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1.
Cells ; 10(7)2021 07 02.
Artículo en Inglés | MEDLINE | ID: mdl-34359847

RESUMEN

Auxin plays a dual role in growth regulation and, depending on the tissue and concentration of the hormone, it can either promote or inhibit division and expansion processes in plants. Recent studies have revealed that, beyond transcriptional reprogramming, alternative auxin-controlled mechanisms regulate root growth. Here, we explored the impact of different concentrations of the synthetic auxin NAA that establish growth-promoting and -repressing conditions on the root tip proteome and phosphoproteome, generating a unique resource. From the phosphoproteome data, we pinpointed (novel) growth regulators, such as the RALF34-THE1 module. Our results, together with previously published studies, suggest that auxin, H+-ATPases, cell wall modifications and cell wall sensing receptor-like kinases are tightly embedded in a pathway regulating cell elongation. Furthermore, our study assigned a novel role to MKK2 as a regulator of primary root growth and a (potential) regulator of auxin biosynthesis and signalling, and suggests the importance of the MKK2 Thr31 phosphorylation site for growth regulation in the Arabidopsis root tip.


Asunto(s)
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Regulación de la Expresión Génica de las Plantas , Hormonas Peptídicas/genética , Fosfoproteínas/genética , Reguladores del Crecimiento de las Plantas/farmacología , Raíces de Plantas/genética , Proteínas Quinasas/genética , Receptores de Superficie Celular/genética , Arabidopsis/crecimiento & desarrollo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Regulación del Desarrollo de la Expresión Génica , Ácidos Indolacéticos/farmacología , Meristema/genética , Meristema/crecimiento & desarrollo , Meristema/metabolismo , Quinasas de Proteína Quinasa Activadas por Mitógenos/genética , Quinasas de Proteína Quinasa Activadas por Mitógenos/metabolismo , Ácidos Naftalenoacéticos/síntesis química , Ácidos Naftalenoacéticos/farmacología , Hormonas Peptídicas/metabolismo , Fosfoproteínas/clasificación , Fosfoproteínas/metabolismo , Fosforilación , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Proteínas Quinasas/metabolismo , Procesamiento Proteico-Postraduccional , Proteoma/clasificación , Proteoma/genética , Proteoma/metabolismo , ATPasas de Translocación de Protón/genética , ATPasas de Translocación de Protón/metabolismo , Receptores de Superficie Celular/metabolismo , Transducción de Señal
2.
Lancet Oncol ; 21(12): 1661-1672, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33271095

RESUMEN

BACKGROUND: Gemogenovatucel-T is an autologous tumour cell vaccine manufactured from harvested tumour tissue, which specifically reduces expression of furin and downstream TGF-ß1 and TGF-ß2. The aim of this study was to determine the safety and efficacy of gemogenovatucel-T in front-line ovarian cancer maintenance. METHODS: This randomised, double-blind, placebo-controlled, phase 2b trial involved 25 hospitals in the USA. Women aged 18 years and older with stage III/IV high-grade serous, endometrioid, or clear cell ovarian cancer in clinical complete response after a combination of surgery and five to eight cycles of chemotherapy involving carboplatin and paclitaxel, and an Eastern Cooperative Oncology Group status of 0 or 1 were eligible for inclusion in the study. Patients were randomly assigned (1:1) to gemogenovatucel-T or placebo by an independent third party interactive response system after successful screening using randomly permuted block sizes of two and four and stratified by extent of surgical cytoreduction and neoadjuvant versus adjuvant chemotherapy. Gemogenovatucel-T (1 × 107 cells per injection) or placebo was administered intradermally (one per month) for a minimum of four and up to 12 doses. Patients, investigators, and clinical staff were masked to patient allocation until after statistical analysis. The primary endpoint was recurrence-free survival, analysed in the per-protocol population. All patients who received at least one dose of gemogenovatucel-T were included in the safety analysis. The study is registered with ClinicalTrials.gov, NCT02346747. FINDINGS: Between Feb 11, 2015, and March 2, 2017, 310 patients consented to the study at 22 sites. 217 were excluded. 91 patients received gemogenovatucel-T (n=47) or placebo (n=44) and were analysed for safety and efficacy. The median follow-up from first dose of gemogenovatucel-T was 40·0 months (IQR 35·0-44·8) and from first dose of placebo was 39·8 months (35·5-44·6). Recurrence-free survival was 11·5 months (95% CI 7·5-not reached) for patients assigned to gemogenovatucel-T versus 8·4 months (7·9-15·5) for patients assigned to placebo (HR 0·69, 90% CI 0·44-1·07; one-sided p=0·078). Gemogenovatucel-T resulted in no grade 3 or 4 toxic effects. Two patients in the placebo group had five grade 3 toxic events, including arthralgia, bone pain, generalised muscle weakness, syncope, and dyspnea. Seven patients (four in the placebo group and three in the gemogenovatucel-T group) had 11 serious adverse events. No treatment-related deaths were reported in either of the groups. INTERPRETATION: Front-line use of gemogenovatucel-T immunotherapy as maintenance was well tolerated but the primary endpoint was not met. Further investigation of gemogenovatucel-T in patients stratified by BRCA mutation status is warranted. FUNDING: Gradalis.


