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1.
bioRxiv ; 2024 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-38370821

RESUMEN

Although genome-wide association studies (GWAS) have identified loci associated with alcohol consumption and alcohol use disorder (AUD), they do not identify which variants are functional. To approach this, we evaluated the impact of variants in 3' untranslated regions (3'-UTRs) of genes in loci associated with substance use and neurological disorders using a massively parallel reporter assay (MPRA) in neuroblastoma and microglia cells. Functionally impactful variants explained a higher proportion of heritability of alcohol traits than non-functional variants. We identified genes whose 3'UTR activities are associated with AUD and alcohol consumption by combining variant effects from MPRA with GWAS results. We examined their effects by evaluating gene expression after CRISPR inhibition of neuronal cells and stratifying brain tissue samples by MPRA-derived 3'-UTR activity. A pathway analysis of differentially expressed genes identified inflammation response pathways. These analyses suggest that variation in response to inflammation contributes to the propensity to increase alcohol consumption.

2.
Genes (Basel) ; 14(10)2023 09 26.
Artículo en Inglés | MEDLINE | ID: mdl-37895219

RESUMEN

Mesenchymal stem cells (MSC) are multipotent stem cells that can differentiate into multiple cell types, including osteoblasts, chondrocytes, and adipocytes. Osteoblast differentiation is reduced during osteoporosis development, resulting in reduced bone formation. Further, MSC isolated from different donors possess distinct osteogenic capacity. In this study, we used single-cell multiomic analysis to profile the transcriptome and epigenome of MSC from four healthy donors. Data were obtained from ~1300 to 1600 cells for each donor. These cells were clustered into four groups, indicating that MSC from different donors have distinct chromatin accessible regulatory elements for regulating gene expression. To investigate the mechanism by which MSC undergo osteogenic differentiation, we used the chromatin accessibility data from the single-cell multiome data to identify individual-specific enhancer-promoter pairs and evaluated the expression levels and activities of the transcriptional regulators. The MSC from four donors showed distinct differentiation potential into osteoblasts. MSC of donor 1 showed the largest average motif activities, indicating that MSC from donor 1 was most likely to differentiate into osteoblasts. The results of our validation experiments were consistent with the bioinformatics prediction. We also tested the enrichment of genome-wide association study (GWAS) signals of several musculoskeletal disease traits in the patient-specific chromatin accessible regions identified in the single-cell multiome data, including osteoporosis, osteopenia, and osteoarthritis. We found that osteoarthritis-associated variants were only enriched in the regions identified from donor 4. In contrast, osteoporosis and osteopenia variants were enriched in regions from donor 1 and least enriched in donor 4. Since osteoporosis and osteopenia are related to the density of bone cells, the enrichment of variants from these traits should be correlated with the osteogenic potential of MSC. In summary, this study provides large-scale data to link regulatory elements with their target genes to study the regulatory relationships during the differentiation of mesenchymal stem cells and provide a deeper insight into the gene regulatory mechanism.


Asunto(s)
Enfermedades Óseas Metabólicas , Células Madre Mesenquimatosas , Osteoartritis , Osteoporosis , Humanos , Osteogénesis/genética , Multiómica , Estudio de Asociación del Genoma Completo , Diferenciación Celular/genética , Células Madre Mesenquimatosas/metabolismo , Osteoporosis/genética , Enfermedades Óseas Metabólicas/metabolismo , Osteoartritis/metabolismo , Cromatina/metabolismo
3.
Curr Biol ; 31(23): 5377-5384.e5, 2021 12 06.
Artículo en Inglés | MEDLINE | ID: mdl-34666004

