978 resultados para 14-3-3 Proteins


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Human RIN1 was first characterized as a RAS binding protein based on the properties of its carboxyl-terminal domain. We now show that full-length RIN1 interacts with activated RAS in mammalian cells and defines a minimum region of 434 aa required for efficient RAS binding. RIN1 interacts with the “effector domain” of RAS and employs some RAS determinants that are common to, and others that are distinct from, those required for the binding of RAF1, a known RAS effector. The same domain of RIN1 that binds RAS also interacts with 14-3-3 proteins, extending the similarity between RIN1 and other RAS effectors. When expressed in mammalian cells, the RAS binding domain of RIN1 can act as a dominant negative signal transduction blocker. The amino-terminal domain of RIN1 contains a proline-rich sequence similar to consensus Src homology 3 (SH3) binding regions. This RIN1 sequence shows preferential binding to the ABL–SH3 domain in vitro. Moreover, the amino-terminal domain of RIN1 directly associates with, and is tyrosine phosphorylated by, c-ABL. In addition, RIN1 encodes a functional SH2 domain that has the potential to activate downstream signals. These data suggest that RIN1 is able to mediate multiple signals. A differential pattern of expression and alternate splicing indicate several levels of RIN1 regulation.

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The proliferative compartment of stratified squamous epithelia consists of stem and transient amplifying (TA) keratinocytes. Some polypeptides are more abundant in putative epidermal stem cells than in TA cells, but no polypeptide confined to the stem cells has yet been identified. Here we show that the p63 transcription factor, a p53 homologue essential for regenerative proliferation in epithelial development, distinguishes human keratinocyte stem cells from their TA progeny. Within the cornea, nuclear p63 is expressed by the basal cells of the limbal epithelium, but not by TA cells covering the corneal surface. Human keratinocyte stem and TA cells when isolated in culture give rise to holoclones and paraclones, respectively. We show by clonal analysis that p63 is abundantly expressed by epidermal and limbal holoclones, but is undetectable in paraclones. TA keratinocytes, immediately after their withdrawal from the stem cell compartment (meroclones), have greatly reduced p63, even though they possess very appreciable proliferative capacity. Clonal evolution (i.e., generation of TA cells from precursor stem cells) is promoted by the sigma isoform of the 14-3-3 family of proteins. Keratinocytes whose 14-3-3σ has been down-regulated remain in the stem cell compartment and maintain p63 during serial cultivation. The identification of p63 as a keratinocyte stem cell marker will be of practical importance for the clinical application of epithelial cultures in cell therapy as well as for studies on epithelial tumorigenesis.

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It is generally accepted that globular proteins fold with a hydrophobic core and a hydrophilic exterior. Might the spatial distribution of amino acid hydrophobicity exhibit common features? The hydrophobic profile detailing this distribution from the protein interior to exterior has been examined for 30 relatively diverse structures obtained from the Protein Data Bank, for 3 proteins of the 30S ribosomal subunit, and for a simple set of 14 decoys. A second-order hydrophobic moment has provided a simple measure of the spatial variation. Shapes of the calculated spatial profiles of all native structures have been found to be comparable. Consequently, profile shapes as well as particular profile features should assist in validating predicted protein structures and in discriminating between different protein-folding pathways. The spatial profiles of the 14 decoys are clearly distinguished from the profiles of their native structures.

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The Bcl-2 protein blocks programmed cell death (apoptosis) through an unknown mechanism. Previously we identified a Bcl-2 interacting protein BAG-1 that enhances the anti-apoptotic effects of Bcl-2. Like BAG-1, the serine/threonine protein kinase Raf-1 also can functionally cooperate with Bcl-2 in suppressing apoptosis. Here we show that Raf-1 and BAG-1 specifically interact in vitro and in yeast two-hybrid assays. Raf-1 and BAG-1 can also be coimmunoprecipitated from mammalian cells and from insect cells infected with recombinant baculoviruses encoding these proteins. Furthermore, bacterially-produced BAG-1 protein can increase the kinase activity of Raf-1 in vitro. BAG-1 also activates this mammalian kinase in yeast. These observations suggest that the Bcl-2 binding protein BAG-1 joins Ras and 14-3-3 proteins as potential activators of the kinase Raf-1.