Asunto(s)
Vacunas contra el Cáncer/administración & dosificación , Carcinoma Endometrioide/terapia , Neoplasias Ováricas/terapia , Anciano , Vacunas contra el Cáncer/efectos adversos , Carcinoma Endometrioide/inmunología , Carcinoma Endometrioide/patología , Método Doble Ciego , Femenino , Humanos , Persona de Mediana Edad , Recurrencia Local de Neoplasia , Estadificación de Neoplasias , Neoplasias Ováricas/inmunología , Neoplasias Ováricas/mortalidad , Neoplasias Ováricas/patología , Factores de Tiempo , Resultado del Tratamiento , Estados Unidos
3.
Plant Physiol Biochem ; 142: 246-253, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31374377

RESUMEN

Transcription factors such as MYB have previously been associated with the plant response to drought. In this work, studies on the function of the barley (Hordeum vulgare L.) transcription factor HvMYB1 show that gene expression is upregulated in wildtype barley roots and leaves under drought and osmotic stress. Transgenic barley plants that overexpress HvMYB1 were found to be more resistant to drought, showing enhanced relative water content and reduced water loss rate and stomatal conductance as compared to control plants. Levels of the osmolyte proline were enhanced as was expression of dehydrin HvDNH6 in the transgenic lines under drought conditions. The levels of the reactive oxygen species H2O2 were enhanced in wildtype roots and leaves by drought, but less so in the HvMYB1 overexpressing lines. Enzyme activity of the low affinity H2O2 degrading enzyme catalase (EC 1.11.1.6) was also lower in droughted HvMYB1 overexpressing lines. Gene expression of the high affinity ROS scavengers ASCORBATE PEROXIDASE and GLUTATHIONE PEROXIDASE was found to be constitutively high in the overexpressing lines, whereas CATALASE gene expression was similar to the control plants. These results suggest a role for HvMYB1 in protecting plants against drought in the vegetative plant by acting as a mediator of abscisic acid action.


Asunto(s)
Hordeum/metabolismo , Proteínas de Plantas/metabolismo , Factores de Transcripción/metabolismo , Ácido Abscísico/metabolismo , Deshidratación , Regulación de la Expresión Génica de las Plantas , Reguladores del Crecimiento de las Plantas/metabolismo , Transpiración de Plantas , Plantas Modificadas Genéticamente
4.
J Plant Physiol ; 170(15): 1353-9, 2013 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-23702246

RESUMEN

Mitogen activated protein kinase (MAP kinase) signal transduction pathways are important eukaryotic mechanisms for regulating cellular responses to stress. The objective of this work was to investigate the role of the barley MAP kinase HvMPK4 (a homologue of the Arabidopsis MAP kinase AtMPK1) in the plant response to biotic and abiotic stress. Transgenic barley plants bearing antisense or overexpression constructs for HvMPK4 were produced, and RNA blot analysis showed that HvMPK4 gene expression was much reduced in the antisense lines and approximately double in the overexpression lines. Three independent lines of each construct were tested for their response to a fungal pathogen and to salt treatment. The antisense lines were more resistant to the hemibiotrophic fungal pathogen Magnaporthe grisea, and showed enhanced levels of salicylic acid (SA) and of hydrogen peroxide following infection; HvMPK4 is thus a negative regulator of SA production post infection. The overexpression lines had constitutively higher levels of jasmonic acid and enhanced levels of ethylene following infection but were not more resistant to the pathogen. However the overexpression lines showed greater tolerance to abiotic stress, as following 2 weeks of salt treatment these lines showed less reduction in fresh and dry weight, accumulated less salt in the leaves and contained enhanced levels of the osmoprotectant amino acid, proline.


