Search results for "INITIATION"
showing 10 items of 174 documents
Yeast Translation Elongation Factor eIF5A Expression Is Regulated by Nutrient Availability through Different Signalling Pathways
2020
Translation elongation factor eIF5A binds to ribosomes to promote peptide bonds between problematic amino acids for the reaction like prolines. eIF5A is highly conserved and essential in eukaryotes, which usually contain two similar but differentially expressed paralogue genes. The human eIF5A-1 isoform is abundant and implicated in some cancer types
Reiterative transcription initiation from galP2 promoter of Escherichia coli
2000
The expression of gal operon in Escherichia coli is driven by two promoters, P1 and P2 separated by 5 bp. The transcription initiated from the P2 generates a large amount of abortive transcripts to produce a comparable amount of full-length transcript as P1 in vitro. In this study, we investigated the source of the abortive transcripts by employing a quantitative potassium permanganate footprinting method that determines the extent of open promoter complex formation. The extents of open promoter complex formation at the two gal promoters were about the same during the given reaction time while the amount of transcription initiation determined by in vitro transcription assay showed a conside…
Molecular dissection of human Argonaute proteins by DNA shuffling.
2013
A paramount task in RNA interference research is to decipher the complex biology of cellular effectors, exemplified in humans by four pleiotropic Argonaute proteins (Ago1-Ago4). Here, we exploited DNA family shuffling, a molecular evolution technology, to generate chimeric Ago protein libraries for dissection of intricate phenotypes independently of prior structural knowledge. Through shuffling of human Ago2 and Ago3, we discovered two N-terminal motifs that govern RNA cleavage in concert with the PIWI domain. Structural modeling predicts an impact on protein rigidity and/or RNA-PIWI alignment, suggesting new mechanistic explanations for Ago3's slicing deficiency. Characterization of hybrid…
Solution Structure of the R3H Domain from Human Sμbp-2
2003
The R3H domain is a conserved sequence motif, identified in over 100 proteins, that is thought to be involved in polynucleotide-binding, including DNA, RNA and single-stranded DNA. In this work the 3D structure of the R3H domain from human Smubp-2 was determined by NMR spectroscopy. It is the first 3D structure determination of an R3H domain. The fold presents a small motif, consisting of a three-stranded antiparallel beta-sheet and two alpha-helices, which is related to the structures of the YhhP protein and the C-terminal domain of the translational initiation factor IF3. The similarities are non-trivial, as the amino acid identities are below 10%. Three conserved basic residues cluster o…
Mir-661: A key Factor in Embryo-Maternal dialog With Potential Clinical Application to Predict Implantation Outcome?
2015
Implantation resulting in a full-term pregnancy is, by large, more than a passive process in which the developed conceptus is passively glued to the uterus through adhesive molecules. It is the result of a perfectly orchestrated dialog between a viable embryo and a receptive endometrium, through a mixture of paracrine and juxtacrine processes in which many key proteins and growth factors play fundamental roles (Pellicer et al., 2002.) Since their discovery, microRNAs have become prominent regulatory candidates, providing missing links for a few biological pathways in this process, although their exact role in human normal embryo formation and endometrial preparation for pregnancy remains un…
Oncogene-Associated Growth Behavior and Oxygenation of Multicellular Spheroids from Rat Embryo Fibroblasts
1994
It is now well documented that naturally occurring and experimentally induced tumors develop by a multistep process involving different stages such as unlimited growth, metastasis, and invasiveness. There is much evidence that malignant transformation involves activation of oncogenes and/or loss of suppressor genes (= anti-oncogenes). The former fundamental class of genes, including the ras and myc families, are associated with cell proliferation and differentiation and may mediate tumor initiation, promotion and progression (for reviews see: Spandidos, 1985; Spandidos and Anderson, 1987, Weinberg, 1989).
Time to initiation of adjuvant chemotherapy in patients with rapidly proliferating early breast cancer
2015
Aim To evaluate the optimal time interval from definitive surgery to commencing chemotherapy in early breast cancer (EBC). Patients and methods The relationship between time to initiation of adjuvant chemotherapy (TTC), calculated in weeks, and disease-free (DFS) or overall survival (OS), was assessed in 921 EBC patients with rapidly proliferating tumours (thymidine labelling index >3% or G3 or Ki67 >20%), randomised in a phase III clinical trial (NCT01031030) to receive chemotherapy with or without anthracyclines (epirubicin → cyclophosphamide, methotrexate and fluorouracil (CMF) versus CMF → epirubicin versus CMF). DFS, OS and 95% confidence intervals (95% confidence interval (CI)) …
Between Scylla and Charibdis: eIF2α kinases as targets for cancer chemotherapy
2011
[EN] The eIF2 alpha kinases integrate translation initiation rates with nutrient availability, thus allowing cells to adapt to nutrient scarcity. Recent evidence has uncovered new functions of these kinases in tumour cell biology, ranging from regulation of cell cycle progression, maintenance of genome stability, control of apoptosis, and cell survival under nutrient stress and hypoxia. Accordingly, active eIF2 alpha kinases modulate the antineoplasic activity of several antitumour drugs, either by exacerbating their cytotoxic effect or by promoting chemoresistance. Understanding of eIF2 alpha kinases molecular roles may provide mechanistic insights into how tumour cells sense and adapt to …
Influence of health literacy on maintenance of exclusive breastfeeding at 6 months postpartum: a multicentre study
2022
Data Availability Statement: Please note that the database is in an open repository. You can access the data through this link: http://hdl.handle.net/10234/196606 (accessed on 20 February 2022). Copyright © 2022 by the authors. Background: International organizations recommend initiating breastfeeding within the first hour of life and maintaining exclusive breastfeeding for the first 6 months. However, worldwide rates of exclusive breastfeeding for 6-month-old infants is far from meeting the goal proposed by the World Health Organization, which is to reach a minimum of 50% of infants. Education is one of the factors affecting the initiation and continuation of breastfeeding, and incidentall…
Psychosocial factors related to the competitive anxiety of sports in training stages
2017
El objetivo de este trabajo es indagar la relación existente entre la ansiedad competitiva de futbolistas y tenistas en etapas de formación y la práctica de deporte por parte de los progenitores. Participaron en este estudio 246 niños deportistas de tenis y fútbol con una media de edad de 10,43 años (DT= 2,42), que han sido evaluados con un cuestionario de datos sociodemográficos y el cuestionario de Ansiedad Competitiva SAS-2 (Ramis, Torregrosa, Viladrich, & Cruz, 2010). Utilizando pruebas t de diferencias de medias independientes y pruebas no paramétricas, los resultados demuestran que los tenistas experimentan más ansiedad somática, mientras que los deportistas de menor edad presentan ma…