New Structural and Functional Contexts of the Dx[DN]xDG Linear Motif: Insights into Evolution of Calcium-Binding Proteins

Binding of calcium ions (Ca2+) to proteins can have profound effects on their structure and function. Common roles of calcium binding include structure stabilization and regulation of activity. It is known that diverse families – EF-hands being one of at least twelve – use a Dx[DN]xDG linear motif to bind calcium in near-identical fashion. Here, four novel structural contexts for the motif are described. Existing experimental data for one of them, a thermophilic archaeal subtilisin, demonstrate for the first time a role for Dx[DN]xDG-bound calcium in protein folding. An integrin-like embedding of the motif in the blade of a β-propeller fold – here named the calcium blade – is discovered in structures of bacterial and fungal proteins. Furthermore, sensitive database searches suggest a common origin for the calcium blade in β-propeller structures of different sizes and a pan-kingdom distribution of these proteins. Factors favouring the multiple convergent evolution of the motif appear to include its general Asp-richness, the regular spacing of the Asp residues and the fact that change of Asp into Gly and vice versa can occur though a single nucleotide change. Among the known structural contexts for the Dx[DN]xDG motif, only the calcium blade and the EF-hand are currently found intracellularly in large numbers, perhaps because the higher extracellular concentration of Ca2+ allows for easier fixing of newly evolved motifs that have acquired useful functions. The analysis presented here will inform ongoing efforts toward prediction of similar calcium-binding motifs from sequence information alone

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Balancing food risks and food benefits: the coverage of probiotics in the UK national press

The 1980s and 1990s were marked by a series of food crises, environmental disasters and the emergence of so-called 'superbugs'. At the same time, social scientists, such as Ulrich Beck, began to study the rise of a modern 'risk society'. The late 1990s and early years of this new millennium have been marked by increasing consumer interest in organic and natural foods but also in novel food products, such as probiotics or friendly bacteria which, as supplements or added to yoghurts, promise to help fight various effects of 'modernity', from stress to superbugs. Using thematic analysis and corpus linguistic tools, this article charts the rise of probiotics from 1985 to 2006 and asks: How did this rise in popularity come about? How did science and the media contribute to it? And: How were these bacteria enlisted as agents of attitudinal change? Analysing the construction of certain food benefits in the context of a heightened state of anxiety about food risk might shed light on aspects of 'risk society' that have so far been overlooked

Expression of pituitary prolactin, growth hormone and somatolactin is modified in response to different stressors (salinity, crowding and food-deprivation) in gilthead sea bream Sparus auratus.

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Detection moleculaire des bacteries lactiques productrices d'amines biogenes

Trabajo presentado en el VII Congrès International de Biotechnologie et Valorisation des Bio-Ressources, celebrado en Tabarka (Túnez), del 20 al 23 de marzo de 2019Au cours des dernières décennies, une plus grande attention est portée à la sécurité alimentaire afin de protéger la santé humaine que ce soit sur les contaminants chimiques, contaminants physiques ou contaminants d¿origine biologique. Le secteur des aliments fermentés nécessite une attention particulière en raison de la complexité de leur processus de transformation biotechnologique. La recherche de contaminants d¿origine naturelle et biologique tels que les amines biogènes est particulièrement importante, car certaines de ces molécules, notamment l¿histamine, sont dangereuses pour l¿homme si la dose ingérée est trop élevée. L¿objectif de cette étude consiste en la détéction des souches de bactéries lactiques spécifiques (Lactobacillus, Lactococcus et Enterococcus) productrices d¿amines biogènes ainsi que la recherche des gènes codant pour les enzymes impliquées dans la production de deux amines biogènes (Tyramine, Histamine) avec des amorces spécifiques de chaque amine biogène étudié par PCR ainsi qu¿une étude sur milieu de culture spécifique. Les bactéries lactiques ont notamment été identifiées à partir_de l¿ARNr16S

Cloning of the glucocorticoid receptor (GR) in gilthead seabream (Sparus aurata)

In order to determine the cortisol response after an immune challenge in the gilthead seabream (Sparus aurata), a cortisol receptor (GR) was cloned, sequenced and its expression determined after lipopolysaccharide (LPS) treatment. To clone the gilthead seabream GR (sbGR), consecutive PCR amplifications and screening of a pituitary cDNA library were performed. We obtained a clone of 4586 bp encoding a 784aa protein. Northern blot analysis from head kidney, heart and intestine revealed that the full length sbGR mRNA was approximately 6.5 Kb. A LPS treatment, used as an acute stress model, was employed to characterise the expression of sbGR and some selected genes involved in the immune response (IL-1β, TNF-α, Mx protein, cathepsin D and PPAR-γ). All genes were expressed in all tissues examined and responses were tissue and time dependent revealing differential gene expression profiles after LPS administration. Furthermore, analysis of plasma cortisol levels after LPS injection, showed an acute response to inflammatory stress with a significant increase two and six h after injection, recovering to basal levels 12 h post-stress in all LPS concentrations tested