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1.
Holist Nurs Pract ; 37(1): 15-23, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36378088

RESUMO

Although the practice of forgiveness is encouraged, the healing properties of this virtue by health care professionals are often overlooked. Forgiveness is the voluntary, conscious decision to abandon negative feelings toward another who has caused hurt and replacing those feelings with unconditional love and compassion. It is not about forgetting the hurt or ignoring the pain; it is an actual transformation of the heart. The Enright Forgiveness Process Model and the Pyramid Model of Forgiveness are 2 models that facilitate the forgiveness process. By utilizing either of these pathways, the forgiver ultimately experiences peace of mind and a "release from emotional prison" that leads to holistic healing. As a result, the forgiver experiences lower levels of depression, anxiety, and aggression, which improves quality of life. In addition, physiological benefits such as decreased stress levels, lower blood pressure, and a lower heart rate have also been reported. Throughout the course of their careers, nurses encounter patients and families in acute or end-of-life care situations who want to forgive or be forgiven. As holistic health care providers, nurses should be able to facilitate and close this gap in patient care. This article attempts to raise awareness to the importance of forgiveness in health and well-being among nurses and other health care professionals.


Assuntos
Perdão , Assistência Terminal , Humanos , Qualidade de Vida , Emoções
2.
J Holist Nurs ; 40(4): 336-350, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35006022

RESUMO

Purpose of study: The need for forgiveness education for nursing self-care and forgiveness facilitation has risen. Therefore, the present pilot study tested the efficacy of an 8-week forgiveness bibliotherapy with a small number of undergraduate nursing students. Design of study: Matched pairs of nursing students were randomly assigned to either the experimental group or no-contact control group. The experimental group, using 8 keys to forgiveness by R. Enright (2015) as the treatment manual, read one chapter a week for 8 weeks and provided weekly reflections. Forgiveness and forgiveness-related outcome measures were administered at pretest, posttest, and one-month follow-up. Findings: At the posttest, the experimental group had significantly greater improvement in forgiveness compared to the control group with a large effect size, which was maintained at one month follow-up. There was no other significant difference between the two groups. Within-group comparisons of the experimental group showed improvement in forgiveness, anxiety, depression, and fatigue from pre to post testing periods and forgiveness, anger, anxiety, depression, and fatigue from pre to follow-up testing periods. Conclusion: Use of bibliotherapy may be a cost-effective way to promote the virtue of forgiveness for students in nursing programs.


Assuntos
Biblioterapia , Bacharelado em Enfermagem , Perdão , Estudantes de Enfermagem , Humanos , Projetos Piloto , Fadiga
3.
Trop Life Sci Res ; 32(2): 121-132, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34367518

RESUMO

Scale structure and reflectance activity of a Mindanao endemic weevil from the genus Metapocyrtus has been studied for the first time. Specimens of Metapocyrtus apoensis Schultze, 1925 were collected through opportunistic sampling in Mount Calayo, Musuan, Mindanao, Philippines last February 2020. A total of three individuals of the species were collected all in lower dipterocarp forest with elevation of 500 masl-600 masl. Three specimens were then examined under Scanning Electron Microscopy with Energy Dispersive X-Ray (SEM_EDX) to analyse its scale structures and reflectance activity. The study provides new locality record of the Mindanao endemic species first in Bukidnon region and an updated distribution in Mindanao based on recent published articles and museum collections. The species inhabits wide ranges of habitat types that greatly differ in elevation and vegetation. Examination of scale's structure through SEM revealed that M. apoensis scales are 50 µm-70 µm in diameter which are almost circular in shape, slightly convex with rough like surface which is termed as non-ordered nipple-like structure. The scales' shape and surface structure clearly differ from other genera of curculionids based on published articles. Analysis of the particles on the weevil's elytra done by EDX reveals several elements that contribute to its iridescence. Major elements such as carbon (42.3%), oxygen (27.7%) and nitrogen (15.1%) come in relatively high atomic concentrations. Microspectrometer revealed a peak reflectance wavelength of about 569.7 nm. This explains the yellow-green iridescence observed on the dorsal side of the weevil. The concentration of the scale in pits serves for protection, intraspecific recognition and camouflage. Despite of widespread distribution and high abundance of this species in Mindanao, anthropogenic disturbances such as agricultural activities are on-going which extend towards their microhabitat. Monitoring to its population is recommended as the species is restricted only in Mindanao.