Asunto(s)
Hordeum/efectos de los fármacos , Hordeum/enzimología , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Hordeum/microbiología , Proteínas Quinasas Activadas por Mitógenos/genética
5.
Vaccine ; 31(32): 3262-7, 2013 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-23707165

RESUMEN

Enteric redmouth disease, caused by Yersinia ruckeri, may result in high mortalities in farmed salmonids. Prophylaxis has been achieved with an immersion vaccine comprised of inactivated serovar 1 biotype 1 (motile) Y. ruckeri cultures. However, there has been a growing number of enteric redmouth outbreaks in vaccinated livestock associated with serovar 1 biotype 2 (non-motile) Y. ruckeri strains which do not produce flagellin. It was the aim of this study to evaluate the protective role of flagellin in enteric redmouth vaccines. Results showed that flagellin in the inactivated whole-cell vaccine were not the main immunoprotective molecule in eliciting a protective immune response towards infection. However, use of non-adjuvanted flagellin as a sub-unit vaccine, both in the native and recombinant form, resulted in a potent non-specific protective function towards challenge with biotype 1 (flagellin-producing) and biotype 2 (flagellin-devoid) Y. ruckeri. This vaccine can also protect rainbow trout against other microbial fish pathogens, for example Aeromonas salmonicida. Thus non-adjuvanted flagellin may have potential as a non-specific vaccine for fish towards bacterial pathogens.


Asunto(s)
Vacunas Bacterianas/uso terapéutico , Enfermedades de los Peces/prevención & control , Flagelina/inmunología , Oncorhynchus mykiss/inmunología , Yersiniosis/veterinaria , Adyuvantes Inmunológicos , Aeromonas salmonicida/inmunología , Secuencia de Aminoácidos , Animales , Vacunas Bacterianas/inmunología , Protección Cruzada , Enfermedades de los Peces/inmunología , Enfermedades de los Peces/microbiología , Flagelina/administración & dosificación , Inmersión , Datos de Secuencia Molecular , Oncorhynchus mykiss/microbiología , Proteínas Recombinantes/administración & dosificación , Proteínas Recombinantes/inmunología , Vacunación/veterinaria , Vacunas de Subunidad/administración & dosificación , Vacunas de Subunidad/uso terapéutico , Yersiniosis/inmunología , Yersiniosis/prevención & control , Yersinia ruckeri/clasificación
6.
Enzyme Microb Technol ; 52(4-5): 286-95, 2013 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-23540932

RESUMEN

While applications of amine oxidases are increasing, few have been characterised and our understanding of their biological role and strategies for bacteria exploitation are limited. By altering the nitrogen source (NH4Cl, putrescine and cadaverine (diamines) and butylamine (monoamine)) and concentration, we have identified a constitutive flavin dependent oxidase (EC 1.4.3.10) within Rhodococcus opacus. The activity of this oxidase can be increased by over two orders of magnitude in the presence of aliphatic diamines. In addition, the expression of a copper dependent diamine oxidase (EC 1.4.3.22) was observed at diamine concentrations>1mM or when cells were grown with butylamine, which acts to inhibit the flavin oxidase. A Michaelis-Menten kinetic treatment of the flavin oxidase delivered a Michaelis constant (KM)=190µM and maximum rate (kcat)=21.8s(-1) for the oxidative deamination of putrescine with a lower KM (=60µM) and comparable kcat (=18.2s(-1)) for the copper oxidase. MALDI-TOF and genomic analyses have indicated a metabolic clustering of functionally related genes. From a consideration of amine oxidase specificity and sequence homology, we propose a putrescine degradation pathway within Rhodococcus that utilises oxidases in tandem with subsequent dehydrogenase and transaminase enzymes. The implications of PUT homeostasis through the action of the two oxidases are discussed with respect to stressors, evolution and application in microbe-assisted phytoremediation or bio-augmentation.


