Serina 284 como regulador de la dimerización y de la localización celular de ERK2

ABSTRACT: Signals conveyed through ERK1/2 Mitogen-Activated Protein Kinases are well-known to play a critical role in cancer initiation, progression, and therapy resistance. It has been demonstrated that the balance between ERK monomers and dimers and cytoplasmic and nuclear sub-signals are critical for the biological outcomes resulting from ERK activation subcellular distribution. Studying the efficacy of DEL22379, a new compound that blocks ERK dimerization, we made the startling observation that ERK dimerization was restricted to mammalians. A comparison of the ERK2 sequence through the evolutionary scale unveiled that Serine284 (H.sapiens) was conserved in those species in which ERK2 dimerized, being suggestive of playing some role in ERK2 dimerization. Indeed, we have shown that Ser284 is necessary but not sufficient for ERK2 dimerization. Moreover, Ser284 is a phosphorylatable residue of ERK2, being a cytoplasmic marker of active ERK2. This phosphorylation, mediated by MEK1 and AKT1, enhances ERK affinity for the scaffold KSR1 and reduces ERK2 interaction with nuclear shuttles like IMP7; being critical for the regulation of ERK2 subcellular distribution. In addition, the sensitivity to BRAF mutant melanoma cells to vemurafenib treatment correlates with higher levels of phospho-Ser284. Thus, p-Ser284 levels could be used as a predictive biomarker for the response to vemurafenib in BRAF positive melanoma patients.RESUMEN: La señalización a través de la ruta de las MAP kinasas ERK1/2 está claramente implicada en el desarrollo y progresión tumoral, así como en la aparición de resistencias. Se ha demostrado que el equilibrio entre los monómeros y los dímeros de ERK y su señalización citoplasmática y nuclear son críticas para los efectos biológicos debidos a su activación en función de su distribución subcelular. Estudiando los efectos de DEL22379, un inhibidor de la dimerización de ERK, hicimos el sorprendente descubrimiento de que ERK2 dimeriza solo en mamíferos. A través de la comparación de la secuencia de ERK en distintas especies observamos que el residuo Ser284 (en humano) estaba conservado en aquellas especies donde ERK dimeriza, lo que sugiere que podría jugar un papel importante en la dimerización de ERK2. En efecto, hemos demostrado que la fosforilación de la Ser284 es necesaria pero no suficiente para la dimerización de ERK2. Dicha fosforilación, que es mediada por MEK1 y AKT1, aumenta la afinidad de ERK2 por el scaffold KSR1 y reduce la afinidad por proteínas transportadoras nucleares como la IMP7; siendo crítica para la regulación de la distribución subcelular de ERK2. Además, aquellas células tumorales de melanoma portadoras de la mutación en BRAF, sensibles al tratamiento con Vemurafenib, muestran una mayor fosforilación en Ser284. Por tanto, los niveles de p-Ser284 podrían servir como biomarcador predictivo de respuesta al tratamiento con Vemurafenib en pacientes con melanoma.La presente Tesis Doctoral titulada “Serine 284 as a regulator of ERK2 dimerization and cellular localization” ha sido realizada en el Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC) en el laboratorio de Regulación espacial de las señales RAS/ERK en cáncer gracias a la Ayuda para contratos predoctorales para la formación de doctores de la agencia estatal consejo superior de investigaciones científicas (BES-2016-077555) y a los proyectos financiados por: MINECO, Ciberonc Isciii, AECC. Durante el presente trabajo Vincenzo Cappitelli ha realizado una estancia predoctoral de 3 meses y medio en el laboratorio del Dr. Adam Hurlstone en la Faculty of Biology, Medicine and Health de la Universidad de Manchester, Reino Unido, gracias a la ayuda para la realización de estancias en otros centros de i+d del ministerio de economía, industria y competitividad (BES-2016-077555)

The Ecology of Subaerial Biofilms in Dry and Inhospitable Terrestrial Environments

