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881.
Jose Sergio M. Soares Agustina Gentile Valeria Scorsato Aline da C. Lima Eduardo Kiyota Marcelo Leite dos Santos Claudia V. Piattoni Steven C. Huber Ricardo Aparicio Marcelo Menossi 《The Journal of biological chemistry》2014,289(48):33364-33377
Sugarcane is a monocot plant that accumulates sucrose to levels of up to 50% of dry weight in the stalk. The mechanisms that are involved in sucrose accumulation in sugarcane are not well understood, and little is known with regard to factors that control the extent of sucrose storage in the stalks. UDP-glucose pyrophosphorylase (UGPase; EC 2.7.7.9) is an enzyme that produces UDP-glucose, a key precursor for sucrose metabolism and cell wall biosynthesis. The objective of this work was to gain insights into the ScUGPase-1 expression pattern and regulatory mechanisms that control protein activity. ScUGPase-1 expression was negatively correlated with the sucrose content in the internodes during development, and only slight differences in the expression patterns were observed between two cultivars that differ in sucrose content. The intracellular localization of ScUGPase-1 indicated partial membrane association of this soluble protein in both the leaves and internodes. Using a phospho-specific antibody, we observed that ScUGPase-1 was phosphorylated in vivo at the Ser-419 site in the soluble and membrane fractions from the leaves but not from the internodes. The purified recombinant enzyme was kinetically characterized in the direction of UDP-glucose formation, and the enzyme activity was affected by redox modification. Preincubation with H2O2 strongly inhibited this activity, which could be reversed by DTT. Small angle x-ray scattering analysis indicated that the dimer interface is located at the C terminus and provided the first structural model of the dimer of sugarcane UGPase in solution. 相似文献
882.
Éder Ricardo Petry Vinicius Fernandes Cruzat Thiago Gomes Heck Jaqueline Santos Moreira Leite Paulo Ivo Homem de Bittencourt Jr. Julio Tirapegui 《Life sciences》2014
Aims
We hypothesized that oral l-glutamine supplementations could attenuate muscle damage and oxidative stress, mediated by glutathione (GSH) in high-intensity aerobic exercise by increasing the 70-kDa heat shock proteins (HSP70) and heat shock factor 1 (HSF1).Main methods
Adult male Wistar rats were 8-week trained (60-min/day, 5 days/week) on a treadmill. During the last 21 days, the animals were supplemented with either l-alanyl-l-glutamine dipeptide (1.5 g/kg, DIP) or a solution containing the amino acids l-glutamine (1 g/kg) and l-alanine (0.67 g/kg) in their free form (GLN + ALA) or water (controls).Key findings
Plasma from both DIP- and GLN + ALA-treated animals showed higher l-glutamine concentrations and reduced ammonium, malondialdehyde, myoglobin and creatine kinase activity. In the soleus and gastrocnemius muscle of both supplemented groups, l-glutamine and GSH contents were increased and GSH disulfide (GSSG) to GSH ratio was attenuated (p < 0.001). In the soleus muscle, cytosolic and nuclear HSP70 and HSF1 were increased by DIP supplementation. GLN + ALA group exhibited higher HSP70 (only in the nucleus) and HSF1 (cytosol and nucleus). In the gastrocnemius muscle, both supplementations were able to increase cytosolic HSP70 and cytosolic and nuclear HSF1.Significance
In trained rats, oral supplementation with DIP or GLN + ALA solution increased the expression of muscle HSP70, favored muscle l-glutamine/GSH status and improved redox defenses, which attenuate markers of muscle damage, thus improving the beneficial effects of high-intensity exercise training. 相似文献883.
The present study investigated the anticonvulsant and convulsant profiles of nantenine, an aporphine alkaloid found in several vegetal species. At lower doses (20-50 mg/kg, i.p.) the alkaloid proved to be effective in inhibiting pentylenotetrazol- (PTZ 100 mg/kg, s.c.) and maximal electroshock-induced seizures (80 mA, 50 pulses/s, 0.2 s), suggesting its potential as an anticonvulsant drug. However, at higher doses (> or = 75 mg/kg, i.p.) a convulsant activity was observed. Comparing the present in vivo nantenine effects on seizures with previous in vitro biphasic action on Na+, K+-ATPase activity, the convulsant effect appears to be related to inhibition of these phosphatase at high doses whereas anticonvulsant effect, observed at low doses, seems attributable to its stimulation and the resultant decrease of Ca2+-influx into the cell. 相似文献
884.
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886.