RESUMEN

Transcription initiation has long been considered a primary regulatory step in gene expression. Recent work, however, shows that downstream events, such as transcription elongation, can also play important roles.1-3 A well-characterized example from animals is promoter-proximal pausing, where transcriptionally engaged Pol II accumulates 30-50 bp downstream of the transcription start site (TSS) and is thought to enable rapid gene activation.2 Plants do not make widespread use of promoter-proximal pausing; however, in a phenomenon known as 3' pausing, a significant increase in Pol II is observed near the transcript end site (TES) of many genes.4-6 Previous work has shown that 3' pausing is promoted by the BORDER (BDR) family of negative transcription elongation factors. Here we show that BDR proteins play key roles in gene repression. Consistent with BDR proteins acting to slow or pause elongating Pol II, BDR-repressed genes are characterized by high levels of Pol II occupancy, yet low levels of mRNA. The BDR proteins physically interact with FPA,7 one of approximately two dozen genes collectively referred to as the autonomous floral-promotion pathway,8 which are necessary for the repression of the flowering time gene FLOWERING LOCUS C (FLC).9-11 In early-flowering strains, FLC expression is repressed by repressive histone modifications, such as histone H3 lysine 27 trimethylation (H3K27me3), thereby allowing the plants to flower early. These results suggest that the repression of transcription elongation by BDR proteins may allow for the temporary pausing of transcription or facilitate the long-term repression of genes by repressive histone modifications.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Animales , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Flores/genética , Flores/metabolismo , Histonas/metabolismo , ARN Polimerasa II/genética , ARN Polimerasa II/metabolismo , Transcripción Genética
4.
Elife ; 102021 04 27.
Artículo en Inglés | MEDLINE | ID: mdl-33904405

RESUMEN

Genes involved in disease resistance are some of the fastest evolving and most diverse components of genomes. Large numbers of nucleotide-binding, leucine-rich repeat (NLR) genes are found in plant genomes and are required for disease resistance. However, NLRs can trigger autoimmunity, disrupt beneficial microbiota or reduce fitness. It is therefore crucial to understand how NLRs are controlled. Here, we show that the RNA-binding protein FPA mediates widespread premature cleavage and polyadenylation of NLR transcripts, thereby controlling their functional expression and impacting immunity. Using long-read Nanopore direct RNA sequencing, we resolved the complexity of NLR transcript processing and gene annotation. Our results uncover a co-transcriptional layer of NLR control with implications for understanding the regulatory and evolutionary dynamics of NLRs in the immune responses of plants.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Proteínas NLR/metabolismo , Proteínas de Unión al ARN/metabolismo , Terminación de la Transcripción Genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Regulación de la Expresión Génica de las Plantas , Genes de Plantas/genética , Genes de Plantas/fisiología , ARN Mensajero/metabolismo
5.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 38(6): 637-641, 2020 Dec 01.
Artículo en Chino | MEDLINE | ID: mdl-33377339

RESUMEN

OBJECTIVE: To compare the anti-caries effect and safety of Er:YAG laser combined with fluoride and methylene blue-photodynamic therapy (MB-PDT). METHODS: A total of 28 rat dental caries models were established and randomly divided into seven groups: photodynamic therapy (PDT) group, laser combined with fluoride group, laser group, sodium fluoride group, and 0.9% saline control group. Spectrophotometric optical density was used to reflect the growth of Streptococcus mutans. Laser-induced fluorescence diagnostic (LF) instrument was utilized to detect the demineralization degree of dental caries. Histopathological sections were employed to observe the damage of dental pulp and buccal mucosa. RESULTS: The optical density (OD) value of the PDT and combination groups was significantly lower than that of other treatment groups (P<0.05). An increase in LF value and demineralization occurred in varying degrees with different treatment methods. Histopathological observation showed that pulp and buccal mucosa injury was more obvious in the combination group of 70 mw·cm⁻² and Er:YAG laser group compared with other groups. CONCLUSIONS: Under the same parameters, the combined group and PDT have good germicidal efficacy, but PDT has fewer adverse reactions and less damage. It is an effective and safe method for caries prevention.


Asunto(s)
Caries Dental , Terapia por Láser , Láseres de Estado Sólido , Fotoquimioterapia , Cariostáticos , Caries Dental/prevención & control , Fluoruros , Humanos , Azul de Metileno
6.
Nat Commun ; 10(1): 4359, 2019 09 25.
Artículo en Inglés | MEDLINE | ID: mdl-31554790

RESUMEN

Ensuring that one gene's transcription does not inappropriately affect the expression of its neighbors is a fundamental challenge to gene regulation in a genomic context. In plants, which lack homologs of animal insulator proteins, the mechanisms that prevent transcriptional interference are not well understood. Here we show that BORDER proteins are enriched in intergenic regions and prevent interference between closely spaced genes on the same strand by promoting the 3' pausing of RNA polymerase II at the upstream gene. In the absence of BORDER proteins, 3' pausing associated with the upstream gene is reduced and shifts into the promoter region of the downstream gene. This is consistent with a model in which BORDER proteins inhibit transcriptional interference by preventing RNA polymerase from intruding into the promoters of downstream genes.