The ecological relationship between minerals and microorganisms arguably represents one of the most important associations in dry terrestrial environments, since it strongly influences major biochemical cycles and regulates the productivity and stability of the Earth's food webs. Despite being inhospitable ecosystems, mineral substrata exposed to air harbor form complex and self-sustaining communities called subaerial biofilms (SABs). Using life on air-exposed minerals as a model and taking inspiration from the mechanisms of some microorganisms that have adapted to inhospitable conditions, we illustrate the ecology of SABs inhabiting natural and built environments. Finally, we advocate the need for the convergence between the experimental and theoretical approaches that might be used to characterize and simulate the development of SABs on mineral substrates and SABs' broader impacts on the dry terrestrial environment

Recent progress in bio-inspired biofilm-resistant polymeric surfaces

Any surface of human interest can serve as a substrate for biofilm growth, sometimes with detrimental effects. The social and economic consequences of biofilm-mediated damage to surfaces are significant, the financial impact being estimated to be billions of dollars every year. After describing traditional biocide-based approaches for the remediation of biofilm-affected surfaces, this review deals with more recent developments in material science, focusing on non-toxic, eco-sustainable nature-inspired biomaterials with anti-biofilm properties superior to the conventional biocide-based approaches in terms of addressing the biofilm problem

Zosteric acid and salicylic acid bound to a low density polyethylene surface successfully control bacterial biofilm formation

The active moieties of the anti-biofilm natural compounds zosteric (ZA) and salicylic (SA) acids have been covalently immobilized on a low density polyethylene (LDPE) surface. The grafting procedure provided new non-toxic eco-friendly materials (LDPE-CA and LDPE-SA) with anti-biofilm properties superior to the conventional biocide-based approaches and with features suitable for applications in challenging fields where the use of antimicrobial agents is limited. Microbiological investigation proved that LDPE-CA and LDPE-SA: (1) reduced Escherichia coli biofilm biomass by up to 61% with a mechanism that did not affect bacterial viability; (2) significantly affected biofilm morphology, decreasing biofilm thickness, roughness, substratum coverage, cell and matrix polysaccharide bio-volumes by >80% and increasing the surface to bio-volume ratio; (3) made the biofilm more susceptible to ampicillin and ethanol. Since no molecules were leached from the surface, they remained constantly effective and below the lethal level; therefore, the risk of inducing resistance was minimized

Biocleaning of nitrate alterations on wall paintings by Pseudomonas stutzeri

Microorganisms have been considered as causative agents of biodeterioration in multiple artworks. In this paper, we argue that microorganisms can be positively used for the cleaning of salt crusts otherwise difficult to remove by traditional restoration methods. We use Pseudomonas stutzeri to efficiently clean wall paintings. The bacteria allow for adequate and homogenous removal of insoluble salt efflorescence without damaging the painted layer. We also make use of a new application support consisting of agar. This new technology has been successfully applied in the biocleaning of eighteen-century murals located in a lunette of the Santos Juanes church in Valencia, Spain.This work has appreciated partial financial support from the Universitat Politecnica de Valencia (PAID-05-09: Biotecnologia microbiana aplicada a la limpieza y restauracion de superficies de obras de arte), coordination by Rosa Maria Montes Estelles, and support from the Spanish Ministerio de Ciencia e Innovacion, with a Ph.D. scholarship for Pilar Bosch Roig (BES-2006-12110). The authors wish to thank to the priest of the Santos Juanes Church of Valencia; the 'Direccion General de Patrimonio'; Professor Pilar Roig Picazo; Gianluigi Colalucci, Donatella Zari and Carlo Giantomassi restorers of the Campo Santo di Pisa; Jose Juan Baldo and Irene Carpio, restorers of the Santos Juanes church of Valencia; to Mathieu Viau-Courville; the Instituto Universitario de Restauracion del Patrimonio; and Restaura BioTech S.L.; and particularly to Giancarlo Ranalli due to his invaluable help for the development of this manuscript.Bosch Roig, MDP.; Regidor Ros, JL.; Montes Estellés, RM. (2013). Biocleaning of nitrate alterations on wall paintings by Pseudomonas stutzeri. International Biodeterioration and Biodegradation. 84:266-274. https://doi.org/10.1016/j.ibiod.2012.09.009S2662748

Testing Anti-Biofilm Polymeric Surfaces : Where to Start?