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Nos eucariotos, a evolução dos sistemas de transporte molecular foi essencial pois seu alto grau de compartimentalização requer mecanismos com maior especificidade para a localização de proteínas. Com o estabelecimento das mitocôndrias e plastídeos como organelas da célula eucariota, grande parte dos genes específicos para sua atividade e manutenção foram transferidos ao núcleo. Após a transferência gênica, a maioria das proteínas passaram a ser codificadas pelo núcleo, sintetizadas no citosol e direcionadas às organelas por uma maquinaria complexa que envolve receptores nas membranas das organelas, sequências de direcionamento nas proteínas e proteínas citossólicas que auxiliam o transporte. A importação depende em grande parte de uma sequência na região N-terminal das proteínas que contém sinais reconhecidos pelas membranas organelares. No entanto, muito ainda não é compreendido sobre o transporte de proteínas organelares e fatores ainda desconhecidos podem influenciar o direcionamento sub-celular. O objetivo deste trabalho foi a caracterização da General Regulatory Factor 9 (GRF9), uma proteína da família 14-3-3 de Arabidopsis thaliana potencialmente envolvida no direcionamento de proteínas organelares, e a geração de um genótipo para ser utilizado na obtenção de uma população mutante para genes que afetam o direcionamento da proteína Tiamina Monofosfato Sintetase (TH-1). Após experimentos in vivo e in planta, foi observado que GRF9 interage com as proteínas duplo-direcionadas Mercaptopyruvate Sulfurtransferase1 (MST1) e a Thiazole Biosynthetic Enzyme (THI1), e com a proteína direcionada aos cloroplastos TH-1. Experimentos de deleção e interação in vivo mostraram que a região Box1 de GRF9 é essencial para a interação com THI1 e MST1. Com a finalidade de dar continuidade a caracterização da GRF9 e para realização de testes com relação a sua função no direcionamento de proteínas organelares foi gerada uma linhagem homozigota que superexpressa GRF9. Plantas expressando o transgene TH-1 fusionado a Green Fluorescent Protein (GFP) em genótipo deficiente na TH-1 (CS3469/TH-1-GFP) foram obtidas para a geração de população mutante que possibilitará a descoberta de componentes genéticos ainda desconhecidos e responsáveis pelo direcionamento de proteínas aos cloroplastos.

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A composite record (LO09-14) of three sediment cores from the subpolar North Atlantic (Reykjanes Ridge) was investigated in order to assess surface ocean variability during the last 11 kyr. The core site is today partly under the influence of the Irminger Current (IC), a branch of the North Atlantic Drift continuing northwestward around Iceland. However, it is also proximal to the Sub-Arctic Front (SAF) that may cause extra dynamic hydrographic conditions. We used statistical methods applied to the fossil assemblages of diatoms to reconstruct quantitative sea surface temperatures (SSTs). Our investigations give evidence for different regional signatures of Holocene surface oceanographic changes in the North Atlantic. Core LO09-14 reveal relatively low and highly variable SSTs during the early Holocene, indicating a weak IC and increased advection of subpolar water over the site. A mid-Holocene thermal optimum with a strong IC occurs from 7.5 to 5 kyr and is followed by cooler and more stable late Holocene surface conditions. Several intervals throughout the Holocene are dominated by the diatom species Rhizosolenia borealis, which we suggest indicates proximity to a strongly defined convergence front, most likely the SAF. Several coolings, reflecting southeastward advection of cold and ice-bearing waters, occur at 10.4, 9.8, 8.3, 7.9, 6.4, 4.7, 4.3 and 2.8 kyr. The cooling events recorded in the LO09-14 SSTs correlate well with both other surface records from the area and the NADW reductions observed at ODP Site 980 indicating a surface-deepwater linkage through the Holocene.

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Although many of the molecular interactions in kidney development are now well understood, the molecules involved in the specification of the metanephric mesenchyme from surrounding intermediate mesoderm and, hence, the formation of the renal progenitor population are poorly characterized. In this study, cDNA microarrays were used to identify genes enriched in the murine embryonic day 10.5 (E10.5) uninduced metanephric mesenchyme, the renal progenitor population, in comparison with more rostral derivatives of the intermediate mesoderm. Microarray data were analyzed using R statistical software to determine accurately genes differentially expressed between these populations. Microarray outliers were biologically verified, and the spatial expression pattern of these genes at E10.5 and subsequent stages of early kidney development was determined by RNA in situ hybridization. This approach identified 21 genes preferentially expressed by the E10.5 metanephric mesenchyme, including Ewing sarcoma homolog, 14-3-3 theta, retinoic acid receptor-alpha, stearoyl-CoA desaturase 2, CD24, and cadherin-11, that may be important in formation of renal progenitor cells. Cell surface proteins such as CD24 and cadherin-11 that were strongly and specifically expressed in the uninduced metanephric mesenchyme and mark the renal progenitor population may prove useful in the purification of renal progenitor cells by FACS. These findings may assist in the isolation and characterization of potential renal stem cells for use in cellular therapies for kidney disease.