Asunto(s)
Amina Oxidasa (conteniendo Cobre)/metabolismo , Proteínas Bacterianas/metabolismo , Oxidorreductasas actuantes sobre Donantes de Grupo CH-NH/metabolismo , Putrescina/metabolismo , Rhodococcus/enzimología , Amina Oxidasa (conteniendo Cobre)/antagonistas & inhibidores , Amina Oxidasa (conteniendo Cobre)/genética , Proteínas Bacterianas/antagonistas & inhibidores , Proteínas Bacterianas/genética , Biodegradación Ambiental , Cadaverina/metabolismo , Genes Bacterianos , Homeostasis , Cinética , Familia de Multigenes , Oxidorreductasas actuantes sobre Donantes de Grupo CH-NH/antagonistas & inhibidores , Oxidorreductasas actuantes sobre Donantes de Grupo CH-NH/genética , Rhodococcus/genética , Rhodococcus/crecimiento & desarrollo , Semicarbacidas/farmacología , Especificidad por Sustrato
7.
Proteomics ; 12(22): 3374-85, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23001927

RESUMEN

Drought is a major threat to world agriculture. In order to identify proteins associated with plant drought tolerance, barley varieties bred in the UK (Golden Promise) and Iraq (Basrah) were compared. The variety Basrah showed physiological adaptations to drought when compared to Golden Promise, for example relative water content of roots and shoots after 1 week of drought was much higher for Basrah than for Golden Promise. DIGE analysis was carried out on proteins from roots and leaves under control and drought conditions. Twenty-four leaf and 45 root proteins were identified by MALDI-TOF MS. The relative expression patterns of the identified proteins fell into a number of distinct classes. The variety Basrah is characterised by constitutive expression or higher drought-induced expression levels of proteins regulating ROS production and protein folding. Photosynthetic enzymes, by contrast, were downregulated in Basrah. Enzyme assays showed a good correlation between DIGE-derived protein abundance estimates and enzyme activity in extracts. Overall, this study shows that the enhanced drought tolerance of variety Basrah is driven by an enhanced regulation of ROS under drought.


Asunto(s)
Adaptación Fisiológica/fisiología , Sequías , Hordeum/química , Proteínas de Plantas/análisis , Proteoma/análisis , Electroforesis en Gel Bidimensional , Hordeum/metabolismo , Immunoblotting , Proteínas de Plantas/química , Proteínas de Plantas/fisiología , Proteoma/química , Proteoma/fisiología , Estrés Fisiológico/fisiología
8.
Arch Gynecol Obstet ; 286(3): 717-21, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22569711

RESUMEN

PURPOSE: A primary operative complication of radical hysterectomy for cervical cancer is hemorrhage. Intraoperative autologous blood transfusion (ABT) may be beneficial in reducing the need for homologous blood transfusion. METHODS: Our institution published a prospective cohort study examining the use of ABT in cervical cancer patients undergoing radical hysterectomy in 1995. Patients who were initially consented to participate in this prospective trial using intraoperative ABT (cell saver) were evaluated with a median follow-up of 3 years. We sought to update this original report with 16-year follow-up data collected from the clinical charts, Tumor Registry, and the Social Security Death Index. RESULTS: Two groups of patients undergoing radical hysterectomy were compared: patients who received ABT, and those who did not. Of the 71 original patients, all were included in this updated review, with an average follow-up of 12.4 years for both groups. Originally, thirty-one patients received an ABT. In this group, 1 patient was lost to follow-up, and 4 (12.9 %) are deceased including 1 (3 %) with disease. In the non-autologous group, there were 7 (17.5 %) patient deaths, including 3 (7.5 %) with disease. Eighty-three percent were alive after 12 years in both groups. The ABT group had 1 patient (3 %) who developed a secondary malignancy, a colon adenocarcinoma. The non-autologous group had 2 patients (5 %) who developed a secondary malignancy; one patient developed multiple myeloma and one patient developed a verrucous cancer of the tongue. CONCLUSIONS: Autologous blood transfusion during radical hysterectomy for cervical cancer appears safe and effective.


Asunto(s)
Transfusión de Sangre Autóloga , Carcinoma/cirugía , Histerectomía , Cuidados Intraoperatorios , Neoplasias del Cuello Uterino/cirugía , Adulto , Ensayos Clínicos como Asunto , Femenino , Estudios de Seguimiento , Humanos
10.
Mar Drugs ; 8(3): 498-518, 2010 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-20411112

RESUMEN

As a result of the continuous evolution of microbial pathogens towards antibiotic-resistance, there have been demands for the development of new and effective antimicrobial compounds. Since the 1960s, the scientific literature has accumulated many publications about novel pharmaceutical compounds produced by a diverse range of marine bacteria. Indeed, marine micro-organisms continue to be a productive and successful focus for natural products research, with many newly isolated compounds possessing potentially valuable pharmacological activities. In this regard, the marine environment will undoubtedly prove to be an increasingly important source of novel antimicrobial metabolites, and selective or targeted approaches are already enabling the recovery of a significant number of antibiotic-producing micro-organisms. The aim of this review is to consider advances made in the discovery of new secondary metabolites derived from marine bacteria, and in particular those effective against the so called "superbugs", including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin resistant enterococci (VRE), which are largely responsible for the increase in numbers of hospital acquired, i.e., nosocomial, infections.