Present day awareness of biofilm colonization on polymeric surfaces has prompted the scientific community to develop an ever-increasing number of new materials with anti-biofilm features. However, compared to the large amount of work put into discovering potent biofilm inhibitors, only a small number of papers deal with their validation, a critical step in the translation of research into practical applications. This is due to the lack of standardized testing methods and/or of well-controlled in vivo studies that show biofilm prevention on polymeric surfaces; furthermore, there has been little correlation with the reduced incidence of material deterioration. Here an overview of the most common methods for studying biofilms and for testing the anti-biofilm properties of new surfaces is provided

Promoting beneficial and inhibiting undesirable biofilm formation with mangrove extracts

The extracts of two mangrove species, Bruguiera cylindrica and Laguncularia racemosa, have been analyzed at sub-lethal concentrations for their potential to modulate biofilm cycles (i.e., adhesion, maturation, and detachment) on a bacterium, yeast, and filamentous fungus. Methanolic leaf extracts were also characterized, and MS/MS analysis has been used to identify the major compounds. In this study, we showed the following. (i) Adhesion was reduced up to 85.4% in all the models except for E. coli, where adhesion was promoted up to 5.10-fold. (ii) Both the sum and ratio of extracellular polysaccharides and proteins in mature biofilm were increased up to 2.5-fold and 2.6-fold in comparison to the negative control, respectively. Additionally, a shift toward a major production of exopolysaccharides was found coupled with a major production of both intracellular and extracellular reactive oxygen species. (iii) Lastly, detachment was generally promoted. In general, the L. racemosa extract had a higher bioactivity at lower concentrations than the B. cylindrica extract. Overall, our data showed a reduction in cells/conidia adhesion under B. cylindrica and L. racemosa exposure, followed by an increase of exopolysaccharides during biofilm maturation and a variable effect on biofilm dispersal. In conclusion, extracts either inhibited or enhanced biofilm development, and this effect depended on both the microbial taxon and biofilm formation step

Aesthetic Alteration of Marble Surfaces Caused by Biofilm Formation: Effects of Chemical Cleaning

Despite the massive presence of biofilms causing aesthetic alteration to the facade of the Monza Cathedral, our team in a previous work proved that the biocolonization was not a primary damaging factor if compared to chemical-physical deterioration due to the impact of air pollution. Nonetheless, the conservators tried to remove the sessile dwelling microorganisms to reduce discolouration. In this research, two nearby sculpted leaves made of Candoglia marble were selected to study the effects of a chemical treatment combining the biocides benzalkonium chloride, hydrogen peroxide and Algophase\uae and mechanical cleaning procedures. One leaf was cleaned with the biocides and mechanically, and the other was left untreated as control. The impact of the treatment was investigated after 1 month from the cleaning by digital microscopy, environmental scanning electron microscopy, confocal microscopy and molecular methods to determine the composition and the functional profiles of the bacterial communities. Despite the acceptable aesthetic results obtained, the overall cleaning treatment was only partially effective in removing the biofilm from the colonized surfaces and, therefore, not adequately suitable for the specific substrate. Furthermore, the cleaning process selected microorganisms potentially more resistant to biocides so that the efficacy of future re-treatment by antimicrobial agents could be negatively affected

Biofilm formation in food processing environments is still poorly understood and controlled

The presence of undesirable biofilms on food processing contact surfaces may lead to: 1) transmission of diseases; 2) food spoilage; 3) shortened time between cleaning events; 4) contamination of product by nonstarter bacteria; 5) metal corrosion in pipelines and tanks; 6) reduced heat transfer efficacy or even obstruction of the heat equipment. Despite the significant problems caused by biofilms in the food industry, biofilm formation in these environments is still poorly understood and effective control of biofilms remains challenging. Although it is understood that cell attachment and biofilm formation are influenced by several factors, including type of strain, chemical-physical properties of the surface, temperature, growth media, and the presence of other microorganisms, some conflicting statements can be retrieved from the literature and there are no general trends yet that allow us to easily predict biofilm development. It is likely that still unexplored nteraction of factors may be more critical than the effect of a single parameter. New alternative biofilm control strategies, such as biocontrol, use of enzymes and phages, and cell-to-cell communication interference, are now available that can reduce the use of chemical agents. In addition, as preventing biofilm formation is a more efficient strategy than controlling mature biofilm, the use of surface-modified materials have been suggested. These strategies may better reveal their beneficial potential when the ecological complexity of biofilms in food environments is addressed