4.
ISA Trans ; 95: 358-371, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31171304

RESUMO

The safety and public health during nuclear power plant operation can be enhanced by accurately recognizing and diagnosing potential problems when a malfunction occurs. However, there are still obvious technological gaps in fault diagnosis applications, mainly because adopting a single fault diagnosis method may reduce fault diagnosis accuracy. In addition, some of the proposed solutions rely heavily on fault examples, which cannot fully cover future possible fault modes in nuclear plant operation. This paper presents the results of a research in hybrid fault diagnosis techniques that utilizes support vector machine (SVM) and improved particle swarm optimization (PSO) to perform further diagnosis on the basis of qualitative reasoning by knowledge-based preliminary diagnosis and sample data provided by an on-line simulation model. Further, SVM has relatively good classification ability with small samples compared to other machine learning methodologies. However, there are some challenges in the selection of hyper-parameters in SVM that warrants the adoption of intelligent optimization algorithms. Hence, the major contribution of this paper is to propose a hybrid fault diagnosis method with a comprehensive and reasonable design. Also, improved PSO combined with a variety of search strategies are achieved and compared with other current optimization algorithms. Simulation tests are used to verify the accuracy and interpretability of research findings presented in this paper, which would be beneficial for intelligent execution of nuclear power plant operation.


Assuntos
Análise de Falha de Equipamento , Centrais Nucleares , Material Particulado , Máquina de Vetores de Suporte , Algoritmos , Simulação por Computador , Sistemas On-Line
5.
Oncogene ; 35(16): 2020-30, 2016 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-26189795

RESUMO

Current treatment regimens for rhabdomyosarcoma (RMS), the most common pediatric soft tissue cancer, rely on conventional chemotherapy, and although they show clinical benefit, there is a significant risk of adverse side effects and secondary tumors later in life. Therefore, identifying and targeting sub-populations with higher tumorigenic potential and self-renewing capacity would offer improved patient management strategies. Hedgehog signaling has been linked to the development of embryonal RMS (ERMS) through mouse genetics and rare human syndromes. However, activating mutations in this pathway in sporadic RMS are rare and therefore the contribution of hedgehog signaling to oncogenesis remains unclear. Here, we show by genetic loss- and gain-of-function experiments and the use of clinically relevant small molecule modulators that hedgehog signaling is important for controlling self-renewal of a subpopulation of RMS cells in vitro and tumor initiation in vivo. In addition, hedgehog activity altered chemoresistance, motility and differentiation status. The core stem cell gene NANOG was determined to be important for ERMS self-renewal, possibly acting downstream of hedgehog signaling. Crucially, evaluating the presence of a subpopulation of tumor-propagating cells in patient biopsies identified by GLI1 and NANOG expression had prognostic significance. Hence, this work identifies novel functional aspects of hedgehog signaling in ERMS, redefines the rationale for its targeting as means to control ERMS self-renewal and underscores the importance of studying functional tumor heterogeneity in pediatric cancers.


Assuntos
Carcinogênese , Proteínas Hedgehog/metabolismo , Rabdomiossarcoma Embrionário/patologia , Transdução de Sinais , Humanos , Prognóstico , Rabdomiossarcoma Embrionário/metabolismo , Células Tumorais Cultivadas
6.
IEEE Trans Cybern ; 44(8): 1420-31, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25051452

