Suchergebnisse

Accumulating evidence indicates that some protein-coding genes have originated de novo from previously non-coding genomic sequences. However, the processes underlying de novo gene birth are still enigmatic. In particular, the appearance of a new functional protein seems highly improbable unless there is already a pool of neutrally evolving peptides that are translated at significant levels and that can at some point acquire new functions. Here, we use deep ribosome-profiling sequencing data, together with proteomics and single nucleotide polymorphism information, to search for these peptides. We find hundreds of open reading frames that are translated and that show no evolutionary conservation or selective constraints. These data suggest that the translation of these neutrally evolving peptides may be facilitated by the chance occurrence of open reading frames with a favourable codon composition. We conclude that the pervasive translation of the transcriptome provides plenty of material for the evolution of new functional proteins. ; We are grateful for valuable discussions with many colleagues during this study. This work was funded by grants BFU2012-36820, BFU2015-65235-P and TIN2015-69175-C4-3-R from Ministerio de Economía e Innovación (Spanish Government) and co-funded by FEDER (EC). We also received funding from Agència de Gestió d'Ajuts Universitaris i de Recerca Generalitat de Catalunya (AGAUR), grant no. 2014SGR1121.

Hypocretins (also known as orexins) are hypothalamic neuropeptides involved in the regulation of sleep/wake states and feeding behavior. Recent studies have also demonstrated an important role for the hypocretin/orexin system in the addictive properties of drugs of abuse, consistent with the reciprocal innervations between hypocretin neurons and brain areas involved in reward processing. This system participates in the primary reinforcing effects of opioids, nicotine, and alcohol. Hypocretins are also involved in the neurobiological mechanisms underlying relapse to drug-seeking behavior induced by drug-related environmental stimuli and stress, as mainly described in the case of psychostimulants. Based on these preclinical studies, the use of selective ligands targeting hypocretin receptors could represent a new therapeutical strategy for the treatment of substance abuse disorders. In this review, we discuss and update the current knowledge about the participation of the hypocretin system in drug addiction and the possible neurobiological mechanisms involved in these processes regulated by hypocretin transmission. ; This work was supported by the Instituto de Salud Carlos III grants #PI07/0559,/n#PI10/00316, and #RD06/001/001 (RTA-RETICS), by the Spanish Ministry of Science/nand Technology (Consolider-C, #SAF2007-64062), the Catalan Government/n(SGR2009-00731), and by the Catalan Institution for Research and Advanced Studies/n(ICREA Academia program). A Plaza-Zabala is a recipient of a predoctoral fellowship/nfrom the Spanish Ministry of Education.

Anxiety disorders are often associated with an inability to extinguish learned fear responses. The hypocretin/orexin system is involved in the regulation of emotional states and could also participate in the consolidation and extinction of aversive memories. Using hypocretin receptor-1 and hypocretin receptor-2 antagonists, hypocretin-1 and hypocretin-2 peptides, and hypocretin receptor-1 knockout mice, we investigated the role of the hypocretin system in cue- and context-dependent fear conditioning and extinction. Hypocretins were crucial for the consolidation of fear conditioning, and this effect was mainly observed in memories with a high emotional component. Notably, after the acquisition of fear memory, hypocretin receptor-1 blockade facilitated fear extinction, whereas hypocretin-1 administration impaired this extinction process. The extinction-facilitating effects of the hypocretin receptor-1 antagonist SB334867 were associated with increased expression of cFos in the basolateral amygdala and the infralimbic cortex. Intra-amygdala, but neither intra-infralimbic prefrontal cortex nor intra-dorsohippocampal infusion of SB334867 enhanced fear extinction. These results reveal a key role for hypocretins in the extinction of aversive memories and suggest that hypocretin receptor-1 blockade could represent a novel therapeutic target for the treatment of diseases associated with inappropriate retention of fear, such as post-traumatic stress disorder and phobias. ; This work was supported by the Instituto de Salud Carlos III grants, #PI13/00042 and #RD12/0028/0023 (RTA-RETICS), by the Spanish Ministry of Science #SAF2011-29864, the/nCatalan Government (SGR2009-00731), and by the Catalan Institution for Research and Advanced Studies (ICREA Academia program). África Flores is a recipient of a predoctoral fellowship from the Spanish Ministry of Education.

