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1.
Desiree?M?Baron Laura?J?Kaushansky Catherine?L?Ward Reddy?Ranjith?K?Sama Ru-Ju?Chian Kristin?J?Boggio Alexandre?J?C?Quaresma Jeffrey?A?Nickerson Daryl?A?BoscoEmail author 《Molecular neurodegeneration》2013,8(1):30
Background
Amyotrophic lateral sclerosis (ALS)-linked fused in sarcoma/translocated in liposarcoma (FUS/TLS or FUS) is concentrated within cytoplasmic stress granules under conditions of induced stress. Since only the mutants, but not the endogenous wild-type FUS, are associated with stress granules under most of the stress conditions reported to date, the relationship between FUS and stress granules represents a mutant-specific phenotype and thus may be of significance in mutant-induced pathogenesis. While the association of mutant-FUS with stress granules is well established, the effect of the mutant protein on stress granules has not been examined. Here we investigated the effect of mutant-FUS on stress granule formation and dynamics under conditions of oxidative stress.Results
We found that expression of mutant-FUS delays the assembly of stress granules. However, once stress granules containing mutant-FUS are formed, they are more dynamic, larger and more abundant compared to stress granules lacking FUS. Once stress is removed, stress granules disassemble more rapidly in cells expressing mutant-FUS. These effects directly correlate with the degree of mutant-FUS cytoplasmic localization, which is induced by mutations in the nuclear localization signal of the protein. We also determine that the RGG domains within FUS play a key role in its association to stress granules. While there has been speculation that arginine methylation within these RGG domains modulates the incorporation of FUS into stress granules, our results demonstrate that this post-translational modification is not involved.Conclusions
Our results indicate that mutant-FUS alters the dynamic properties of stress granules, which is consistent with a gain-of-toxic mechanism for mutant-FUS in stress granule assembly and cellular stress response.2.
Quaresma AJ Oyama S Barbosa JA Kobarg J 《Biochemical and biophysical research communications》2006,350(2):288-297
Apobec1 edits the ApoB mRNA by deaminating nucleotide C(6666), which results in a codon change from Glutamate to stop, and subsequent expression of a truncated protein. Apobec1 is regulated by ACF (Apobec1 complementation factor) and hnRNPQ, which contains an N-terminal "acidic domain" (AcD) of unknown function, three RNA recognition motifs, and an Arg/Gly-rich region. Here, we modeled the structure of AcD using the bacterial protein Barstar as a template. Furthermore, we demonstrated by in vitro pull-down assays that 6xHis-AcD alone is able to interact with GST-Apobec1. Finally, we performed in silico phosphorylation of AcD and molecular dynamics studies, which indicate conformational changes in the phosphorylated form. The results of the latter studies were confirmed by in vitro phosphorylation of 6xHis-AcD by protein kinase C, mass spectrometry, and spectroscopic analyses. Our data suggest hnRNPQ interactions via its AcD with Apobec1 and that this interaction is regulated by the AcD phosphorylation. 相似文献
3.
DF Henriques JA Quaresma HT Fuzii MR Nunes EV Silva VL Carvalho LC Martins SM Casseb JO Chiang PF Vasconcelos 《Memórias do Instituto Oswaldo Cruz》2012,107(5):630-636
Rocio virus (ROCV) is an encephalitic flavivirus endemic to Brazil. Experimental flavivirus infections have previously demonstrated a persistent infection and, in this study, we investigated the persistence of ROCV infection in golden hamsters (Mesocricetus auratus). The hamsters were infected intraperitoneally with 9.8 LD50/0.02 mL of ROCV and later anaesthetised and sacrificed at various time points over a 120-day period to collect of blood, urine and organ samples. The viral titres were quantified by real-time-polymerase chain reaction (qRT-PCR). The specimens were used to infect Vero cells and ROCV antigens in the cells were detected by immunefluorescence assay. The levels of antibodies were determined by the haemagglutination inhibition technique. A histopathological examination was performed on the tissues by staining with haematoxylin-eosin and detecting viral antigens by immunohistochemistry (IHC). ROCV induced a strong immune response and was pathogenic in hamsters through neuroinvasion. ROCV was recovered from Vero cells exposed to samples from the viscera, brain, blood, serum and urine and was detected by qRT-PCR in the brain, liver and blood for three months after infection. ROCV induced histopathological changes and the expression of viral antigens, which were detected by IHC in the liver, kidney, lung and brain up to four months after infection. These findings show that ROCV is pathogenic to golden hamsters and has the capacity to cause persistent infection in animals after intraperitoneal infection. 相似文献
4.