Asunto(s)
Antiinfecciosos/química , Bacterias/química , Productos Biológicos/química , Descubrimiento de Drogas , Microbiología del Agua , Antiinfecciosos/aislamiento & purificación , Productos Biológicos/aislamiento & purificación , Productos Biológicos/farmacología , Enterococcus/efectos de los fármacos , Biología Marina , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Resistencia a la Vancomicina
11.
Plant Physiol ; 148(1): 212-22, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18599650

RESUMEN

The Arabidopsis (Arabidopsis thaliana) MKK1 and MKK2 mitogen-activated protein kinase kinases have been implicated in biotic and abiotic stress responses as part of a signaling cascade including MEKK1 and MPK4. Here, the double loss-of-function mutant (mkk1/2) of MKK1 and MKK2 is shown to have marked phenotypes in development and disease resistance similar to those of the single mekk1 and mpk4 mutants. Because mkk1 or mkk2 single mutants appear wild type, basal levels of MPK4 activity are not impaired in them, and MKK1 and MKK2 are in part functionally redundant in unchallenged plants. These findings are confirmed and extended by biochemical and molecular analyses implicating the kinases in jasmonate- and salicylate-dependent defense responses, mediated in part via the MPK4 substrate MKS1. In addition, transcriptome analyses delineate overlapping and specific effects of the kinases on global gene expression patterns demonstrating both redundant and unique functions for MKK1 and MKK2.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimología , MAP Quinasa Quinasa 1/metabolismo , Sistema de Señalización de MAP Quinasas , Quinasas de Proteína Quinasa Activadas por Mitógenos/metabolismo , Enfermedades de las Plantas/inmunología , Arabidopsis/genética , Arabidopsis/inmunología , Proteínas de Arabidopsis/genética , Ciclopentanos/metabolismo , Etilenos/metabolismo , MAP Quinasa Quinasa 1/genética , Quinasa 1 de Quinasa de Quinasa MAP/metabolismo , Quinasas de Proteína Quinasa Activadas por Mitógenos/genética , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Mutagénesis Insercional , Proteínas Nucleares , Oxilipinas/metabolismo , Fosfoproteínas/metabolismo , Reguladores del Crecimiento de las Plantas/metabolismo , Ácido Salicílico/metabolismo
12.
Proc Natl Acad Sci U S A ; 104(47): 18795-800, 2007 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-18003921

RESUMEN

The MYB-related gene ASYMMETRIC LEAVES 1 (AS1) and its orthologs have an evolutionarily conserved role in specification of leaf cell identity. AS1 is expressed in leaf founder cells, where it functions as a heterodimer with the structurally unrelated AS2 proteins to repress activity of KNOTTED 1-like homeobox (KNOX) genes. AS1 therefore confines KNOX activity to the shoot apical meristem, where it promotes stem cell function through the regulation of phytohormone activities. Here, we show that loss-of-function mutations in AS1 unexpectedly convey heightened protection against necrotrophic fungi. AS1 operates as a negative regulator of inducible resistance against these pathogens by selectively binding to the promoters of genes controlled by the immune activator, jasmonic acid (JA), damping the defense response. In contrast, AS1 is a positive regulator of salicylic acid (SA)-independent extracellular defenses against bacterial pathogens. Neither the absence of AS2 nor ERECTA function, which enhances the morphological phenotype of as1, nor the conditional or constitutive expression of KNOX genes impacted disease resistance. Thus, the function of AS1 in responses to phytopathogens is independent of its AS2-associated role in development. Loss of function in the AS1 orthologs PHAN in Antirrhinum majus and NSPHAN in Nicotiana sylvestris produced pathogen-response phenotypes similar to as1 plants, and therefore the defense function of AS1 is evolutionarily conserved in plant species with a divergence time of approximately 125 million years.