Asunto(s)
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Regulación del Desarrollo de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Raíces de Plantas/genética , ARN Polimerasa II/genética , Factores de Elongación Transcripcional/genética , Arabidopsis/crecimiento & desarrollo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Perfilación de la Expresión Génica/métodos , Mutación , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , ARN Polimerasa II/metabolismo , Plantones/genética , Plantones/crecimiento & desarrollo , Plantones/metabolismo , Factores de Elongación Transcripcional/metabolismo
7.
Mol Omics ; 15(4): 271-279, 2019 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-31099812

RESUMEN

Salvianic acid A sodium (SAAS), derived from a well-known herbal medicine Danshen (Salvia miltiorrhiza), is a new drug involved in phase I clinical trials in China for the treatment of coronary heart disease and stable angina pectoris. However, the direct binding protein(s) of SAAS are not understood and the broader cardioprotective effects as well as the underlying mechanisms remain to be further elucidated. In this study, Sprague-Dawley rats were subjected to left anterior descending artery ligation to investigate the cardioprotective effect of SAAS against myocardial infarction (MI). Moreover, a human proteome microarray was used to identify the direct binding proteins of SAAS, which was further verified by metabolomic profiling of rat serum after MI using an ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) based approach. Our results demonstrated that SAAS significantly improved cardiac function and protected against MI-induced injury. In total, 370 proteins were identified to specifically bind SAAS and strikingly enriched in metabolic pathways. Rat serum metabolomic profiling identified 26 potential biomarkers including various glycerophospholipids (GPLs) and an array of fatty acids. Metabolic pathway analysis found increased phospholipid catabolism, sphingolipid metabolism and linoleic acid metabolism, decreased tryptophan metabolism, and impaired glycerophospholipid metabolism and primary bile acid biosynthesis in MI animals, while SAAS remarkably reversed these metabolic changes. SAAS may protect against myocardial infarction in rats by reversing multiple metabolic changes-induced by MI injury. Our findings will shed light on the cardioprotective mechanism of SAAS and aid its clinical use. Moreover, the SAAS-binding proteins identified by the proteome microarray are expected to be a valuable resource for its greater development.


Asunto(s)
Cardiotónicos/metabolismo , Lactatos/metabolismo , Infarto del Miocardio/metabolismo , Proteoma/metabolismo , Animales , Biomarcadores/sangre , Biomarcadores/química , Cardiotónicos/química , Cardiotónicos/uso terapéutico , China , Cromatografía Líquida de Alta Presión , Ácidos Grasos/metabolismo , Lactatos/uso terapéutico , Metabolismo de los Lípidos , Masculino , Espectrometría de Masas , Metabolómica , Infarto del Miocardio/sangre , Infarto del Miocardio/tratamiento farmacológico , Infarto del Miocardio/prevención & control , Análisis por Matrices de Proteínas , Ratas , Ratas Sprague-Dawley , Salvia miltiorrhiza/química
8.
Clin Exp Pharmacol Physiol ; 45(6): 514-524, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29193272

RESUMEN

This study was designed to investigate the possible synergism of amlodipine and candesartan on the reduction of blood pressure (BP) in hypertensive rats. The end organ protection was also observed. In acute experiment, spontaneously hypertensive rats (SHRs) were treated with intragastric administration of amlodipine (0.5, 1, 2, 3 mg/kg), candesartan (1, 2, 3, 4, 6, 8 mg/kg), and 14 different combinations to find the possible ratio of synergistic interaction. In two kidneys, one clip (2K1C) rats, the effects of amlodipine (1 mg/kg), canderastan (2 mg/kg) and their combination on BP reduction were also observed. In chronic study, SHRs were treated with amlodipine (1 mg/kg), candesartan (2 mg/kg), and their combination for 5 months. Organ damage evaluation was performed after BP recording. The probability sum test (q test) was used to evaluate the synergistic action. There is a synergistic interaction between amlodipine and candesartan on BP reduction. The optimal dose ratio is 1:2. The synergistic effect was also confirmed by 2K1C hypertensive rats. In chronic study, this combination (1:2) possessed an obvious synergism on the reduction of BP and BP variability (BPV) and protection on end organs. Multiple regression analysis showed that heart and aortic hypertrophy indexes and glomerular damage parameters were positively related to BP and BPV. In conclusion, combination of amlodipine and candesartan exhibited a potent antihypertensive effect and possessed an obvious synergism on BP reduction and organ protection in hypertension. The optimal proportion was 1:2. BP and BPV reduction may both importantly contribute to end organ protection.


