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101.
Rice calcium‐dependent protein kinase OsCPK17 targets plasma membrane intrinsic protein and sucrose‐phosphate synthase and is required for a proper cold stress response 下载免费PDF全文
M. Cecília Almadanim Bruno M. Alexandre Margarida T.G. Rosa Helena Sapeta António E. Leitão José C. Ramalho TuKiet T. Lam Sónia Negrão Isabel A. Abreu M. Margarida Oliveira 《Plant, cell & environment》2017,40(7):1197-1213
Calcium‐dependent protein kinases (CDPKs) are involved in plant tolerance mechanisms to abiotic stresses. Although CDPKs are recognized as key messengers in signal transduction, the specific role of most members of this family remains unknown. Here, we test the hypothesis that OsCPK17 plays a role in rice cold stress response by analysing OsCPK17 knockout, silencing and overexpressing rice lines under low temperature. Altered OsCPK17 gene expression compromises cold tolerance performance, without affecting the expression of key cold stress‐inducible genes. A comparative phosphoproteomic approach led to the identification of six potential in vivo OsCPK17 targets, which are associated with sugar and nitrogen metabolism, and with osmotic regulation. To test direct interaction, in vitro kinase assays were performed, showing that the sucrose‐phosphate synthase OsSPS4 and the aquaporin OsPIP2;1/OsPIP2;6 are phosphorylated by OsCPK17 in a calcium‐dependent manner. Altogether, our data indicates that OsCPK17 is required for a proper cold stress response in rice, likely affecting the activity of membrane channels and sugar metabolism. 相似文献
102.
A. T. Natarajan S. J. Santos F. Darroudi V. Hadjidikova S. Vermeulen S. Chatterjee M. v/d Berg M. Grigorova E. T. Sakamoto-Hojo F. Granath A. T. Ramalho M. P. Curado 《Mutation research》1998,400(1-2):299-312
The radiation accident in focus here occurred in a section of Goiânia (Brazil) where more than a hundred individuals were contaminated with 137Cesium on September 1987. In order to estimate the absorbed radiation doses, initial frequencies of dicentrics and rings were determined in 129 victims [A.T. Ramalho, PhD Thesis, Subsidios a tecnica de dosimetria citogenetica gerados a partir da analise de resultados obtidos com o acidente radiologico de Goiânia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil, 1992]. We have followed some of these victims cytogenetically over the years seeking for parameters that could be used as basis for retrospective radiation dosimetry. Our data on translocation frequencies obtained by fluorescence in situ hybridization (FISH) could be directly compared to the baseline frequencies of dicentrics available for those same victims. Our results provided valuable information on how precise these estimates are. The frequencies of translocations observed years after the radiation exposure were two to three times lower than the initial dicentrics frequencies, the differences being larger at higher doses (> 1 Gy). The accuracy of such dose estimates might be increased by scoring sufficient amount of cells. However, factors such as the persistence of translocation carrying lymphocytes, translocation levels not proportional to chromosome size, and inter-individual variation reduce the precision of these estimates. 相似文献
103.
Flávia Barbosa Silva Botelho Magno Antonio Patto Ramalho Ângela De Fátima Barbosa Abreu Hugo José Andrade Rosa 《Journal of Phytopathology》2011,159(3):175-180
The aim of the study was to verify whether a mixture of lines containing equal amounts of seven lines of Carioca‐type common bean, all agronomically uniform but each presenting different patterns of resistance to Colletotrichum lindemuthianum, would be less damaged by anthracnose than the individual pure lines. Plants cultured in experimental plots in Lavras, Minas Gerais, Brazil, in the dry harvest seasons of 2007 and 2008 were inoculated with a mixture of races 65, 81, 87, 89 and 337 of the pathogen, and the severity of anthracnose was evaluated at 10‐ day intervals commencing 12 days after inoculation. The progress of the disease was estimated from the coefficients of the linear regression equations (b1) and from the areas under the disease progress curves (AUDPC). The mean grain yields were determined in both experimental periods. The value of b1 for the multiline was not different from that presented by the resistant line MA‐II‐22 and indicated a slower progress of the disease over time compared with susceptible lines. There were no differences in AUDPC values between the multiline and the resistant lines. The multiline presented a grain yield that was similar to those of the most productive lines even though susceptible lines comprised more than 28% of the mixture and such lines showed the lowest yields of grain. It is concluded that the use of the mixture of lines represents a good strategy for reducing the progress of anthracnose in the field and, as a consequence, reducing loss of grain yield. 相似文献
104.
Thais C.S. Souza Daniela Josa Teodorico C. Ramalho Melissa Soares Caetano 《Molecular simulation》2013,39(7):707-713
Mycobacterium tuberculosis is a leading cause of infectious disease in the world today. This outlook is aggravated by a growing number of M. tuberculosis infections in individuals who are immunocompromised as a result of HIV infections. Thus, new and more potent anti-TB agents are necessary. Therefore, acetolactate synthase (mtALS) was selected as a target enzyme to combat M. tuberculosis. In this work, the three-dimensional molecular model of the hypothetical structure for the ALS catalytic subunit of M. tuberculosis was elucidated by homology modelling. In addition, the orientations and binding affinities of sulfonylurea inhibitors with the new structure was investigated. Our findings could be helpful for the design of new, more potent mtAHAS inhibitors. 相似文献
105.