Asunto(s)
Evolución Molecular , Regulación de la Expresión Génica de las Plantas , Factores de Transcripción/inmunología , Factores de Transcripción/metabolismo , Antirrhinum/genética , Antirrhinum/inmunología , Antirrhinum/metabolismo , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Arabidopsis/inmunología , Arabidopsis/metabolismo , Botrytis/patogenicidad , Mutación/genética , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/inmunología , Regiones Promotoras Genéticas/genética , Receptores de Superficie Celular/genética , Receptores de Superficie Celular/metabolismo , Nicotiana/genética , Nicotiana/inmunología , Nicotiana/metabolismo , Factores de Transcripción/genética
13.
New Phytol ; 173(4): 713-721, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17286820

RESUMEN

MAP kinases have been linked to guard cell signalling. Arabidopsis thaliana MAP Kinase 3 (MPK3) is known to be activated by abscisic acid (ABA) and hydrogen peroxide (H(2)O(2)), which also control stomatal movements. We therefore studied the possible role of MPK3 in guard cell signalling through guard cell-specific antisense inhibition of MPK3 expression. Such transgenic plants contained reduced levels of MPK3 mRNA in the guard cells and displayed partial insensitivity to ABA in inhibition of stomatal opening, but responded normally to this hormone in stomatal closure. However, ABA-induced stomatal closure was reduced compared with controls when cytoplasmic alkalinization was prevented with sodium butyrate. MPK3 antisense plants were less sensitive to exogenous H(2)O(2), both in inhibition of stomatal opening and in promotion of stomatal closure, thus MPK3 is required for the signalling of this compound. ABA-induced H(2)O(2) synthesis was normal in these plants, indicating that MPK3 probably acts in signalling downstream of H(2)O(2). These results provide clear evidence for the important role of MPK3 in the perception of ABA and H(2)O(2) in guard cells.


Asunto(s)
Ácido Abscísico/farmacología , Arabidopsis/fisiología , Peróxido de Hidrógeno/farmacología , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Epidermis de la Planta/citología , Hojas de la Planta/citología , Arabidopsis/citología , Proteínas de Arabidopsis/metabolismo , ADN sin Sentido/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/genética , Epidermis de la Planta/fisiología , Hojas de la Planta/fisiología , Plantas Modificadas Genéticamente , Transducción de Señal , Transformación Genética
14.
Plant Signal Behav ; 2(4): 271-2, 2007 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19704678

RESUMEN

Regulation of stomatal aperture is of critical importance to plants to balance gas exchange and water loss, and also to control ingress of bacterial pathogens. MAP kinase signal transduction pathways are mediators of biotic and abiotic stress, and have been indicted in the control of stomatal movements. Cell-specific antisense was used to down-regulate MPK3 gene expression in Arabidopsis guard cells, resulting in ABA insensitivity during inhibition of stomatal opening, but a normal ABA response in promotion of closure assays. This response is similar to that of the heterotrimeric G protein alpha subunit mutant gpa1, as is the imposition of ABA insensitivity during stomatal closure by butyrate treatment, suggesting that MPK3 and GPA1 are in the same ABA signal transduction pathway and adding further evidence for parallel signalling pathways during ABA-induced closure. By contrast, antisense plants were less sensitive to H(2)O(2) in both promotion of closure and inhibition of opening assays, although H(2)O(2) production in response to ABA was not affected. Regulation of stomatal aperture by PAMPs has recently been shown to be an important plant defense mechanism; since MPK3 is also activated by such pathogen elicitors, we postulate that in addition to a signalling role in guard cell movements, MPK3 is involved in the active prevention of bacterial infection through stomata.

15.
J Gen Intern Med ; 21(12): C12-5, 2006 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-16965557

RESUMEN

We describe the case of a 43-year-old woman with transient ischemic neurologic deficits and recurrent systemic and pulmonary emboli in whom infectious work-up and extensive thrombophilic evaluation were unremarkable. Transesophageal echocardiography (TEE) established the diagnosis of nonbacterial thrombotic endocarditis (NBTE). This is a rare condition often associated with hypercoagulable states or advanced malignancy such as adenocarcinomas, characterized by cardiac vegetations along valvular coaptation lines without destruction of leaflets. In our patient, we diagnosed an ovarian clear cell adenocarcinoma, a malignant disorder that has been rarely reported in association with NBTE. This case illustrates that NBTE can present as an atypical manifestation of malignancy and must be distinguished from infective endocarditis, which implies a different therapeutic strategy. When confronted with findings of NBTE without a clear etiology, an occult neoplasm must be excluded. Anticoagulant therapy is the mainstay of treatment. However, cardiac vegetations may require surgical intervention in rare instances.


