Search results for "replica"
showing 10 items of 576 documents
Localization microscopy of DNA in situ using Vybrant(®) DyeCycle™ Violet fluorescent probe: A new approach to study nuclear nanostructure at single m…
2016
Higher order chromatin structure is not only required to compact and spatially arrange long chromatids within a nucleus, but have also important functional roles, including control of gene expression and DNA processing. However, studies of chromatin nanostructures cannot be performed using conventional widefield and confocal microscopy because of the limited optical resolution. Various methods of superresolution microscopy have been described to overcome this difficulty, like structured illumination and single molecule localization microscopy. We report here that the standard DNA dye Vybrant(®) DyeCycle™ Violet can be used to provide single molecule localization microscopy (SMLM) images of …
Doxorubicin anti-tumor mechanisms include Hsp60 post-translational modifications leading to the Hsp60/p53 complex dissociation and instauration of re…
2017
Hsp60 is a pro-carcinogenic chaperonin in certain tumor types by interfering with apoptosis and with tumor cell death. In these tumors, it is not known whether or not doxorubicin anti-tumor effects include a blockage of the pro-carcinogenic action of this protein. We used the human lung mucoepidermoid cell line NCI-H292 and different doses of doxorubicin to measure cell viability, cell cycle progression, cell senescence indicators, Hsp60 levels and its post-translational modifications as well as the release of the chaperonin into the extracellular environment. Cell viability was reduced in relation to doxorubicin dose and this was paralleled by the appearance of cell senescence markers. Con…
Lack of a peroxiredoxin suppresses the lethality of cells devoid of electron donors by channelling electrons to oxidized ribonucleotide reductase
2017
The thioredoxin and glutaredoxin pathways are responsible of recycling several enzymes which undergo intramolecular disulfide bond formation as part of their catalytic cycles such as the peroxide scavengers peroxiredoxins or the enzyme ribonucleotide reductase (RNR). RNR, the rate-limiting enzyme of deoxyribonucleotide synthesis, is an essential enzyme relying on these electron flow cascades for recycling. RNR is tightly regulated in a cell cycle-dependent manner at different levels, but little is known about the participation of electron donors in such regulation. Here, we show that cytosolic thioredoxins Trx1 and Trx3 are the primary electron donors for RNR in fission yeast. Unexpectedly,…
Identification of loci of functional relevance to Barrett's esophagus and esophageal adenocarcinoma: Cross-referencing of expression quantitative tra…
2019
Esophageal adenocarcinoma (EA) and its precancerous condition Barrett's esophagus (BE) are multifactorial diseases with rising prevalence rates in Western populations. A recent meta-analysis of genome-wide association studies (GWAS) data identified 14 BE/EA risk loci located in non-coding genomic regions. Knowledge about the impact of non-coding variation on disease pathology is incomplete and needs further investigation. The aim of the present study was (i) to identify candidate genes of functional relevance to BE/EA at known risk loci and (ii) to find novel risk loci among the suggestively associated variants through the integration of expression quantitative trait loci (eQTL) and genetic…
Collective Infection of Cells by Viral Aggregates Promotes Early Viral Proliferation and Reveals a Cellular-Level Allee Effect
2018
In addition to the conventional release of free, individual virions, virus dispersal can involve multi-virion assemblies that collectively infect cells. However, the implications of collective infection for viral fitness remain largely unexplored. Using vesicular stomatitis virus, here, we compare the fitness of free versus saliva-aggregated viral particles. We find that aggregation has a positive effect on early progeny production, conferring a fitness advantage relative to equal numbers of free particles in most cell types. The advantage of aggregation resides, at least partially, in increasing the cellular multiplicity of infection. In mouse embryonic fibroblasts, the per capita, short-t…
ICTV Virus Taxonomy Profile: Dicistroviridae
2017
Dicistroviridae is a family of small non-enveloped viruses with monopartite, linear, positive-sense RNA genomes of approximately 8–10 kb. Viruses of all classified species infect arthropod hosts, with some having devastating economic consequences, such as acute bee paralysis virus in domesticated honeybees and taura syndrome virus in shrimp farming. Conversely, the host specificity and other desirable traits exhibited by several members of this group make them potential natural enemies for intentional use against arthropod pests, such as triatoma virus against triatomine bugs that vector Chagas disease. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on…
High genetic stability of potato yellow mosaic Panama virus infecting tomato in Panama
2018
The relevant regions in Panama involved in commercial tomato production, including the Chiriqui, Veraguas, Herrera, Los Santos and Panama Oeste provinces, were surveyed for the distribution and genetic diversity of potato yellow mosaic Panama virus (PYMPV) in the growing seasons of 2011 and 2012. A total of 28 tomato plots were surveyed and 314 individual tomato plants were sampled. DNA was extracted from each plant for a subsequent rolling circle amplification (RCA) analysis, to confirm the presence of begomovirus infections. The samples displaying a positive RCA reaction were subsequently analysed by PCR with a specific primer pair to identify PYMPV. This virus was detected in samples col…
Cyclins B1, T1, and H differ in their molecular mode of interaction with cytomegalovirus protein kinase pUL97
2019
Human cytomegalovirus (HCMV) is a common β-herpesvirus causing life-long latent infections. HCMV replication interferes with cell cycle regulation in host cells because the HCMV-encoded cyclin-dependent kinase (CDK) ortholog pUL97 extensively phosphorylates the checkpoint regulator retinoblastoma protein. pUL97 also interacts with cyclins B1, T1, and H, and recent findings have strongly suggested that these interactions influence pUL97 substrate recognition. Interestingly, here we detected profound mechanistic differences among these pUL97-cyclin interactions. Our study revealed the following. (i) pUL97 interacts with cyclins B1 and H in a manner dependent on pUL97 activity and HCMV-specifi…
DNA Injury and Repair Systems
2018
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The MRN complex is transcriptionally regulated by MYCN during neural cell proliferation to control replication stress
2015
The MRE11/RAD50/NBS1 (MRN) complex is a major sensor of DNA double strand breaks, whose role in controlling faithful DNA replication and preventing replication stress is also emerging. Inactivation of the MRN complex invariably leads to developmental and/or degenerative neuronal defects, the pathogenesis of which still remains poorly understood. In particular, NBS1 gene mutations are associated with microcephaly and strongly impaired cerebellar development, both in humans and in the mouse model. These phenotypes strikingly overlap those induced by inactivation of MYCN, an essential promoter of the expansion of neuronal stem and progenitor cells, suggesting that MYCN and the MRN complex migh…