Pedro H. S. Cesar Marcus Vinícius Cardoso Trento Thais A. Sales Tamara R. Marques Mariana A. Braga Teodorico C. Ramalho Silvana Marcussi 《Journal of cellular biochemistry》2019,120(9):14594-14603
A large number of natural compounds, such as phenolic compounds, have been scientifically evaluated in the search for enzyme inhibitors. The interactions between the phenolic compound p-coumaric acid and the enzymes present in snake venoms (used as research tools) were evaluated in vitro and in silico. The p-coumaric acid was able to inhibit 31% of the phospholipase activity induced by Bothrops alternatus venom, 27% of the hemolytic activity induced by B. moojeni, 62.5% of the thrombolytic activity induced by B. jararacussu, and approximately 27% of the activity thrombosis induced by Crotalus durissus terrificus. Previous incubation of p-coumaric acid with the venoms of B. atrox and B. jararacussu increased the coagulation time by 2.18 and 2.16-fold, respectively. The activity of serine proteases in B. atrox and B. jararacussu venoms was reduced by 60% and 66.34%, respectively. Computational chemistry analyses suggests the specific binding of p-coumaric acid to the active site of proteases through hydrogen and hydrophobic interactions. The phenolic compound evaluated in this work has great potential in therapeutic use to both prevent and treat hemostatic alterations, because the venom proteins inhibited by the p-coumaric acid have high homology with human proteins that have a fundamental role in several pathologies. 相似文献
106.
Claudia Mendon?a Bezerra Luciano Pamplona de Góes Cavalcanti Rita de Cássia Moreira de Souza Silvia Ermelinda Barbosa Samanta Cristina das Chagas Xavier Ana Maria Jansen Relrison Dias Ramalho Liléia Diotaiut 《Memórias do Instituto Oswaldo Cruz》2014,109(7):887-898
The role played by different mammal species in the maintenance of Trypanosoma
cruzi is not constant and varies in time and place. This study aimed to
characterise the importance of domestic, wild and peridomestic hosts in the
transmission of T. cruzi in Tauá, state of Ceará, Caatinga area,
Brazil, with an emphasis on those environments colonised by Triatoma
brasiliensis. Direct parasitological examinations were performed on
insects and mammals, serologic tests were performed on household and outdoor mammals
and multiplex polymerase chain reaction was used on wild mammals. Cytochrome b was
used as a food source for wild insects. The serum prevalence in dogs was 38% (20/53),
while in pigs it was 6% (2/34). The percentages of the most abundantly infected wild
animals were as follows: Thrichomys laurentius 74% (83/112)
and Kerodon rupestris 10% (11/112). Of the 749 triatomines
collected in the household research, 49.3% (369/749) were positive for T.
brasiliensis, while 6.8% were infected with T. cruzi
(25/369). In captured animals, T. brasiliensis shares a
natural environment with T. laurentius, K.
rupestris, Didelphis albiventris, Monodelphis
domestica, Galea spixii, Wiedomys
pyrrhorhinos, Conepatus semistriatus and Mus
musculus. In animals identified via their food
source, T. brasiliensis shares a natural environment with
G. spixii, K. rupestris, Capra hircus, Gallus
gallus, Tropidurus oreadicus and Tupinambis merianae.
The high prevalence of T. cruzi in household and peridomiciliar
animals reinforces the narrow relationship between the enzootic cycle and humans in
environments with T. brasiliensis and characterises it as
ubiquitous. 相似文献
107.
Mariana Lázaro Sales Antônio Augusto Fonseca Jr. Érica Bravo Sales Ana Cláudia Pinto Cottorello Marina Azevedo Issa Mikael Arrais Hodon Paulo Martins Soares Filho Alberto Knust Ramalho Marcio Roberto Silva Andrey Pereira Lage Marcos Bryan Heinemann 《Folia microbiologica》2014,59(5):433-438
Mycobacterium tuberculosis complex (MTC) comprises a group of bacteria that have a high degree of genetic similarity. Two species in this group, Mycobacterium tuberculosis and Mycobacterium bovis, are the main cause of human and bovine tuberculosis, respectively. M. bovis has a broader host range that includes humans; thus, the differentiation of mycobacterium is of great importance for epidemiological and public health considerations and to optimize treatment. The current study aimed to evaluate primers and molecular markers described in the literature to differentiate M. bovis and M. tuberculosis by PCR. Primers JB21/22, frequently cited in scientific literature, presented in our study the highest number of errors to identify M. bovis or M. tuberculosis (73 %) and primers Mb.400, designed to flank region of difference 4 (RD4), were considered the most efficient (detected all M. bovis tested and did not detect any M. tuberculosis tested). Although also designed to flank RD4, primers Mb.115 misidentified eight samples due to primer design problems. The results showed that RD4 is the ideal region to differentiate M. bovis from other bacteria classified in MTC, but primer design should be considered carefully. 相似文献
108.