Asunto(s)
Adenocarcinoma de Células Claras/complicaciones , Endocarditis/etiología , Neoplasias Ováricas/complicaciones , Embolia Pulmonar/etiología , Trombosis de la Vena/etiología , Adenocarcinoma de Células Claras/diagnóstico por imagen , Adulto , Diagnóstico Diferencial , Ecocardiografía Transesofágica , Endocarditis/diagnóstico , Endocarditis/diagnóstico por imagen , Endocarditis Bacteriana/diagnóstico , Femenino , Humanos , Neoplasias Ováricas/diagnóstico por imagen , Recurrencia , Tomografía Computarizada por Rayos X , Trombosis de la Vena/diagnóstico , Trombosis de la Vena/diagnóstico por imagen
16.
Mar Biotechnol (NY) ; 8(6): 587-92, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16794953

RESUMEN

Of 131 bacterial isolates from seaweed, a culture of Bacillus licheniformis produced a novel protein with antibacterial activity against methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, and Listeria monocytogenes. The antibacterial activity was maximal in cultures prepared in Columbia broth containing pieces of synthetic polyurethane sponge and shaken at 210 to 230 rpm. Antibacterial activity was not found in cultures grown statically or with different speeds of rotary shaking. Reduced activity was apparent in supernatants prepared from marine 2216E broth and tryptone soya broth with or without 1% (wt/vol) sodium chloride. The antibacterial compound was sensitive to proteinase K, pronase, and trypsin, but was not affected by Tween-20, -40, -60, or -80, or alpha- or beta-amylase. Activity was not adversely affected by heating up to 40 degrees C or treatment at pH 5 to 14. The bioactive compound was determined to be associated with a protein of 30.7 kDa, which had homology to the YbdN protein of B. licheniformis ATCC 14580.


Asunto(s)
Antibacterianos/farmacología , Bacillus/metabolismo , Proteínas Bacterianas/farmacología , Enterococcus/efectos de los fármacos , Listeria monocytogenes/efectos de los fármacos , Staphylococcus aureus/efectos de los fármacos , Secuencia de Aminoácidos , Antibacterianos/metabolismo , Proteínas Bacterianas/metabolismo , Resistencia a la Meticilina , Resistencia a la Vancomicina
17.
Proteomics ; 6(6): 1886-96, 2006 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-16470656

RESUMEN

14-3-3 proteins are important eukaryotic regulatory proteins. Barley (Hordeum vulgare L.) 14-3-3A was over-expressed, immobilised and used to affinity purify 14-3-3 binding proteins from developing barley grains. Binding was shown to be phosphorylation-dependent. These proteins were fractionated by PAGE and identified by MALDI-TOF MS. In total, 54 14-3-3 binding proteins were identified, 49 of these interactions are novel to plants. These proteins fell into a number of functional categories. The largest category was for carbohydrate metabolism, including plastidic enzymes for starch synthesis and modification. 14-3-3 was shown to be present in isolated plastids. Four of five enzymes involved in sucrose biosynthesis from triose phosphates were identified, suggesting co-ordinated regulation of this pathway. Invertase and sucrose synthase, which break down sucrose to hexoses, were found. Sucrose synthase activity was shown to be inhibited by exogenous 14-3-3 in a dosage-dependent manner. The second-largest functional group was for proteins involved in stress and defence responses; for example, RGH2A, closely related to the MLA powdery mildew resistance protein, was found. This work illustrates the broad range of processes in which 14-3-3 may be involved, and augments previous data demonstrating key roles in carbohydrate metabolism and plant defence.