RESUMO

Multichannel sensor systems are widely used in condition monitoring for effective failure prevention of critical equipment or processes. However, loss of sensor readings due to malfunctions of sensors and/or communication has long been a hurdle to reliable operations of such integrated systems. Moreover, asynchronous data sampling and/or limited data transmission are usually seen in multiple sensor channels. To reliably perform fault diagnosis and prognosis in such operating environments, a data recovery method based on functional principal component analysis (FPCA) can be utilized. However, traditional FPCA methods are not robust to outliers and their capabilities are limited in recovering signals with strongly skewed distributions (i.e., lack of symmetry). This paper provides a robust data-recovery method based on functional data analysis to enhance the reliability of multichannel sensor systems. The method not only considers the possibly skewed distribution of each channel of signal trajectories, but is also capable of recovering missing data for both individual and correlated sensor channels with asynchronous data that may be sparse as well. In particular, grand median functions, rather than classical grand mean functions, are utilized for robust smoothing of sensor signals. Furthermore, the relationship between the functional scores of two correlated signals is modeled using multivariate functional regression to enhance the overall data-recovery capability. An experimental flow-control loop that mimics the operation of coolant-flow loop in a multimodular integral pressurized water reactor is used to demonstrate the effectiveness and adaptability of the proposed data-recovery method. The computational results illustrate that the proposed method is robust to outliers and more capable than the existing FPCA-based method in terms of the accuracy in recovering strongly skewed signals. In addition, turbofan engine data are also analyzed to verify the capability of the proposed method in recovering non-skewed signals.

7.
ISA Trans ; 53(2): 568-77, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24411932

RESUMO

A two-tank multivariate loop was designed and built to support research related to instrumentation and control, equipment and sensor monitoring. This test bed provides the framework necessary to investigate and test control strategies and fault detection methods applicable to sensors, equipment, and actuators, and was used to experimentally develop and demonstrate a fault-tolerant control strategy using six correlated variables in a single-tank configuration. This work shows the feasibility of using data-based empirical models to perform fault detection and substitute faulty measurements with predictions and to perform control reconfiguration in the presence of actuator failure in a real system. These experiments were particularly important because they offered the opportunity to prove that a system, such as the multivariate control loop, could survive degraded conditions, provided the empirical models used were accurate and representative of the process dynamics.

9.
Mol Plant ; 2(4): 654-660, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19825646

RESUMO

Genomic imprinting is an epigenetic phenomenon that causes monoallelic expression of specific genes dependent on the parent-of-origin. Imprinting of the Arabidopsis gene PHERES1 requires the function of the FERTILIZATION INDEPENDENT SEED (FIS) Polycomb group complex as well as a distally located methylated region containing a tandem triple repeat sequence. In this study, we investigated the regulation of the close PHERES1 homolog PHERES2. We found that PHERES2 is also a direct target gene of the FIS Polycomb group complex, but, in contrast to PHERES1, PHERES2 is equally expressed from maternal and paternal alleles. Thus, PHERES2 is not regulated by genomic imprinting, correlating with the lack of tandem repeats at PHERES2. Eliminating tandem repeats from the PHERES1 locus abolishes PHERES1 imprinting, demonstrating that tandem repeats are essential for PHERES1 imprinting. Taking these results together, our study shows that the recently duplicated genes PHERES1 and PHERES2 are both target genes of the FIS Polycomb group complex but only PHERES1 is regulated by genomic imprinting, which is likely caused by the presence of repeat sequences in the proximity of the PHERES1 locus.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Impressão Genômica/genética , Proteínas de Domínio MADS/genética , Plantas Geneticamente Modificadas/genética , Sequências de Repetição em Tandem/genética , Alelos , Montagem e Desmontagem da Cromatina/genética , Imunoprecipitação da Cromatina , Epigênese Genética/genética , Regulação da Expressão Gênica de Plantas/genética , Reação em Cadeia da Polimerase
10.
ISA Trans ; 48(2): 213-9, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19084227

RESUMO

This paper presents an incipient fault diagnosis approach based on the Group Method of Data Handling (GMDH) technique. The GMDH algorithm provides a generic framework for characterizing the interrelationships among a set of process variables of fossil power plant sub-systems and is employed to generate estimates of important variables in a data-driven fashion. In this paper, ridge regression techniques are incorporated into the ordinary least squares (OLS) estimator to solve regression coefficients at each layer of the GMDH network. The fault diagnosis method is applied to feedwater heater leak detection with data from an operating coal-fired plant. The results demonstrate the proposed method is capable of providing an early warning to operators when a process fault or an equipment fault occurs in a fossil power plant.