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A sediment core from Reykjanes Ridge has been studied at 10- to 50-year time resolution to document variability of Holocene surface water conditions in the western North Atlantic and to evaluate effects of Holocene ice-rafting episodes. Diatom assemblages are converted to quantitative sea surface temperatures (SST) using three different transfer functions. Spectral and scale-space methods are also applied on the records to explore variability at different timescales. Diatom assemblage and SST records clearly show that decaying remnants of the Laurentide ice sheet strongly influenced early Holocene climate in the western North Atlantic. This overrode the predominance of Milankovitch forcing, which played a key role in the development of Holocene climate in the eastern North Atlantic and Nordic Seas. Superimposed on general Holocene climate change is high-frequency SST variability on the order of 1°-3°C. The record also documents climatic oscillations with 600- to 1000-, ~1500-, and 2500-year periodicities, with a time-dependent dominance of different periodicities through the Holocene; a clear change in variability occurred about 5 ka BP. The SST record also provides evidence for Holocene cooling events (HCE) that, in some cases, correlate to documented southward intrusions of ice into the North Atlantic.

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Purpose. To determine the mechanisms predisposing penile fracture as well as the rate of long-term penile deformity and erectile and voiding functions. Methods. All fractures were repaired on an emergency basis via subcoronal incision and absorbable suture with simultaneous repair of eventual urethral lesion. Patients' status before fracture and voiding and erectile functions at long term were assessed by periodic follow-up and phone call. Detailed history included cause, symptoms, and single-question self-report of erectile and voiding functions. Results. Among the 44 suspicious cases, 42 (95.4%) were confirmed, mean age was 34.5 years (range: 18-60), mean follow-up 59.3 months (range 9-155). Half presented the classical triad of audible crack, detumescence, and pain. Heterosexual intercourse was the most common cause (28 patients, 66.7%), followed by penile manipulation (6 patients, 14.3%), and homosexual intercourse (4 patients, 9.5%). Woman on top was the most common heterosexual position (n = 14, 50%), followed by doggy style (n = 8, 28.6%). Four patients (9.5%) maintained the cause unclear. Six (14.3%) patients had urethral injury and two (4.8%) had erectile dysfunction, treated by penile prosthesis and PDE-5i. No patient showed urethral fistula, voiding deterioration, penile nodule/curve or pain. Conclusions. Woman on top was the potentially riskiest sexual position (50%). Immediate surgical treatment warrants long-term very low morbidity.

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BACKGROUND: Strictureplasty is an alternative surgical procedure for Crohn?s disease, particulary in patients with previous resections or many intestinal stenosis. AIM: To analyze surgical complications and clinical follow-up in patients submitted to strictureplasty secondary to Crohn?s disease. METHODS: Twenty-eight patients (57.1% male, mean age 33.3 years, range 16-54 years) with Crohn?s disease and intestinal stenosis (small bowel, ileocecal region and ileocolic anastomosis) were submitted to strictureplasty, at one institution, between September 1991 and May 2004. Thirteen patients had previous intestinal resections. The mean follow-up was 58.1 months. A total of 116 strictureplasties were done (94 Heineke-Mikulicz - 81%, 15 Finney - 13%, seven side-to-side ileocolic strictureplasty - 6%). Three patients were submitted to strictureplasty at two different surgical procedures and two in three procedures. RESULTS: Regarding to strictureplasty, postoperative complication rate was 25% and mortality was 3.6%. Early local complication rate was 57.1%, with three suture leaks (10.7%) and late complication was present in two patients, both with incisional hernial and enterocutaneous fistulas (28.6%). Patients remained hospitalized during a medium time of 12.4 days. Clinical and surgical recurrence rates were 63% and 41%, respectively. Among the patients submitted to another surgery, two patients had two more operations and one had three. Recurrence rate at strictureplasty site was observed in 3.5%, being Finney technique the commonest one. Presently, 19 patients had been asymptomatic with the majority of them under medical therapy. CONCLUSION: Strictureplasties have low complication rates, in spite of having been done at compromised site, with long term pain relief. Considering the clinical course of Crohn?s disease, with many patients being submitted to intestinal resections, strictureplasties should be considered as an effective surgical treatment to spare long intestinal resections.