Asunto(s)
Proteínas 14-3-3/análisis , Hordeum/química , Hordeum/crecimiento & desarrollo , Proteínas de Plantas/análisis , Proteoma/análisis , Proteómica/métodos , Western Blotting , Cromatografía de Afinidad , Cromatografía por Intercambio Iónico , Electroforesis en Gel Bidimensional , Electroforesis en Gel de Poliacrilamida , Espectrometría de Masas , Mapeo Peptídico , Proteínas de Plantas/aislamiento & purificación , Proteínas de Plantas/metabolismo , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción
18.
Microbiology (Reading) ; 151(Pt 9): 3051-3058, 2005 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16151215

RESUMEN

Inter-strain and inter-species inhibition mediated by a bacteriocin-like inhibitory substance (BLIS) from a pathogenic Vibrio harveyi strain VIB 571 was demonstrated against four isolates of the same species, and one culture each of a Vibrio sp., Vibrio fischeri, Vibrio gazogenes and Vibrio parahaemolyticus. The crude BLIS, which was obtained by ammonium-sulphate precipitation of the cell-free supernatant of a 72 h broth culture of strain VIB 571, was inactivated by lipase, proteinase K, pepsin, trypsin, pronase E, SDS and incubation at > or =60 degrees C for 10 min. The activity was stable between pH 2-11 for at least 5 h. Anion-exchange chromatography, gel filtration, SDS-PAGE and two-dimensional gel electrophoresis revealed the presence of a single major peak, comprising a protein with a pI of approximately 5.4 and a molecular mass of approximately 32 kDa. The N-terminal amino acid sequence of the protein comprised Asp-Glu-Tyr-Ile-Ser-X-Asn-Lys-X-Ser-Ser-Ala-Asp-Ile (with X representing cysteine or modified amino acid residues). A similarity search based on the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) generated peptide masses and the N-terminal sequence did not yield any significant matches.


Asunto(s)
Bacteriocinas/análisis , Vibrio/química , Bacteriocinas/química , Electroforesis en Gel de Poliacrilamida , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Vibrio/patogenicidad
19.
Plant J ; 39(4): 599-611, 2004 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-15272877

RESUMEN

The barley protein limit dextrinase inhibitor (LDI), structurally related to the alpha-amylase/trypsin inhibitor family, is an inhibitor of the starch debranching enzyme limit dextrinase (LD). In order to investigate the function of LDI, and the consequences for starch metabolism of reduced LDI activity, transgenic barley plants designed to downregulate LDI by antisense were generated. Homozygous antisense lines with reduced LDI protein level and activity were analysed and found to have enhanced free LD activity in both developing and germinating grains. In addition the antisense lines showed unpredicted pleiotropic effects on numerous enzyme activities, for example, alpha- and beta-amylases and starch synthases. Analysis of the starch showed much reduced numbers of the small B-type starch granules, as well as reduced amylose relative to amylopectin levels and reduced total starch. The chain length distribution of the amylopectin was modified with less of the longer chains (>25 units) and enhanced number of medium chains (10-15 units). These results suggest an important role for LDI and LD during starch synthesis as well as during starch breakdown.


Asunto(s)
Amilopectina/química , Regulación hacia Abajo , Glicósido Hidrolasas/antagonistas & inhibidores , Hordeum/enzimología , Almidón/química , Amilopectina/metabolismo , Cromatografía en Agarosa , ADN sin Sentido , Expresión Génica , Glicósido Hidrolasas/metabolismo , Hordeum/metabolismo , Hordeum/ultraestructura , Plantas Modificadas Genéticamente , Almidón/metabolismo
20.
J Exp Bot ; 53(366): 147-8, 2002 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11741051

RESUMEN

A barley (Hordeum vulgare L.) cDNA, PM19, encoding a putative plasma membrane protein was isolated through differential screening of a dormant wild oat embryo library. PM19 is expressed in barley embryos from mid-embryogenesis up to maturity. PM19 mRNA levels decline upon germination, whereas dormant embryos retained high levels of message for up to 72 h of imbibition. PM19 mRNA levels also remained high or were reinduced in non-dormant embryos by treatments that prevented germination (250 mm NaCl, 10% sorbitol, or 50 microm ABA). The PM19 protein sequence is highly conserved in monocotyledonous and dicotyledonous plants.


Asunto(s)
Hordeum/genética , Proteínas de la Membrana/genética , Proteínas de Plantas/genética , Secuencia de Aminoácidos , Membrana Celular/genética , Membrana Celular/metabolismo , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Germinación/efectos de los fármacos , Germinación/genética , Hordeum/metabolismo , Proteínas de la Membrana/metabolismo , Datos de Secuencia Molecular , Proteínas de Plantas/metabolismo , ARN Mensajero/efectos de los fármacos , ARN Mensajero/genética , ARN Mensajero/metabolismo , Semillas/genética , Semillas/metabolismo , Homología de Secuencia de Aminoácido , Cloruro de Sodio/farmacología , Sorbitol/farmacología
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