Assuntos
Algoritmos , Análise de Falha de Equipamento/métodos , Retroalimentação , Combustíveis Fósseis , Modelos Teóricos , Centrais Elétricas , Simulação por Computador , Análise Numérica Assistida por Computador
11.
Dis Aquat Organ ; 77(3): 175-9, 2007 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-18062468

RESUMO

Prevalence of white spot syndrome virus (WSSV) was determined using polymerase chain reaction (PCR) methodology on DNA extracted from the gills of wild black tiger shrimp Penaeus monodon collected from 7 sampling sites in the Philippines. These 7 sampling sites are the primary sources of spawners and broodstock for hatchery use. During the dry season, WSSV was detected in shrimp from all sites except Bohol, but during the wet season it was not detected in any site except Palawan. None of the WSSV-PCR positive shrimp showed signs of white spots in the cuticle. Prevalence of WSSV showed seasonal variations, i.e. prevalence in dry season (April to May) was higher than in the wet season (August to October). These results suggest that WSSV has already become established in the local marine environment and in wild populations of P. monodon. Thus, broodstock collected during the dry season could serve as the main source of WSSV contamination in shrimp farms due to vertical transmission of the virus in hatcheries.


Assuntos
Penaeidae/virologia , Vírus da Síndrome da Mancha Branca 1/patogenicidade , Animais , Animais Selvagens , DNA Viral/isolamento & purificação , Feminino , Brânquias/virologia , Masculino , Filipinas/epidemiologia , Reação em Cadeia da Polimerase/veterinária , Prevalência , Estações do Ano , Vírus da Síndrome da Mancha Branca 1/genética
12.
Cell Mol Life Sci ; 64(13): 1723-34, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17497240

RESUMO

DNA integrity checkpoint control was studied in the sea urchin early embryo. Treatment of the embryos with genotoxic agents such as methyl methanesulfonate (MMS) or bleomycin induced the activation of a cell cycle checkpoint as evidenced by the occurrence of a delay or an arrest in the division of the embryos and an inhibition of CDK1/cyclin B activating dephosphorylation. The genotoxic treatment was shown to induce DNA damage that depended on the genotoxic concentration and was correlated with the observed cell cycle delay. At low genotoxic concentrations, embryos were able to repair the DNA damage and recover from checkpoint arrest, whereas at high doses they underwent morphological and biochemical changes characteristic of apoptosis. Finally, extracts prepared from embryos were found to be capable of supporting DNA repair in vitro upon incubation with oligonucleotides mimicking damage. Taken together, our results demonstrate that sea urchin early embryos contain fully functional and activatable DNA damage checkpoints. Sea urchin embryos are discussed as a promising model to study the signaling pathways of cell cycle checkpoint, DNA repair and apoptosis, which upon deregulation play a significant role in the origin of cancer.


Assuntos
Apoptose , Dano ao DNA , Reparo do DNA , Embrião não Mamífero/metabolismo , Ouriços-do-Mar/embriologia , Ouriços-do-Mar/metabolismo , Transdução de Sinais , Animais , Apoptose/efeitos dos fármacos , Proteína Quinase CDC2/metabolismo , Caspases/metabolismo , Divisão Celular/efeitos dos fármacos , Ciclina B/metabolismo , Reparo do DNA/efeitos dos fármacos , Embrião não Mamífero/citologia , Embrião não Mamífero/efeitos dos fármacos , Embrião não Mamífero/enzimologia , Ativação Enzimática/efeitos dos fármacos , Cinética , Modelos Biológicos , Mutagênicos/farmacologia , Ouriços-do-Mar/citologia , Ouriços-do-Mar/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
13.
Cell Mol Life Sci ; 60(10): 2178-88, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14618264