Asunto(s)
Amlodipino/efectos adversos , Amlodipino/farmacología , Antihipertensivos/efectos adversos , Antihipertensivos/farmacología , Bencimidazoles/efectos adversos , Bencimidazoles/farmacología , Presión Sanguínea/efectos de los fármacos , Tetrazoles/efectos adversos , Tetrazoles/farmacología , Animales , Compuestos de Bifenilo , Relación Dosis-Respuesta a Droga , Sinergismo Farmacológico , Frecuencia Cardíaca/efectos de los fármacos , Masculino , Ratas , Ratas Sprague-Dawley , Factores de Tiempo
10.
Sci Rep ; 7: 40986, 2017 01 27.
Artículo en Inglés | MEDLINE | ID: mdl-28128226

RESUMEN

Susceptibility to motion sickness (MS) varies considerably among humans. However, the cause of such variation is unclear. Here, we used a classical genetic approach to obtain mouse strains highly sensitive and resistant to MS (SMS and RMS). Proteomics analysis revealed substantially lower swiprosin-1 expression in SMS mouse brains. Inducing MS via rotary stimulation decreased swiprosin-1 in the mouse brains. Swiprosin-1 knockout mice were much more sensitive to motion disturbance. Immunohistochemistry revealed strong swiprosin-1 expression in the vestibular nuclei (VN). Over-expressing swiprosin-1 in the VN of SMS mice decreased MS susceptibility. Down-regulating swiprosin-1 in the VN of RMS mice by RNAi increased MS susceptibility. Additional in vivo experiments revealed decreased swiprosin-1 expression by glutamate via the NMDA receptor. Glutamate increased neuronal excitability in SMS or swiprosin-1 knockout mice more prominently than in RMS or wild-type mice. These results indicate that swiprosin-1 in the VN is a critical determinant of the susceptibility to MS.


Asunto(s)
Proteínas de Unión al Calcio/análisis , Mareo por Movimiento/patología , Núcleos Vestibulares/patología , Animales , Proteínas de Unión al Calcio/genética , Inmunohistoquímica , Ratones Noqueados , Proteómica
11.
CNS Neurosci Ther ; 22(8): 715-22, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27160425

RESUMEN

BACKGROUND AND AIMS: Severe motion sickness is a huge obstacle for people conducting precise aviation, marine or emergency service tasks. The combination of scopolamine and d-amphetamine is most effective in preventing severe motion sickness. However, this combination is not included in any present pharmacopoeia due to the abuse liability of d-amphetamine. We wanted to find a combination to replace it for the treatment of severe motion sickness. METHODS AND RESULTS: We compared the efficacy of scopolamine, diphenhydramine, and granisetron (representing three classes of drugs) with different doses, and found that scopolamine was the most effective one. We also found scopolamine inhibited central nervous system at therapeutic doses and caused anxiety. Then, we combined it with different doses of psychostimulants (d-amphetamine, modafinil, caffeine) to find the best combination for motion sickness. The efficacy of scopolamine with modafinil (1 + 10 mg/kg) was equivalent to that of scopolamine with d-amphetamine (1 + 1 mg/kg); This combination also excited central nervous system and abolished the anxiety caused by scopolamine. CONCLUSIONS: The optimal dose ratio of scopolamine and modafinil is 1:10. This combination is beneficial for motion sickness and can abolish the side effects of scopolamine. So, it might be a good replacement of scopolamine and d-amphetamine for severe motion sickness.