La piriculariosis del arroz, causada por el hongo Magnaporthe oryzae, es la enfermedad que más pérdidas genera devastando miles de hectáreas de cultivo anualmente. Los tratamientos antifúngicos frente a esta enfermedad suelen ser de poca utilidad y se vuelven ineficaces en poco tiempo debido a la alta tasa de variación del hongo. Además, dentro del contexto legislativo actual a nivel europeo, se está restringiendo cada vez más la utilización de compuestos antifúngicos de amplio espectro debido a los posibles daños que pueden ocasionar sobre el ecosistema y la salud humana. Una alternativa prometedora al uso de los antifúngicos convencionales son los péptidos antimicrobianos, y más concretamente los péptidos dirigidos capaces de bloquear un proceso esencial para la infección del patógeno. Un paso fundamental en el proceso infectivo del hongo M. oryzae es la formación del apresorio, cuya finalidad es romper la superficie foliar y así penetrar en el mesófilo de la hoja. El desarrollo de compuestos capaces de bloquear específicamente este proceso sin afectar al ciclo vital del hongo constituiría una estrategia ventajosa en el control de la piriculariosis, a priori no tóxica para otros organismos incluido el ser humano. En este trabajo, hemos abordado este objetivo mediante dos aproximaciones, el cribado de una biblioteca combinatoria de péptidos y la modificación de secuencias de AMPs naturales mediante diseño racional. Gracias al conocimiento que se tiene sobre la secuencia y el modo de acción de los péptidos antimicrobianos, hemos diseñado una serie de péptidos capaces de controlar el desarrollo de la piriculariosis mediante inhibición específica de la formación del apresorio en M. oryzae, pero sin afectar a la viabilidad celular. Nuestros resultados indican que péptidos pequeños, como el heptapéptido PAF104, son capaces de reprimir la expresión de los genes MoMSB2 y MoMST11, implicados en la ruta de señalización de la MAPK Pmk1 imprescindible para la formación del apresorio en M. oryzae. Además, demostramos un ...

The lipid components of pathogen cell membranes have been considered as a poor pharmacological target, due to their universal distribution and apparent homogeneity throughout living organisms. Among the rare exceptions to this view one could mention polyene antibiotics such as amphotericin, or peptide antibiotics such as the polymyxins and the gramicidins. In the last two decades, however, the above notion has been challenged by two main lines of discovery; first, natural antimicrobial peptides (AMPs) that kill pathogens by interaction with phospholipids and membrane permeabilization, and secondly, cell-penetrating peptides (CPPs), capable of introducing into cells a variety of cargoes in the absence of specific receptors, again by interaction at some point with membrane phospholipids. For both AMPs and CPPs, the pharmacological proof-of-concept has been successfully demonstrated, and promising applications as nanobiotechnological tools have been envisaged though not hitherto materialized in clinical settings. In this review we briefly examine the pros and cons of these two classes of therapeutic agents, as well as strategies aimed at rationalizing and expanding their potentiality ; Work supported by the European Union (HEALTH-2007-223414, Leishdrug, to L.R. and D.A.), the Fondo de Investigaciones Sanitarias (PI061125, PS09/01928 and RETICS-FEDER RD 06/0021/0006 to L.R.), the regional governments of Madrid (S-BIO-0260/2006 to L.R) and Catalonia (2009 SGR 492 to D.A.), and the Spanish Ministry of Science and Innovation (PET2006-0139 to L.R. and D.A.).

