Search results for "nucleus"
showing 10 items of 1803 documents
Cracking the nut: Geographical adjacency of sister taxa supports vicariance in a polytomic salamander clade in the absence of node support
2008
The urodelan genus Lyciasalamandra, which inhabits a relatively small area along the southern Turkish coast and some Aegean islands, provides an outstanding example of a diverse but phylogenetically unresolved taxon. Molecular trees contain a single basal polytomy that could be either soft or hard. We here use the information of nuclear (allozymes) and mitochondrial (fractions of the 16S rRNA and ATPase genes) datasets in combination with area relationships of lineages to resolve the phylogenetic relationships among Lyciasalamandra species in the absence of sufficient node support. We can show that neither random processes nor introgressive hybridization can be invoked to explain that the m…
Use of a running coupling in the NLO calculation of forward hadron production
2018
We address and solve a puzzle raised by a recent calculation [1] of the cross-section for particle production in proton-nucleus collisions to next-to-leading order: the numerical results show an un- reasonably large dependence upon the choice of a prescription for the QCD running coupling, which spoils the predictive power of the calculation. Specifically, the results obtained with a prescription formulated in the transverse coordinate space differ by one to two orders of magnitude from those obtained with a prescription in momentum space. We show that this discrepancy is an artefact of the interplay between the asymptotic freedom of QCD and the Fourier transform from coordinate space to mo…
Nuclear Translocation of Nuclear Transcription Factor-κB by α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid Receptors Leads to Transcription of …
2003
We describe a new molecular mechanism of cell death by excitotoxicity mediated through nuclear transcription factor κB (NFκB) in rat embryonic cultures of dopaminergic neurons. Treatment of mesencephalic cultures with α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) resulted in a number of changes that occurred selectively in dopaminergic neurons, including persistent elevation in intracellular Ca2+ monitored with Fura-2, and a significant increase in intramitochondrial oxidation of dihydrorhodamine 123, probably associated with transient increase of mitochondrial permeability, cytochrome c release, nuclear translocation of NFκB, and transcriptional activation of the oncogenep53.…
Toxicity of a dental adhesive compared with ionizing radiation and zoledronic acid
2015
Background: To determine the toxicity of aqueous dilutions of a universal self-priming dental adhesive (DA) and comparing these with those elicited by exposure to ionizing radiation (IR), Zoledronic acid (Z) treatment and the synergic effects of the combined treatment with IR+Z. Material and Methods: The genotoxic effect of DA was determined by the increase in the frequency of micronuclei in cytokinesis-blocked in cultured human lymphocytes before and after exposure to 2Gy of X-rays. The cytotoxic effect was studied by using the MTT cell viability test in normal prostate cell lines (PNT2) after exposure to different X-ray doses (0Gy-20Gy). The cell lines divided into different groups and tr…
A new technique for real-time analysis of caspase-3 dependent neuronal cell death
2007
Several markers are available to identify cells undergoing programmed cell death, but so far they are only applicable on fixed material. Therefore, no information on the kinetics of apoptosis can be obtained, although apoptosis is a dynamic cell process. Here, we describe a new technique that allows the real-time observation of the onset of apoptosis in primary neurons. Neurons are transfected with a plasmid that codes for a fluorescent protein localized in the soma. Upon activation of caspase-3, which represents the point-of-no-return in the apoptosis process, the fusion protein is cleaved and as a consequence translocates into the nucleus. The onset of apoptosis is thus visualized by tran…
Highlighting Curcumin-Induced Crosstalk between Autophagy and Apoptosis as Supported by Its Specific Subcellular Localization
2020
Curcumin, a major active component of turmeric (Curcuma longa, L.), is known to have various effects on both healthy and cancerous tissues. In vitro studies suggest that curcumin inhibits cancer cell growth by activating apoptosis, but the mechanism underlying the anticancer effect of curcumin is still unclear. Since there is a recent consensus about endoplasmic reticulum (ER) stress being involved in the cytotoxicity of natural compounds, we have investigated using Image flow cytometry the mechanistic aspects of curcumin&rsquo
The human first cell cycle: impact on implantation.
2013
The morphology of fertilization events has been related to successful implantation by subjective criteria (pronuclei score, pronuclei symmetry and position). This work first described these events by time-lapse technology and then compared the timings of fertilization events (second polar body extrusion, first and second pronuclei appearance, abuttal and fading) in implanted versus nonimplanted embryos in a 2-year cohort retrospective study. A total of 1448 transferred embryos from 842 patients undergoing intracytoplasmic sperm injection with oocyte donation were monitored, 212 embryos from treatments where the number of gestational sacs matched the number of transferred embryos and 687 emb…
Heat shock protein 27 is involved in SUMO-2/3 modification of heat shock factor 1 and thereby modulates the transcription factor activity
2009
Heat shock protein 27 (HSP27) accumulates in stressed cells and helps them to survive adverse conditions. We have already shown that HSP27 has a function in the ubiquitination process that is modulated by its oligomerization/phosphorylation status. Here, we show that HSP27 is also involved in protein sumoylation, a ubiquitination-related process. HSP27 increases the number of cell proteins modified by small ubiquitin-like modifier (SUMO)-2/3 but this effect shows some selectivity as it neither affects all proteins nor concerns SUMO-1. Moreover, no such alteration in SUMO-2/3 conjugation is achievable by another HSP, such as HSP70. Heat shock factor 1 (HSF1), a transcription factor responsib…
Reading the Evolution of Compartmentalization in the Ribosome Assembly Toolbox: The YRG Protein Family.
2016
Reconstructing the transition from a single compartment bacterium to a highly compartmentalized eukaryotic cell is one of the most studied problems of evolutionary cell biology. However, timing and details of the establishment of compartmentalization are unclear and difficult to assess. Here, we propose the use of molecular markers specific to cellular compartments to set up a framework to advance the understanding of this complex intracellular process. Specifically, we use a protein family related to ribosome biogenesis, YRG (YlqF related GTPases), whose evolution is linked to the establishment of cellular compartments, leveraging the current genomic data. We analyzed orthologous proteins …
SANS (USH1G) regulates pre-mRNA splicing by mediating the intra-nuclear transfer of tri-snRNP complexes
2021
Abstract Splicing is catalyzed by the spliceosome, a compositionally dynamic complex assembled stepwise on pre-mRNA. We reveal links between splicing machinery components and the intrinsically disordered ciliopathy protein SANS. Pathogenic mutations in SANS/USH1G lead to Usher syndrome—the most common cause of deaf-blindness. Previously, SANS was shown to function only in the cytosol and primary cilia. Here, we have uncovered molecular links between SANS and pre-mRNA splicing catalyzed by the spliceosome in the nucleus. We show that SANS is found in Cajal bodies and nuclear speckles, where it interacts with components of spliceosomal sub-complexes such as SF3B1 and the large splicing cofact…