Asunto(s)
Estimulantes del Sistema Nervioso Central/uso terapéutico , Antagonistas Colinérgicos/uso terapéutico , Mareo por Movimiento/prevención & control , Escopolamina/uso terapéutico , Análisis de Varianza , Animales , Compuestos de Bencidrilo/farmacología , Cafeína/uso terapéutico , Dextroanfetamina/farmacología , Difenhidramina/uso terapéutico , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Combinación de Medicamentos , Granisetrón/uso terapéutico , Locomoción/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos ICR , Modafinilo , Mareo por Movimiento/etiología , Rotación/efectos adversos
12.
Mol Plant ; 8(4): 631-43, 2015 04.
Artículo en Inglés | MEDLINE | ID: mdl-25792146

RESUMEN

Arabidopsis cryptochrome 2 (CRY2) is a blue light receptor that mediates light inhibition of hypocotyl elongation and long-day promotion of floral initiation. CRY2 is known to undergo blue light-dependent phosphorylation, which is believed to serve regulatory roles in the function of CRY2. We report here on a biochemical and genetics study of CRY2 phosphorylation. Using mass spectrometry analysis, we identified three serine residues in the CCE domain of CRY2 (S598, S599, and S605) that undergo blue light-dependent phosphorylation in Arabidopsis seedlings. A study of serine-substitution mutations in the CCE domain of CRY2 demonstrates that CRY2 contains two types of phosphorylation in the CCE domain, one in the serine cluster that causes electrophoretic mobility upshift and the other outside the serine cluster that does not seem to cause mobility upshift. We showed that mutations in the serine residues within and outside the serine cluster diminished blue light-dependent CRY2 phosphorylation, degradation, and physiological activities. These results support the hypothesis that blue light-dependent phosphorylation of the CCE domain determines the photosensitivity of Arabidopsis CRY2.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Criptocromos/metabolismo , Luz , Arabidopsis/efectos de la radiación , Proteínas de Arabidopsis/genética , Criptocromos/genética , Regulación de la Expresión Génica de las Plantas/genética , Regulación de la Expresión Génica de las Plantas/efectos de la radiación , Fosforilación/efectos de la radiación
13.
Proc Biol Sci ; 280(1763): 20131043, 2013 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-23698015

RESUMEN

An evolutionary response to selection requires genetic variation; however, even if it exists, then the genetic details of the variation can constrain adaptation. In the simplest case, unlinked loci and uncorrelated phenotypes respond directly to multivariate selection and permit unrestricted paths to adaptive peaks. By contrast, 'antagonistic' pleiotropic loci may constrain adaptation by affecting variation of many traits and limiting the direction of trait correlations to vectors that are not favoured by selection. However, certain pleiotropic configurations may improve the conditions for adaptive evolution. Here, we present evidence that the Arabidopsis thaliana gene FRI (FRIGIDA) exhibits 'adaptive' pleiotropy, producing trait correlations along an axis that results in two adaptive strategies. Derived, low expression FRI alleles confer a 'drought escape' strategy owing to fast growth, low water use efficiency and early flowering. By contrast, a dehydration avoidance strategy is conferred by the ancestral phenotype of late flowering, slow growth and efficient water use during photosynthesis. The dehydration avoidant phenotype was recovered when genotypes with null FRI alleles were transformed with functional alleles. Our findings indicate that the well-documented effects of FRI on phenology result from differences in physiology, not only a simple developmental switch.


Asunto(s)
Adaptación Fisiológica/genética , Proteínas de Arabidopsis/genética , Arabidopsis/genética , Arabidopsis/fisiología , Genes de Plantas , Pleiotropía Genética , Alelos , Arabidopsis/crecimiento & desarrollo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Evolución Biológica , Sequías , Flores/genética , Flores/crecimiento & desarrollo , Flores/fisiología , Regulación de la Expresión Génica de las Plantas , Variación Genética , Genotipo , Fenotipo
14.
J Chemother ; 24(5): 257-67, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23182045

RESUMEN

Community-acquired pneumonia (CAP) is a leading cause of morbidity and mortality throughout the world. To investigate whether moxifloxacin monotherapy is associated with better clinical outcomes than other antibiotics recommended for CAP among adults with mild-to-moderate or severe CAP, we performed a meta-analysis. MEDLINE, EMBASE, Web of Science, and the Cochrane Library were searched for randomized control trials (RCTs). The efficacy and safety of moxifloxacin were compared with other antimicrobial agents used to treat CAP. Fourteen RCTs, consisting of 6923 total patients, were included in the meta-analysis. No difference was found regarding the incidence of adverse events and mortality between moxifloxacin and the compared regimens. We found that moxifloxacin is as effective and well-tolerated as other recommended antibiotics for the treatment of CAP and possesses a better pathogen eradication rate than beta-lactam-based therapy.