The hybrid peptide BP178 (KKLFKKILKYLAGPAGIGKFLHSAKKDEL-OH), derived from BP100 (KKLFKKILKYL) and magainin (1-10), and engineered for plant expression, had a strong bactericidal activity but not fungicidal. Moreover, the preventive spray of tomato plants with BP178 controlled infections by the plant pathogenic bacteria Pseudomonas syringae pv. tomato and Xanthomonas campestris pv. vesicatoria, as well as the fungus Botrytis cinerea. The treatment of tomato plants with BP178 induced the expression of several genes according to microarray and RT-qPCR analysis. Upregulated genes coded for several pathogenesis-related proteins, including PR1, PR2, PR3, PR4, PR5, PR6, PR7, PR9, PR10, and PR14, as well as transcription factors like ethylene transcription factors, WRKY, NAC and MYB, involved in the salicylic acid, jasmonic acid, and ethylene-signaling pathways. BP178 induced a similar gene expression pattern to flg15 according to RT-qPCR analysis, whereas the parent peptide BP100 did not trigger such as a strong plant defense response. It was concluded that BP178 was a bifunctional peptide protecting the plant against pathogen infection through a dual mechanism of action consisting of antimicrobial activity against bacterial pathogens and plant defense elicitation on plant host ; We thank the Government of the Generalitat de Catalunya (Xarxa de Referencia en Biotecnología, and Xarxa de Referència en Tecnologia dels Aliments, SGR09626, 2008SGR812, and 2014SGR697) for support. The research group is accredited by SGR 2014-697 and TECNIO net from Catalonia. We also thank the University of Girona for a grant for research improvement 2015–2018

Background: Fire blight is an important disease affecting rosaceous plants. The causal agent is the bacteria Erwinia amylovora which is poorly controlled with the use of conventional bactericides and biopesticides. Antimicrobial peptides (AMPs) have been proposed as a new compounds suitable for plant disease control. BP100, a synthetic linear undecapeptide (KKLFKKILKYL-NH2), has been reported to be effective against E. amylovora infections. Moreover, BP100 showed bacteriolytic activity, moderate susceptibility to protease degradation and low toxicity. However, the peptide concentration required for an effective control of infections in planta is too high due to some inactivation by tissue components. This is a limitation beause of the high cost of synthesis of this compound. We expected that the combination of BP100 with lysozyme may produce a synergistic effect, enhancing its activity and reducing the effective concentration needed for fire blight control. Results: The combination of a synhetic multifunctional undecapeptide (BP100) with lysozyme produces a synergistic effect. We showed a significant increase of the antimicrobial activity against E. amylovora that was associated to the increase of cell membrane damage and to the reduction of cell metabolism. Combination of BP100 with lysozyme reduced the time required to achieve cell death and the minimal inhibitory concentration (MIC), and increased the activity of BP100 in the presence of leaf extracts even when the peptide was applied at low doses. The results obtained in vitro were confirmed in leaf infection bioassays. Conclusions: The combination of BP100 with lysozyme showed synergism on the bactericidal activity against E. amylovora and provide the basis for developing better formulations of antibacterial peptides for plant protection ; This work has been supported by the project AGL2009-13255-C02-01/AGR from MICINN of Spain. The research group has been supported in part by CIRIT of the Catalonian Government (Ref. 2009SGR812) and by the University of Girona

Background: Fire blight is an important disease affecting rosaceous plants. The causal agent is the bacteria Erwinia amylovora which is poorly controlled with the use of conventional bactericides and biopesticides. Antimicrobial peptides (AMPs) have been proposed as a new compounds suitable for plant disease control. BP100, a synthetic linear undecapeptide (KKLFKKILKYL-NH2), has been reported to be effective against E. amylovora infections. Moreover, BP100 showed bacteriolytic activity, moderate susceptibility to protease degradation and low toxicity. However, the peptide concentration required for an effective control of infections in planta is too high due to some inactivation by tissue components. This is a limitation beause of the high cost of synthesis of this compound. We expected that the combination of BP100 with lysozyme may produce a synergistic effect, enhancing its activity and reducing the effective concentration needed for fire blight control. Results: The combination of a synhetic multifunctional undecapeptide (BP100) with lysozyme produces a synergistic effect. We showed a significant increase of the antimicrobial activity against E. amylovora that was associated to the increase of cell membrane damage and to the reduction of cell metabolism. Combination of BP100 with lysozyme reduced the time required to achieve cell death and the minimal inhibitory concentration (MIC), and increased the activity of BP100 in the presence of leaf extracts even when the peptide was applied at low doses. The results obtained in vitro were confirmed in leaf infection bioassays. Conclusions: The combination of BP100 with lysozyme showed synergism on the bactericidal activity against E. amylovora and provide the basis for developing better formulations of antibacterial peptides for plant protection ; This work has been supported by the project AGL2009-13255-C02-01/AGR from MICINN of Spain. The research group has been supported in part by CIRIT of the Catalonian Government (Ref. 2009SGR812) and by the University of Girona