Ana Cravo Sá Ana Fermento Dalila Neves Sara Ferreira Teresa Silva Carina Marques Coelho Aude Vaandering Ana Roma Sérgio Quaresma Emmanuel Bonnarens 《Reports of Practical Oncology and Radiotherapy》2018,23(1):61-67
Aim
In this study, we intend to compare two different setup procedures for female breast cancer patients.Background
Imaging in radiotherapy provides a precise localization of the tumour, increasing the accuracy of the treatment delivery in breast cancer.Materials and methods
Twenty breast cancer patients who underwent whole breast radiotherapy (WBRT) were selected for this study. Patients were divided into two groups of ten. Group one (G1) was positioned by tattoos and then the patient positioning was adjusted with the aid of AlignRT (Vision RT, London, UK). In group two (G2), patients were positioned only by tattoos. For both groups, the first 15 fractions were analyzed, a daily kilovoltage (kV) cone beam computed tomography (CBCT) image was made and then the rotational and translational displacements and, posteriorly, the systematic (Σ) and random (σ) errors were analyzed.Results
The comparison of CBCT displacements for the two groups showed a statistically significant difference in the translational left–right (LR) direction (ρ = 0.03), considering that the procedure with AlignRT system has smaller lateral displacements. The results of systematic (Σ) and random (σ) errors showed that for translational displacements the group positioned only by tattoos (G2) demonstrated higher values of errors when compared with the group positioned with the aid of AlignRT (G1).Conclusions
AlignRT could help the positioning of breast cancer patients; however, it should be used with another imaging method. 相似文献5.
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Adriano C. Quaresma Maria Teresa F. Piedade Florian Wittmann Hans ter Steege 《Biodiversity and Conservation》2018,27(8):1981-2002
This study examines the occurrence of vascular epiphytic species in Central Amazonian black-water floodplain forests (igapó) and considers whether their horizontal and vertical distribution is influenced by the flood pulse, as is the case with tree species (phorophytes). Research was conducted in sixteen forest plots the Jaú National Park. In these, epiphytes on all phorophytes with DBH ≥ 10 cm were identified. We measured flood height using the watermark left by the last high-water period, then estimated the height relative to the ground of every epiphytic individual. We recorded 653 individuals in 37 species, distributed on 109 phorophytes. Igapó floodplain forests have much lower richness and abundance of vascular epiphyte species than do other Amazonian forests. This may reflect the limitation of available sites for colonization (only 24.9% of studied trees were occupied by epiphytes). Holoepiphytes predominated, and the combined presence of a flood-pulse, linked to the nutrient-poor soil poor seems to limit the occurrence of nomadic vines. Horizontal distribution of epiphytes followed the distribution of phorophytes, which in turn followed the flood-level gradient. Also flooding interacted strongly with vertical zonation to determine species richness. As already well-reported for trees, and unlike reports of epiphytes in other floodplains, flooding strongly influenced richness and distribution of vascular epiphytes in the studied igapó forests. 相似文献
8.
Alexandre J.C. Quaresma L.M. Gava D.C.F. Lanza C.H.I Ramos 《Experimental cell research》2009,315(6):968-6206
Eukaryotic gene expression is regulated on different levels ranging from pre-mRNA processing to translation. One of the most characterized families of RNA-binding proteins is the group of hnRNPs: heterogenous nuclear ribonucleoproteins. Members of this protein family play important roles in gene expression control and mRNAs metabolism. In the cytoplasm, several hnRNPs proteins are involved in RNA-related processes and they can be frequently found in two specialized structures, known as GW-bodies (GWbs), previously known as processing bodies: PBs, and stress granules, which may be formed in response to specific stimuli. GWbs have been early reported to be involved in the mRNA decay process, acting as a site of mRNA degradation. In a similar way, stress granules (SGs) have been described as cytoplasmic aggregates, which contain accumulated mRNAs in cells under stress conditions and present reduced or inhibited translation. Here, we characterized the hnRNP Q localization after different stress conditions. hnRNP Q is a predominantly nuclear protein that exhibits a modular organization and several RNA-related functions. Our data suggest that the nuclear localization of hnRNP Q might be modified after different treatments, such as: PMA, thapsigargin, arsenite and heat shock. Under different stress conditions, hnRNP Q can fully co-localize with the endoplasmatic reticulum specific chaperone, BiP. However, under stress, this protein only co-localizes partially with the proteins: GW182 — GWbs marker protein and TIA-1 stress granule component. 相似文献
9.
Patrícia K.S. Ramos José A.P. Diniz Edilene O. Silva Juarez A.S. Quaresma Elvira M. Saraiva Sérgio H. Seabra Geórgia C. Atella Wanderley de Souza 《Parasitology international》2009,58(2):154-160
The present study analyses complement resistance, cell surface carbohydrates expression, lipidic composition and morphology in vivo and in vitro, of Leishmania (Viannia) shawi, a parasite identified in the Amazon region, Pará state, in 1989. We demonstrated that promastigotes in the stationary (STAT) growth phase are more resistant to complement lysis than in the logarithimic (LOG) growth phase. Ultrastructural analyses and imidazol technique showed accumulation of lipids in STAT growth phase promastigotes, which was confirmed by biochemical approach. Light and electron microscopy of skin lesion in hamster footpads caused by promastigotes in STAT growth phase, 90 days post inoculation, showed amastigotes inside of macrophage and free in the tissue surrounded by collagen fibers as well as extensive inflammatory reaction with tissue destruction. We also demonstrated, using lectins by agglutination assays and flow cytometry, the presence of fucose, mannose and/or glucose carbohydrate residues on the surface of LOG and STAT promastigotes. The results constitute the first characterization essay combining biochemical and morphological approaches dedicated to LOG and STAT growth phase promastigotes of L. (V) shawi contributing for a better knowledge of this poorly studied species of the New World. 相似文献
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