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Alginate microparticles were prepared by an emulsion method aiming oral controlled release of antigens to fish. The effects of emulsification temperature and impeller type on particle morphology, average diameter, and size distribution were evaluated. Microparticles contaning formalin-killed Flavobacterium columnare cells (a model antigen) were prepared and characterized regarding bacterial release and particle stability when exposed to Nile tilapia (Oreochromis niloticus) typical gastrointestinal conditions. This methodology allowed the production of microparticles containing up to 14.3 g/L of bacterin, stable at a pH range from 2.0 to 9.0 for 12 h and smaller than 35 μm.

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Purpose: To identify improvement in visual performance of low vision students after assessment and management conducted at the Low Vision Service of State University of Campinas (UNICAMP). Method: Fourteen low vision students aged six to 30 years, attended in a room with resources for visual deficiency in Americana and Santa Bárbara d'Oeste -- SP during 1998 received complete ophthalmologic examination, specialized low vision assessment and educational intervention. Results: The most prevalent cause of vision loss was operated congenital cataract with four cases (28.6%), followed by congenital bilateral toxoplasmic macular scars and eye malformation, both with two cases (14.3%) cases each. Eight students (57.2%) had acuity classified as severe vision loss, four (28.6%) profound, one (7.1%) moderate and one (7.1%) nearly normal vision. Twelve (85.7%) were behind expected school grade. Optical aids were prescribed for 12 (85.8%) students but only 7 (58.3%) acquired the aids thus improving significantly their school performance. Conclusion: All students improved school performance even considering that 12 (85.7%) had severe to profound vision loss. As a group their performance could even be better if the optical aid prescriptions were acquired by all. This indicates the need of a social work to support such needs. For good results at school and effective student inclusion a partnership between school, family and specialized education is necessary. We recommend to promote the benefits of the resource room.

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Universidade Estadual de Campinas . Faculdade de Educação Física

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FUNDAMENTO: A doença periodontal representa risco à gestante portadora de valvopatia reumática, seja para contrair endocardite infecciosa, seja por propiciar complicações obstétricas. OBJETIVO: Estudar a frequência da doença periodontal em portadoras de valvopatia reumática durante a gravidez. MÉTODOS: Foram estudadas 140 gestantes, comparáveis quanto a idade e o nível socioeconômico, divididas em: 70 portadoras de doença valvar reumática e 70 mulheres saudáveis. Todas se submeteram a: 1) avaliação clínica odontológica que incluiu a análise dos seguintes parâmetros: 1.1) profundidade à sondagem, 1.2) distância da linha esmalte-cemento à margem gengival, 1.3) nível clínico de inserção, 1.4) índice de sangramento, 1.5) índice de placa bacteriana, e, 1.6) comprometimento de furca; e, 2) exame microbiológico nas amostras de saliva e do cone que considerou o controle positivo para as cepas das bactérias Porphyromonas gingivalis, Tannerella forsithia e Aggregobacter actinomycetemcomitans. RESULTADOS: A lesão valvar mitral foi prevalente (65 casos = 92,8%) dentre as gestantes cardiopatas. A comparação entre os grupos mostrou não haver diferenças entre idade e a paridade, e embora tenham sido verificadas diferenças entre as medidas da distância da linha esmalte-cemento à margem gengival (p = 0,01) e o índice de placa (p=0,04), a frequência da doença periodontal identificada em 20 (14,3%) gestantes, não foi diferente entre os grupos (p = 0,147). O exame microbiológico mostrou uma proporção maior da bactéria P. gingivalis na saliva de gestantes saudáveis (p = 0,004). CONCLUSÃO: O estudo clínico e microbiológico periodontal durante a gravidez demonstrou igual frequência da doença periodontal em portadoras de valvopatia reumática quando comparada às mulheres saudáveis.

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The objective of the present study was to evaluate the occurrence of Staphylococcus aureus in milk produced in 37 farms located in the regions of Ribeirão Preto and São Carlos, state of São Paulo, Brazil. Two-hundred and eight samples of milk from individual cows showing subclinical mastitis, and 37 samples of bulk tank milk were analyzed. S. aureus strains were detected in 18 (7.3%) milk samples: 14 (6.7%) from samples of individual cows, and 4 (10.8%) from bulk tank milk. Two individual milk samples (14.3%) and two bulk milk samples contained enterotoxigenic S. aureus. PFGE analysis revealed the genetic heterogeneity of the strains isolated from raw milk, which presented to 13 S. aureus patterns. Results confirmed the potential transmission of staphylococcal food poisoning to consumers via milk of cows affected by subclinical mastitis, mainly when raw milk is ingested.