RESUMO

Eukaryotic elongation factor 1 (eEF1) is a translational multimolecular complex reported in higher eukaryotes to be a target of CDK1/cyclin B, the universal regulator of M phase, but whose role in the cell cycle remains to be determined. A specific polyclonal antibody was produced and used to characterize the delta subunit of sea urchin elongation factor 1 (SgEF1delta) in early embryos, a powerful model for investigating cell cycle regulation. The SgEF1delta protein was present in unfertilized eggs as two isoforms of 35 and 37 kDa, issued from two different mRNAs. The two canonical eEF1delta partners, eEF1gamma and eEF1beta, were shown to co-immunoprecipitate with the SgEF1delta isoforms. Both isoforms were associated in a macromolecular complex, which resolved upon gel filtration chromatography at a molecular weight > 400 kDa, suggesting association with other yet unidentified partners. After fertilization, the amount as well as the ratio of both SgEF1delta isoforms remained constant during the first cell division as judged by Western blotting. Immunofluorescence analysis showed that a pool of the protein concentrated as a ring at the embryo nuclear location around the period of nuclear envelope breakdown and was visualized later as two large spheres around the mitotic spindle poles. Thus, the eEF1delta protein shows cell cycle-specific localization changes in sea urchin embryos.


Assuntos
Fator 1 de Elongação de Peptídeos/metabolismo , Ouriços-do-Mar/metabolismo , Sequência de Aminoácidos , Animais , Ciclo Celular/fisiologia , Mitose/fisiologia , Dados de Sequência Molecular , Fator 1 de Elongação de Peptídeos/imunologia , Transporte Proteico/fisiologia , Ouriços-do-Mar/embriologia , Ouriços-do-Mar/imunologia , Tubulina (Proteína)/metabolismo
14.
Zygote ; 9(3): 229-36, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11508742

RESUMO

Protein synthesis was analysed following fertilisation in sea urchin. Fluctuations in the accumulation of neo-synthesised proteins were observed during the first cell cycles. Accurate translation analyses were performed from lysates prepared from early embryos. The lysates readily translated endogenous pre-initiated mRNAs allowing the determination of elongation rates in the absence of re-initiation in vitro. The translation capacity of embryo lysates increased 18-fold from 0 to 90 min after fertilisation, reflecting the increase in the amount of pre-initiated mRNAs during early development. Kinetics analysis at a short time interval during the course of early development (240 min) showed an overall increase in the elongation rate (> 10-fold) which is regulated by pauses in synchrony with the cell divisions. Elongation activity in the lysates was highly sensitive to the natural polyamines, spermine (ID50 = 0.2 mM) and spermidine (ID50 = 1.8 mM), indicating high potential regulation by the intracellular level of polyamines in embryos. The regulation in the elongation changes associated with the early embryo cell divisions is discussed in the light of the physiological fluctuations in polyamine concentrations.


Assuntos
Divisão Celular , Embrião não Mamífero/metabolismo , Peptídeos/metabolismo , Poliaminas/metabolismo , Biossíntese de Proteínas , Animais , Sistema Livre de Células , Relação Dose-Resposta a Droga , Fertilização , Fertilização in vitro , Cinética , Poliaminas/farmacologia , Proteínas Quinases/metabolismo , RNA/metabolismo , RNA Mensageiro/metabolismo , Ouriços-do-Mar , Espermidina/farmacologia , Espermina/farmacologia , Fatores de Tempo
15.
Dev Biol ; 232(2): 275-83, 2001 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-11401391

RESUMO

The eukaryotic translation initiation factor (eIF) 4F facilitates the recruitment of ribosomes to the mRNA 5' end. The 4E-BPs are small proteins with hypophosphorylated forms that interact with the cap binding protein eIF4E, preventing its interaction with eIF4G, thereby preventing ribosome interaction with mRNA. In sea urchin, fertilization triggers a rapid rise in protein synthesis. Here, we demonstrate that a 4E-BP homologue exists and is associated with eIF4E in unfertilized eggs. We also show that 4E-BP/eIF4E association diminishes a few minutes following fertilization. This decrease is correlated with a decrease in the total amount of 4E-BP in combination with an increase in the phosphorylation of the protein. We propose that 4E-BP acts as a repressor of protein synthesis in unfertilized sea urchin eggs and that 4E-BP/eIF4E dissociation plays an important role in the rise in protein synthesis that occurs shortly following fertilization.