Background: Fire blight is an important disease affecting rosaceous plants. The causal agent is the bacteria Erwinia amylovora which is poorly controlled with the use of conventional bactericides and biopesticides. Antimicrobial peptides (AMPs) have been proposed as a new compounds suitable for plant disease control. BP100, a synthetic linear undecapeptide (KKLFKKILKYL-NH2), has been reported to be effective against E. amylovora infections. Moreover, BP100 showed bacteriolytic activity, moderate susceptibility to protease degradation and low toxicity. However, the peptide concentration required for an effective control of infections in planta is too high due to some inactivation by tissue components. This is a limitation beause of the high cost of synthesis of this compound. We expected that the combination of BP100 with lysozyme may produce a synergistic effect, enhancing its activity and reducing the effective concentration needed for fire blight control. Results: The combination of a synhetic multifunctional undecapeptide (BP100) with lysozyme produces a synergistic effect. We showed a significant increase of the antimicrobial activity against E. amylovora that was associated to the increase of cell membrane damage and to the reduction of cell metabolism. Combination of BP100 with lysozyme reduced the time required to achieve cell death and the minimal inhibitory concentration (MIC), and increased the activity of BP100 in the presence of leaf extracts even when the peptide was applied at low doses. The results obtained in vitro were confirmed in leaf infection bioassays. Conclusions: The combination of BP100 with lysozyme showed synergism on the bactericidal activity against E. amylovora and provide the basis for developing better formulations of antibacterial peptides for plant protection ; This work has been supported by the project AGL2009-13255-C02-01/AGR from MICINN of Spain. The research group has been supported in part by CIRIT of the Catalonian Government (Ref. 2009SGR812) and by the University of ...

INTRODUCTION: The recent dramatic increase in the incidence of antimicrobial resistance has been recognized by organizations such as the United Nations and World Health Organization as well as the governments of the USA and several European countries. A relatively new weapon in the fight against severe infections caused by multi-drug resistant bacteria is antimicrobial peptides (AMPs). These include colistin, currently regarded as the last line of antimicrobial therapy against multi-drug resistant microorganisms. Areas covered: Here, the authors provide an overview of the current research on AMPs. The focus is AMPs currently being developed for the treatment of recalcitrant bacterial infections, the synergies of AMPs and antibiotics, and the activity of AMPs against biofilm. This review also includes a brief introduction into the use of AMPs in infections caused by Mycobacterium, fungi, and parasites. Expert opinion: In research into new antimicrobials, AMPs are gaining increasing attention. While many are natural and are produced by a wide variety of organisms, others are being newly designed and chemically synthesized in the laboratory to achieve novel antimicrobial agents. The same strategy to fight infections in nature is thus being effectively exploited to safeguard human and animal health.