Asunto(s)
Antibacterianos/uso terapéutico , Compuestos Aza/uso terapéutico , Neumonía Bacteriana/tratamiento farmacológico , Quinolinas/uso terapéutico , Ensayos Clínicos Controlados Aleatorios como Asunto , Infecciones Comunitarias Adquiridas/tratamiento farmacológico , Fluoroquinolonas , Humanos , Moxifloxacino
15.
Plant Physiol ; 160(3): 1373-83, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22991283

RESUMEN

Complex I (NADH:ubiquinone oxidoreductase) is the entry point for electrons into the respiratory electron transport chain; therefore, it plays a central role in cellular energy metabolism. Complex I from different organisms has a similar basic structure. However, an extra structural module, referred to as the γ-carbonic anhydrase (γCA) subcomplex, is found in the mitochondrial complex I of photoautotrophic eukaryotes, such as green alga and plants, but not in that of the heterotrophic eukaryotes, such as fungi and mammals. It has been proposed that the γCA subcomplex is required for the light-dependent life style of photoautotrophic eukaryotes, but this hypothesis has not been successfully tested. We report here a genetic study of the genes γCAL1 and γCAL2 that encode two subunits of the γCA subcomplex of mitochondrial complex I. We found that mutations of γCAL1 and γCAL2 in Arabidopsis (Arabidopsis thaliana) result in defective embryogenesis and nongerminating seeds, demonstrating the functional significance of the γCA subcomplex of mitochondrial complex I in plant development. Surprisingly, we also found that reduced expression of γCAL1 and γCAL2 genes altered photomorphogenic development. The γcal1 mutant plant expressing the RNA interference construct of the γCAL2 gene showed a partial constitutive photomorphogenic phenotype in young seedlings and a reduced photoperiodic sensitivity in adult plants. The involvement of the γCA subcomplex of mitochondrial complex I in plant photomorphogenesis and the possible evolutionary significance of this plant-specific mitochondrial protein complex are discussed.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crecimiento & desarrollo , Anhidrasas Carbónicas/metabolismo , Complejo I de Transporte de Electrón/metabolismo , Luz , Morfogénesis/efectos de la radiación , Arabidopsis/enzimología , Arabidopsis/genética , Arabidopsis/efectos de la radiación , Proteínas de Arabidopsis/genética , Anhidrasas Carbónicas/genética , Complejo I de Transporte de Electrón/genética , Regulación de la Expresión Génica de las Plantas/efectos de la radiación , Genes de Plantas/genética , Prueba de Complementación Genética , Genotipo , Germinación/efectos de la radiación , Proteínas Mitocondriales/genética , Proteínas Mitocondriales/metabolismo , Mutación/genética , Fenotipo , Fotoperiodo , Plantas Modificadas Genéticamente , Semillas/crecimiento & desarrollo , Semillas/efectos de la radiación , Especificidad de la Especie
16.
Development ; 139(18): 3402-12, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22912415