Assuntos
Proteínas de Transporte/metabolismo , Fertilização/fisiologia , Fatores de Iniciação de Peptídeos/metabolismo , Ouriços-do-Mar/metabolismo , Animais , Fator de Iniciação 4E em Eucariotos , Feminino , Masculino , Óvulo/metabolismo , Iniciação Traducional da Cadeia Peptídica , Fosforilação , Testes de Precipitina , Biossíntese de Proteínas , RNA Mensageiro/metabolismo , Ribossomos/metabolismo
16.
Nucleic Acids Res ; 29(7): 1453-7, 2001 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-11266545

RESUMO

Eukaryotic elongation factor 1 (eEF-1) contains the guanine nucleotide exchange factor eEF-1B that loads the G protein eEF-1A with GTP after each cycle of elongation during protein synthesis. Two features of eEF-1B have not yet been elucidated: (i) the presence of the unique valyl-tRNA synthetase; (ii) the significance of target sites for the cell cycle protein kinase CDK1/cyclin B. The roles of these two features were addressed by elongation measurements in vitro using cell-free extracts. A poly(GUA) template RNA was generated to support both poly(valine) and poly(serine) synthesis and poly(phenylalanine) synthesis was driven by a poly(uridylic acid) template. Elongation rates were in the order phenylalanine > valine > serine. Addition of CDK1/cyclin B decreased the elongation rate for valine whereas the rate for serine and phenylalanine elongation was increased. This effect was correlated with phosphorylation of the eEF-1delta and eEF-1gamma subunits of eEF-1B. Our results demonstrate specific regulation of elongation by CDK1/cyclin B phosphorylation.


Assuntos
Proteína Quinase CDC2/metabolismo , Ciclina B/metabolismo , Biossíntese de Proteínas , Animais , Sistema Livre de Células , Fator 1 de Elongação de Peptídeos/metabolismo , Fenilalanina/metabolismo , Fosforilação , Proteínas/genética , RNA/genética , RNA/metabolismo , Coelhos , Reticulócitos/química , Reticulócitos/metabolismo , Serina/metabolismo , Moldes Genéticos , Fatores de Tempo , Valina/metabolismo
17.
Biochem Biophys Res Commun ; 266(2): 425-31, 1999 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-10600519

RESUMO

Using GST-EF-1 delta as an exogenous substrate, and EF-1 delta kinase activity was shown to increase transiently during early development of sea urchin embryos. The basal activity of EF-1 delta kinase in unfertilized eggs was 150 fmoles/min/mg protein. The activity began to increase 10 h after fertilization and reached its maximum level (8.4 x basal) at 24 h. The activity then declined to twice the basal value at 72 h post-fertilization. The EF-1 delta kinase activity was identified to a CK2-type enzyme on the basis of its substrate specificity for EF-1 delta, crude casein and beta casein, its inhibition by heparin, DRB, 2,3-bisphosphoglycerate, and its stimulation by spermine, spermidine, and polylysin. Furthermore, the activity was inhibited by the synthetic peptide RRREEETEEE specific for CK2. DRB (200 microM) and 2,3-bisphosphoglycerate (2.5 mM) blocked or delayed the transition from blastula to gastrula of the embryos, suggesting a role for the kinase in early development.