Marcela de Castro Nunes Santos Terra Rubens Manoel dos Santos Marco Aurélio Leite Fontes José Marcio de Mello José Roberto Soares Scolforo Lucas Rezende Gomide Jamir Afonso do Prado Júnior Ivan Schiavini Hans ter Steege 《Biodiversity and Conservation》2017,26(9):2133-2153
Quantifying diversity is an old challenge for ecologists and is also a social demand given the increasing threats to natural areas. We sought to work on these issues by using data from 158 vegetation remnants (over 350,000 trees) in southeastern Brazil (Minas Gerais State—MG, nearly 600,000 km2). Specifically, we sought to answer the following questions. (1) How many trees and tree species currently exist in MG vegetation remnants? (2) How much of such biodiversity is present in each vegetation domain (Atlantic Forest, Cerrado and Caatinga) and vegetation type (Seasonally Dry tropical forest “semideciduous”, Seasonally Dry tropical forest “deciduous”, Rain Forest, Swamp, Cerrado and Cerradão) in MG? (3) How much has been lost in regards to tree amount and tree species? We built a 0.1-degree cell grid to estimate the number of trees via spatial regression and used Fisher’s alpha and Fisher’s log series to provide estimates on how many tree species there are and were in MG. We found the number of trees in Minas Gerais to be approximately 24.5 × 109, and the number of tree species to be between 3592 and 3743. The most abundant species distribution among the vegetation domains and vegetation types followed inversely the environmental heterogeneity of the classes. Consequently, the most abundant species in MG belonged to the Cerrado domain, where there was less environmental heterogeneity. The numbers of trees and tree species lost were estimated at 68.54 and 4.03–8.42% of the original values, respectively. We discuss that due to the consequences of human impacts that go back in the region for over a thousand years, other processes not considered in this study, such as habitat degradation by isolation, alterations of food webs, unsustainable use, and climate change, might have caused local extinctions and potentially increased the number of species lost. We believe our results may guide conservation initiatives by providing a base for future environmental laws, parks planning, and the development of more appropriate vegetation management techniques in MG. In addition, our results may inspire future quantitative ecological studies in the tropics. 相似文献
887.
Influence of shading and pedestrian traffic on the preference of Aedes (Stegomyia) aegypti (Diptera: Culicidae) for oviposition microenvironments
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Aedes aegypti mosquitoes are highly adaptable to abiotic stimuli. To evaluate the influence of shading and pedestrian traffic on the preference of Ae. aegypti for oviposition microenvironments, 20 sites were sampled weekly using ovitraps within the perimeter of Universidade Federal do Espírito Santo, located in São Mateus, Espírito Santo, Brazil. A spatial and statistical analysis was performed in order to assess the relationship between shading time, pedestrian traffic, and the presence of biological forms of Ae. aegypti. A temporal analysis of temperature and precipitation influence on oviposition was also made. Between June, 2013 and June, 2014, 7,362 Ae. aegypti eggs were collected. Over a 12‐month period, we made weekly collections of Ae. aegypti eggs from ovitraps. Pedestrian traffic and shading time influenced the number of positive ovitraps; precipitation and temperature were correlated with the number of positive ovitraps (p <0.05). We conclude that the influence of temperature and precipitation was not significant for the oviposition index, and the frequency of oviposition was directly proportional to the number of individuals moving close to the traps during periods of greater shading. 相似文献
888.
Combined Therapy With Swimming Exercise and a Diet Supplemented With Diphenyl Diselenide Is Effective Against Age‐Related Changes in the Hepatic Metabolism of Rats
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889.
Evolutionarily significant units of the critically endangered leaf frog Pithecopus ayeaye (Anura,Phyllomedusidae) are not effectively preserved by the Brazilian protected areas network
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Rafael Félix de Magalhães Priscila Lemes Arley Camargo Ubirajara Oliveira Reuber Albuquerque Brandão Hans Thomassen Paulo Christiano de Anchietta Garcia Felipe Sá Fortes Leite Fabrício Rodrigues Santos 《Ecology and evolution》2017,7(21):8812-8828
Protected areas (PAs) are essential for biodiversity conservation, but their coverage is considered inefficient for the preservation of all species. Many species are subdivided into evolutionarily significant units (ESUs) and the effectiveness of PAs in protecting them needs to be investigated. We evaluated the usefulness of the Brazilian PAs network in protecting ESUs of the critically endangered Pithecopus ayeaye through ongoing climate change. This species occurs in a threatened mountaintop ecosystem known as campos rupestres. We used multilocus DNA sequences to delimit geographic clusters, which were further validated as ESUs with a coalescent approach. Ecological niche modeling was used to estimate spatial changes in ESUs’ potential distributions, and a gap analysis was carried out to evaluate the effectiveness of the Brazilian PAs network to protect P. ayeaye in the face of climate changes. We tested the niche overlap between ESUs to gain insights for potential management alternatives for the species. Pithecopus ayeaye contains at least three ESUs isolated in distinct mountain regions, and one of them is not protected by any PA. There are no climatic niche differences between the units, and only 4% of the suitable potential area of the species is protected in present and future projections. The current PAs are not effective in preserving the intraspecific diversity of P. ayeaye in its present and future range distributions. The genetic structure of P. ayeaye could represent a typical pattern in campos rupestres endemics, which should be considered for evaluating its conservation status. 相似文献
890.
Comparative genomics of two Leptospira interrogans serovars reveals novel insights into physiology and pathogenesis 总被引:15,自引:0,他引:15
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Nascimento AL Ko AI Martins EA Monteiro-Vitorello CB Ho PL Haake DA Verjovski-Almeida S Hartskeerl RA Marques MV Oliveira MC Menck CF Leite LC Carrer H Coutinho LL Degrave WM Dellagostin OA El-Dorry H Ferro ES Ferro MI Furlan LR Gamberini M Giglioti EA Góes-Neto A Goldman GH Goldman MH Harakava R Jerônimo SM Junqueira-de-Azevedo IL Kimura ET Kuramae EE Lemos EG Lemos MV Marino CL Nunes LR de Oliveira RC Pereira GG Reis MS Schriefer A Siqueira WJ Sommer P Tsai SM Simpson AJ Ferro JA Camargo LE 《Journal of bacteriology》2004,186(7):2164-2172