RESUMEN

When a plant germinates in the soil, elongation of stem-like organs is enhanced whereas leaf and root growth is inhibited. How these differential growth responses are orchestrated by light and integrated at the organismal level to shape the plant remains to be elucidated. Here, we show that light signals through the master photomorphogenesis repressor COP1 to coordinate root and shoot growth in Arabidopsis. In the shoot, COP1 regulates shoot-to-root auxin transport by controlling the transcription of the auxin efflux carrier gene PIN-FORMED1 (PIN1), thus appropriately tuning shoot-derived auxin levels in the root. This in turn directly influences root elongation and adapts auxin transport and cell proliferation in the root apical meristem by modulating PIN1 and PIN2 intracellular distribution in the root in a COP1-dependent fashion, thus permitting a rapid and precise tuning of root growth to the light environment. Our data identify auxin as a long-distance signal in developmental adaptation to light and illustrate how spatially separated control mechanisms can converge on the same signaling system to coordinate development at the whole plant level.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Ácidos Indolacéticos/metabolismo , Luz , Proteínas de Transporte de Membrana/metabolismo , Raíces de Plantas/metabolismo , Brotes de la Planta/metabolismo , Arabidopsis/genética , Arabidopsis/efectos de la radiación , Proteínas de Arabidopsis/genética , Transporte Biológico/genética , Transporte Biológico/efectos de la radiación , Regulación de la Expresión Génica de las Plantas/genética , Regulación de la Expresión Génica de las Plantas/efectos de la radiación , Proteínas de Transporte de Membrana/genética , Raíces de Plantas/genética , Raíces de Plantas/efectos de la radiación , Brotes de la Planta/genética , Brotes de la Planta/efectos de la radiación , Ubiquitina-Proteína Ligasas
17.
Mol Plant ; 5(3): 726-33, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22311776

RESUMEN

Arabidopsis cryptochrome 2 (CRY2) is a blue-light receptor mediating blue-light inhibition of hypocotyl elongation and photoperiodic promotion of floral initiation. CRY2 is a constitutive nuclear protein that undergoes blue-light-dependent phosphorylation, ubiquitination, photobody formation, and degradation in the nucleus, but the relationship between these blue-light-dependent events remains unclear. It has been proposed that CRY2 phosphorylation triggers a conformational change responsible for the subsequent ubiquitination and photobody formation, leading to CRY2 function and/or degradation. We tested this hypothesis by a structure-function study, using mutant CRY2-GFP fusion proteins expressed in transgenic Arabidopsis. We show that changes of lysine residues of the NLS (Nuclear Localization Signal) sequence of CRY2 to arginine residues partially impair the nuclear importation of the CRY2K541R and CRY2K554/5R mutant proteins, resulting in reduced phosphorylation, physiological activities, and degradation in response to blue light. In contrast to the wild-type CRY2 protein that forms photobodies exclusively in the nucleus, the CRY2K541R and CRY2K554/5R mutant proteins form protein bodies in both the nucleus and cytosol in response to blue light. These results suggest that photoexcited CRY2 molecules can aggregate to form photobody-like structure without the nucleus-dependent protein modifications or the association with the nuclear CRY2-interacting proteins. Taken together, the observation that CRY2 forms photobodies markedly faster than CRY2 phosphorylation in response to blue light, we hypothesize that the photoexcited cryptochromes form oligomers, preceding other biochemical changes of CRY2, to facilitate photobody formation, signal amplification, and propagation, as well as desensitization by degradation.


Asunto(s)
Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Arabidopsis/efectos de la radiación , Criptocromos/química , Criptocromos/metabolismo , Luz , Proteolisis/efectos de la radiación , Secuencia de Aminoácidos , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Núcleo Celular/metabolismo , Núcleo Celular/efectos de la radiación , Hipocótilo/crecimiento & desarrollo , Hipocótilo/efectos de la radiación , Lisina/metabolismo , Datos de Secuencia Molecular , Proteínas Mutantes/química , Proteínas Mutantes/metabolismo , Mutación/genética , Señales de Localización Nuclear/química , Señales de Localización Nuclear/metabolismo , Fosforilación/efectos de la radiación , Plantas Modificadas Genéticamente , Estructura Cuaternaria de Proteína , Transporte de Proteínas/efectos de la radiación
18.
J Antimicrob Chemother ; 67(2): 255-68, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22096042