Suelem D. Ramalho Lorena R. F. De Sousa Liliane Nebo Stella H. Maganhi Ignez Caracelli Julio Zukerman‐Schpector Maria Inês S. Lima Marcio F. M. Alves M. Fátima das G. F. Da Silva João B. Fernandes Paulo C. Vieira 《化学与生物多样性》2014,11(9):1354-1363
Cathepsins L (catL) and B play an important role in tumor progression and have been considered promising therapeutic targets in the development of novel anticancer agents. Using a bioactivity‐guided fractionation, a series of triterpenoids was identified as a new class of competitive inhibitors towards cathepsin L with affinity values in micromolar range. Among the 14 compounds evaluated, the most promising were 3‐epiursolic acid ( 3 ), 3‐(hydroxyimino)oleanolic acid ( 9 ), and 3‐(hydroxyimino)masticadienoic acid ( 13 ) with IC50 values of 6.5, 2.4, and 2.6 μM on catL, respectively. Most of the evaluated triterpenoids do not inhibit cathepsin B. Thus, the evaluated compounds exhibit a great potential to help in the design of new inhibitors with enhanced potency and affinity towards catL. Docking studies were performed in order to gain insight on the binding mode and SAR of these compounds. 相似文献
109.
Solá S Amaral JD Borralho PM Ramalho RM Castro RE Aranha MM Steer CJ Rodrigues CM 《Molecular endocrinology (Baltimore, Md.)》2006,20(10):2292-2303
Tauroursodeoxycholic acid (TUDCA) prevents amyloid beta-peptide (Abeta)-induced neuronal apoptosis, by modulating both classical mitochondrial pathways and specific upstream targets. In addition, activation of nuclear steroid receptors (NSRs), such as the mineralocorticoid receptor (MR) and the glucocorticoid receptor (GR) differentially regulates apoptosis in the brain. In this study we investigated whether TUDCA, a cholesterol-derived endogenous molecule, requires NSRs for inhibiting Abeta-induced apoptosis in primary neurons. Our results confirmed that TUDCA significantly reduced Abeta-induced apoptosis; in addition, the fluorescently labeled bile acid molecule was detected diffusely in both cytoplasm and nucleus of rat cortical neurons. Interestingly, experiments using small interfering RNAs (siRNAs) revealed that, in contrast to GR siRNA, MR siRNA abolished the antiapoptotic effect of TUDCA. Abeta incubation reduced MR nuclear translocation while increasing nuclear GR levels. Notably, pretreatment with TUDCA markedly altered Abeta-induced changes in NSRs, including MR dissociation from its cytosolic chaperone, heat shock protein 90, and subsequent translocation to the nucleus. Furthermore, when a carboxy terminus-deleted form of MR was used, nuclear trafficking of both MR and the bile acid was abrogated, suggesting that they translocate to the nucleus as a steroid-receptor complex. Transfection experiments with wild-type or mutant MR confirmed that this interaction was required for TUDCA protection against Abeta-induced apoptosis. Finally, in cotransfection experiments with NSR response element reporter and overexpression constructs, pretreatment with TUDCA significantly modulated Abeta-induced changes in MR and GR transactivation. In conclusion, these results provide novel insights into the specific cellular mechanism of TUDCA antiapoptotic function against Abeta-induced apoptosis and suggest targets for potential therapeutic intervention. 相似文献
110.
Fernandes FS Ramalho FS Nascimento JL Malaquias JB Nascimento AR Silva CA Zanuncio JC 《Bulletin of entomological research》2012,102(1):79-87
Knowledge of the vertical and horizontal distribution of Aphis gossypii Glover (Hemiptera: Aphididae) on genetically modified cotton plants over time could help optimize decision-making in integrated cotton aphid management programs. Therefore, the aim of the present study was to determine the vertical and horizontal distribution of A. gossypii in non-transgenic Bt cotton and transgenic Bt-cotton over time during two cotton seasons by examining plants throughout the seasons. There was no significant interaction between years and cotton cultivar treatments for apterous or alate aphids. Considering year-to-year data, analyses on season-long averages of apterous or alate aphids showed that aphid densities per plant did not differ among years. The number of apterous aphids found per plant for the Bt transgenic cultivar (2427 apterous aphids per plant) was lower than for its isoline (3335 apterous aphids per plant). The number of alate aphids found per plant on the Bt transgenic cultivar (12.28 alate aphids per plant) was lower than for the isoline (140.56 alate aphids per plant). With regard to the vertical distribution of apterous aphids or alate aphids, there were interactions between cotton cultivar, plant age and plant region. We conclude that in comparison to non-Bt cotton (DP 4049), Bt cotton (DP 404 BG (Bollgard)) has significant effects on the vertical, horizontal, spatial and temporal distribution patterns of A. gossypii, showing changes in its distribution behaviour inside the plant as the cotton crop develops. The results of our study are relevant for understanding the vertical and horizontal distribution of A. gossypii on Bt cotton cultivar (DP 404 BG (Bollgard)) and on its isoline (DP 4049), and could be useful in decision-making, implementing controls and determining the timing of population peaks of this insect. 相似文献