Assuntos
Proteínas Serina-Treonina Quinases/metabolismo , Ouriços-do-Mar/embriologia , Animais , Caseína Quinase II , Caseínas/metabolismo , Divisão Celular/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Oócitos/enzimologia , Fator 1 de Elongação de Peptídeos/metabolismo , Fosforilação , Proteínas Quinases/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Reprodução , Fatores de Tempo
18.
Gene ; 233(1-2): 83-7, 1999 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-10375624

RESUMO

The molecular evolution of two components of elongation factor-1 (EF-1), EF-1beta and EF-1delta was analysed using the distance matrix, the maximum parsimony and the maximum likelihood methods, after careful alignment of protein and cDNA sequences. The topology of the phylogenetic trees obtained supports monophyly of plant EF-1beta and EF-1beta' sequences, and monophyly of higher eukaryotic animal EF-1beta and EF-1delta sequences. EF-1beta and EF-1delta are homologous in their C-terminal domain. EF-1delta, which emerged before arthropods, originates from a beta-type ancestor gene and fusion with a leucine zipper N-terminal motif. Plant EF-1beta and EF-1beta' correspond to paralogous genes whose ancestor was most likely duplicated before the emergence of monocotyledons and dicotyledons.


Assuntos
Duplicação Gênica , Fatores de Alongamento de Peptídeos/genética , Sequência de Aminoácidos , Animais , Sequência Conservada , Humanos , Dados de Sequência Molecular , Fator 1 de Elongação de Peptídeos , Fatores de Alongamento de Peptídeos/química , Fatores de Alongamento de Peptídeos/metabolismo , Filogenia , Plantas/genética , Ligação Proteica , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Homologia de Sequência de Aminoácidos
19.
Biosci Rep ; 18(3): 119-27, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9798784

RESUMO

The eukaryotic guanine-nucleotide exchange factor commonly called elongation factor-1 betagammadelta (EF-1betagammadelta), comprises four different subunits including valyl-tRNA synthetase (EF-1betagammadelta/ValRS). The factor is multiply-phosphorylated by three different protein kinases, protein kinase C, casein kinase II and cyclin dependent kinase 1 (CDKI). EF-1betagammadelta/ValRS is organized as a macromolecular complex for which we propose a new structural model. Evidence that EF-1betagammadelta/ValRS is a sophisticated supramolecular complex containing many phosphorylation sites, makes it a potential regulator of any of the functions of its partner EF-1alpha, not only involved in protein synthesis elongation, but also in many other cellular functions.


Assuntos
Fatores de Alongamento de Peptídeos/fisiologia , Proteínas/fisiologia , Sítios de Ligação , Fatores de Troca do Nucleotídeo Guanina , Modelos Moleculares , Fator 1 de Elongação de Peptídeos , Fatores de Alongamento de Peptídeos/química , Fatores de Alongamento de Peptídeos/metabolismo , Fosforilação , Conformação Proteica , Proteínas/química , Proteínas/metabolismo
20.
Exp Cell Res ; 242(1): 228-34, 1998 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-9665820

RESUMO

Elongation factor-1 delta gene expression was analyzed during sea urchin development. EF-1 delta mRNA is present as a single 2.7-kb transcript in unfertilized eggs and in rapidly dividing cleavage stage embryos. It decreases rapidly 6 h after fertilization and then reappears at the gastrula stage as two transcripts of 2.7 and 2.0 kb. cDNA clones encoding the 2.7- and 2.0-kb transcripts were isolated from a sea urchin embryos library. The two cDNAs originate from alternative poly(A) site selection from a unique precursor. Both cDNAs are terminated by a poly(A) tail and were shown to encode for the same protein identified as EF-1 delta. Thus, EF-1 delta gene expression undergoes developmental regulation in early embryos leading to the presence of two poly(A) forms of the transcript. Since the 2.0-kb polyadenylated form of the EF-1 delta transcript appears at gastrula stage, our results suggest that a mechanism for alternative poly(A) site selection of the EF-1 delta transcript appears during embryonic development.


Assuntos
Gástrula , Regulação da Expressão Gênica no Desenvolvimento/genética , Fatores de Alongamento de Peptídeos/genética , RNA Mensageiro/genética , Ouriços-do-Mar/genética , Sequência de Aminoácidos , Animais , Clonagem Molecular , DNA Complementar/genética , Zíper de Leucina/genética , Dados de Sequência Molecular , Fator 1 de Elongação de Peptídeos , Biossíntese de Proteínas/genética , Ouriços-do-Mar/embriologia , Análise de Sequência de DNA , Transcrição Gênica/genética
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