RESUMEN

Fosfomycin has attracted renewed interest for the treatment of lower urinary tract and even systemic infections caused by Gram-negative pathogens with resistance to traditionally used agents. The main concern regarding the clinical utility of fosfomycin refers to the potential for the emergence of resistance during therapy. In this review, we evaluate the available published evidence regarding the mechanisms and the frequency of in vitro mutational resistance to fosfomycin in Gram-negative pathogens. We also review data regarding the emergence of resistance in clinical studies of fosfomycin therapy in various infectious syndromes and data from studies that evaluate the evolution of fosfomycin resistance over time. There appears to be discordance between the high frequency of mutational resistance to fosfomycin in vitro and the lower extent of this phenomenon in clinical studies. This discordance could at least partly be attributed to a biological cost associated with common mutations that confer resistance to fosfomycin, including decreased growth rate and low adherence to epithelial cells for the resistant mutants. The development of resistance appears to be more frequent both in vitro and in clinical studies for Pseudomonas aeruginosa in comparison with Escherichia coli, whereas relevant data for other Enterobacteriaceae are relatively scarce. The urinary tract seems to provide a favourable environment for the use of fosfomycin with a low associated likelihood for the emergence of resistance, owing to high drug concentrations and acidic pH. Additional data are needed to further clarify the optimal use of fosfomycin for different infectious syndromes caused by contemporary multidrug-resistant pathogens.


Asunto(s)
Antibacterianos/farmacología , Farmacorresistencia Bacteriana , Enterobacteriaceae/efectos de los fármacos , Fosfomicina/farmacología , Infecciones por Bacterias Gramnegativas/microbiología , Pseudomonas aeruginosa/efectos de los fármacos , Antibacterianos/uso terapéutico , Fosfomicina/uso terapéutico , Infecciones por Bacterias Gramnegativas/tratamiento farmacológico , Humanos , Mutación
19.
Proc Natl Acad Sci U S A ; 108(51): 20844-9, 2011 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-22139370

RESUMEN

Cryptochromes are blue-light receptors mediating various light responses in plants and animals. The photochemical mechanism of cryptochromes is not well understood. It has been proposed that photoactivation of cryptochromes involves the blue-light-dependent photoreduction of flavin adenine dinucleotide via the electron transport chain composed of three evolutionarily conserved tryptophan residues known as the "trp triad." We investigated this hypothesis by analyzing the photochemical and physiological activities of Arabidopsis cryptochrome 2 (CRY2) mutations altered in each of the three trp-triad residues. We found that all trp-triad mutations of CRY2 tested lost photoreduction activity in vitro but retained the physiological and biochemical activities in vivo. Some of the trp-triad mutations of CRY2 remained responsive to blue light; others, such as CRY2(W374A), became constitutively active. In contrast to wild-type CRY2, which undergoes blue-light-dependent interaction with the CRY2-signaling proteins SUPPRESSOR OF PHYA 1 (SPA1) and cryptochrome-interaction basic helix-loop-helix 1 (CIB1), the constitutively active CRY2(W374A) interacts with SPA1 and CIB1 constitutively. These results support the hypothesis that cryptochromes mediate blue-light responses via a photochemistry distinct from trp-triad-dependent photoreduction and that the trp-triad residues are evolutionarily conserved in the photolyase/cryptochrome superfamily for reasons of structural integrity rather than for photochemistry per se.


Asunto(s)
Arabidopsis/metabolismo , Criptocromos/química , Triptófano/química , Proteínas de Arabidopsis/metabolismo , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Proteínas de Ciclo Celular/metabolismo , Criptocromos/genética , Criptocromos/fisiología , Luz , Modelos Genéticos , Modelos Moleculares , Conformación Molecular , Mutagénesis Sitio-Dirigida , Oxidación-Reducción , Fotoquímica/métodos , Estructura Terciaria de Proteína
20.
J Antibiot (Tokyo) ; 64(8): 559-62, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21772306

RESUMEN

This study aimed to evaluate the in vitro activity of minocycline combined with fosfomycin against isolates of methicillin-resistant Staphylococcus aureus (MRSA). A total of 87 clinical isolates of MRSA collected from three Chinese hospitals were included in the study. The checkerboard method with determination of the fractional IC index (FICI) was used to determine whether antibiotic combinations act synergistically against these isolates. The susceptibility results for minocycline and fosfomycin were interpreted according to the most relevant criteria. The results demonstrated the following interactions: 76 isolates (87.4%) showed synergistic interactions (FICI0.5) and 11 isolates (12.6%) showed indifferent interactions (0.5

Asunto(s)
Antibacterianos/farmacología , Fosfomicina/farmacología , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Minociclina/farmacología , China , Interacciones Farmacológicas , Hospitales , Humanos , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Pruebas de Sensibilidad Microbiana , Infecciones Estafilocócicas/microbiología
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