisheries vulnerability. Our results highlight the generally higher vulnerability of Mediterranean demersal fisheries, mainly due to the lower AC and higher exposure of Mediterranean regions, while providing key regional elements for guiding national and international actions for adaptation. This study demonstrates that the spatial scale considered in the development of CVAs must recognise the spatial heterogeneity in the socio-ecological system within its unit of analysis in order to be a relevant tool for management and policy makers.Preprint2,27

Diagnostico del Impacto del Palangre de Fondo en los Hábitats Bentónicos en los LICs de la RN20000

En prens

Crystallization and preliminary X-ray diffraction analysis of the invertase from Saccharomyces cerevisiae

4 pags, 4 figsSaccharomyces cerevisiae invertase (ScInv) is an enzyme encoded by the SUC2 gene that releases β-fructose from the nonreducing termini of various β - d-fructofuranoside substrates. Its ability to produce 6-kestose by transglycosylation makes this enzyme an interesting research target for applications in industrial biotechnology. The native enzyme, which presents a high degree of oligomerization, was crystallized by vapour-diffusion methods. The crystals belonged to space group P3121, with unit-cell parameters a = 268.6, b = 268.6, c = 224.4 A. The crystals diffracted to 3.3 A resolution and gave complete data sets using a synchrotron X-ray source. © 2012. © 2012 International Union of Crystallography All rights reserved.This work was supported by grant Nos. BIO2010-20508-C04-02 and BIO2010-20508-C04-03 from Dirección General de Investigación, MICINN. This is a product of the Project ‘Factoría Española de Cristalización’ Ingenio/Consolider 2010. MAS-P is supported by a JAE-PreDoc fellowship from CSIC. We also thank the ESRF for beam time and the ID23-1 staff for providing assistance with data collection

Three-dimensional structure of Saccharomyces invertase: Role of a non-catalytic domain in oligomerization and substrate specificity

© 2013 by The American Society for Biochemistry and Molecular Biology, Inc.Invertase is an enzyme that is widely distributed among plants and microorganisms and that catalyzes the hydrolysis of the disaccharide sucrose into glucose and fructose. Despite the important physiological role of Saccharomyces invertase (SInv)and the historical relevance of this enzyme as a model in early biochemical studies, its structure had not yet been solved. We report here the crystal structure of recombinant SInv at 3.3 Aring; resolution showing that the enzyme folds into the catalytic β-propeller and β-sandwich domains characteristic of GH32 enzymes. However, SInv displays an unusual quaternary structure. Monomers associate in two different kinds of dimers, which are in turn assembled into an octamer, best described as a tetramer of dimers. Dimerization plays a determinant role in substrate specificity because this assembly sets steric constraints that limit the access to the active site of oligosaccharides of more than four units. Comparative analysis of GH32 enzymes showed that formation of the SInv octamer occurs through a β-sheet extension that seems unique to this enzyme. Interaction between dimers is determined by a short amino acid sequence at the beginning of the β-sandwich domain. Our results highlight the role of the non-catalytic domain in fine-tuning substrate specificity and thus supplement our knowledge of the activity of this important family of enzymes. In turn, this gives a deeper insight into the structural features that rule modularity and protein-carbohydrate recognition.This work was supported in part by Grants BIO2010-20508-C04-02 and BIO2010-20508-C04-03 from the Spanish Ministry of Education and Science.Peer Reviewe