The antibacterial activity against bacterial plant pathogens and its relationships with the presence of the cyclic lipopeptide (cLP) biosynthetic genes ituC (iturin), bmyB (bacillomycin), fenD (fengycin) and srfAA (surfactin), and their corresponding antimicrobial peptide products have been studied in a collection of 64 strains of Bacillus spp. isolated from plant environments. The most frequent antimicrobial peptide (AMP) genes were bmyB, srfAAand fenD (34-50% of isolates). Most isolates (98.4%) produced surfactin isoforms, 90.6%iturins and 79.7% fengycins. The antibacterial activity was very frequent and generally intense among the collection of strains because 75% of the isolates were active against at least 6 of the 8 bacterial plant pathogens tested. Hierarchical and correspondence analysis confirmed the presence of two clearly differentiated groups. One group consisted of Bacillus strains that showed a strong antibacterial activity, presented several cLPs genes and produced several isoforms of cLPs simultaneously, mainly composed of B. subtilisand B. amyloliquefaciens, although the last one was exclusive to this group. Another group was characterized by strains with very low or none antibacterial activity, that showed one or none of the cLP genes and produced a few or none of the corresponding cLPs, and was the most heterogenous group including B. subtilis, B. licheniformis, B. megaterium, B. pumilus, B. cereusand B. thuringiensis, although the last two were exclusive to this group. This work demonstrated that the antagonistic capacity of plant-associated Bacillusagainst plant pathogenic bacteria is related to the presence of cLP genes and to the production of the corresponding cLPs, and it is mainly associated to the species B. subtilisand B. amyloliquefaciens. Our findings would help to increase the yield and efficiency of screening methods to obtain candidate strains to biocontrol agents with a mechanism of action relaying on the production of antimicrobial cLPs ; Funding was provided by Programa Nacional de Agricultura y Alimentación (CICYT) (Ref. AGL-2009-13255-C02-01) of the MINECO of Spain, and FP7 KBBE.2013.1.2-04. Ref. 613678. DROPSA project of the European Union. The research group is accredited and supported in part by SGR 2009-0812, 2014 SGR 697 and TECNIO net from Catalonia

The antibacterial activity against bacterial plant pathogens and its relationships with the presence of the cyclic lipopeptide (cLP) biosynthetic genes ituC (iturin), bmyB (bacillomycin), fenD (fengycin) and srfAA (surfactin), and their corresponding antimicrobial peptide products have been studied in a collection of 64 strains of Bacillus spp. isolated from plant environments. The most frequent antimicrobial peptide (AMP) genes were bmyB, srfAAand fenD (34-50% of isolates). Most isolates (98.4%) produced surfactin isoforms, 90.6%iturins and 79.7% fengycins. The antibacterial activity was very frequent and generally intense among the collection of strains because 75% of the isolates were active against at least 6 of the 8 bacterial plant pathogens tested. Hierarchical and correspondence analysis confirmed the presence of two clearly differentiated groups. One group consisted of Bacillus strains that showed a strong antibacterial activity, presented several cLPs genes and produced several isoforms of cLPs simultaneously, mainly composed of B. subtilisand B. amyloliquefaciens, although the last one was exclusive to this group. Another group was characterized by strains with very low or none antibacterial activity, that showed one or none of the cLP genes and produced a few or none of the corresponding cLPs, and was the most heterogenous group including B. subtilis, B. licheniformis, B. megaterium, B. pumilus, B. cereusand B. thuringiensis, although the last two were exclusive to this group. This work demonstrated that the antagonistic capacity of plant-associated Bacillusagainst plant pathogenic bacteria is related to the presence of cLP genes and to the production of the corresponding cLPs, and it is mainly associated to the species B. subtilisand B. amyloliquefaciens. Our findings would help to increase the yield and efficiency of screening methods to obtain candidate strains to biocontrol agents with a mechanism of action relaying on the production of antimicrobial cLPs ; Funding was provided by Programa Nacional de Agricultura y Alimentación (CICYT) (Ref. AGL-2009-13255-C02-01) of the MINECO of Spain, and FP7 KBBE.2013.1.2-04. Ref. 613678. DROPSA project of the European Union. The research group is accredited and supported in part by SGR 2009-0812, 2014 SGR 697 and TECNIO net from Catalonia

Synthetic linear antimicrobial peptides with cationic α-helical structures, such as BP100, have potent and specific activities against economically important plant pathogenic bacteria. They are also recognized as valuable therapeutics and preservatives. However, highly active BP100 derivatives are often phytotoxic when expressed at high levels as recombinant peptides in plants. Here we demonstrate that production of recombinant phytotoxic peptides in transgenic plants is possible by strictly limiting transgene expression to certain tissues and conditions, and specifically that minimization of this expression during transformation and regeneration of transgenic plants is essential to obtain viable plant biofactories. On the basis of whole-genome transcriptomic data available online, we identified the Os.hsp82 promoter that fulfilled this requirement and was highly induced in response to heat shock. Using this strategy, we generated transgenic rice lines producing moderate yields of severely phytotoxic BP100 derivatives on exposure to high temperature. In addition, a threshold for gene expression in selected tissues and stages was experimentally established, below which the corresponding promoters should be suitable for driving the expression of recombinant phytotoxic proteins in genetically modified plants. In view of the growing transcriptomics data available, this approach is of interest to assist promoter selection for specific purposes ; This work was financially supported by the Spanish Ministerio de Economia y Competitividad (reference AGL2010-17181/AGR). The research group belongs to 2014SGR697, recognized by the Catalonian Government. N.C. and C.R. received fellowships from Generalitat de Catalunya

Synthetic linear antimicrobial peptides with cationic α-helical structures, such as BP100, have potent and specific activities against economically important plant pathogenic bacteria. They are also recognized as valuable therapeutics and preservatives. However, highly active BP100 derivatives are often phytotoxic when expressed at high levels as recombinant peptides in plants. Here we demonstrate that production of recombinant phytotoxic peptides in transgenic plants is possible by strictly limiting transgene expression to certain tissues and conditions, and specifically that minimization of this expression during transformation and regeneration of transgenic plants is essential to obtain viable plant biofactories. On the basis of whole-genome transcriptomic data available online, we identified the Os.hsp82 promoter that fulfilled this requirement and was highly induced in response to heat shock. Using this strategy, we generated transgenic rice lines producing moderate yields of severely phytotoxic BP100 derivatives on exposure to high temperature. In addition, a threshold for gene expression in selected tissues and stages was experimentally established, below which the corresponding promoters should be suitable for driving the expression of recombinant phytotoxic proteins in genetically modified plants. In view of the growing transcriptomics data available, this approach is of interest to assist promoter selection for specific purposes ; This work was financially supported by the Spanish Ministerio de Economia y Competitividad (reference AGL2010-17181/AGR). The research group belongs to 2014SGR697, recognized by the Catalonian Government. N.C. and C.R. received fellowships from Generalitat de Catalunya

Synthetic linear antimicrobial peptides with cationic α-helical structures, such as BP100, have potent and specific activities against economically important plant pathogenic bacteria. They are also recognized as valuable therapeutics and preservatives. However, highly active BP100 derivatives are often phytotoxic when expressed at high levels as recombinant peptides in plants. Here we demonstrate that production of recombinant phytotoxic peptides in transgenic plants is possible by strictly limiting transgene expression to certain tissues and conditions, and specifically that minimization of this expression during transformation and regeneration of transgenic plants is essential to obtain viable plant biofactories. On the basis of whole-genome transcriptomic data available online, we identified the Os.hsp82 promoter that fulfilled this requirement and was highly induced in response to heat shock. Using this strategy, we generated transgenic rice lines producing moderate yields of severely phytotoxic BP100 derivatives on exposure to high temperature. In addition, a threshold for gene expression in selected tissues and stages was experimentally established, below which the corresponding promoters should be suitable for driving the expression of recombinant phytotoxic proteins in genetically modified plants. In view of the growing transcriptomics data available, this approach is of interest to assist promoter selection for specific purposes ; This work was financially supported by the Spanish Ministerio de Economia y Competitividad (reference AGL2010-17181/AGR). The research group belongs to 2014SGR697, recognized by the Catalonian Government. N.C. and C.R. received fellowships from Generalitat de Catalunya