Search results for "fusion"
showing 10 items of 4513 documents
The C-terminal region of the Hot1 transcription factor binds GGGACAAA-related sequences in the promoter of its target genes
2015
Response to hyperosmotic stress in the yeast Saccharomyces cerevisiae involves the participation of the general stress response mediated by Msn2/4 transcription factors and the HOG pathway. One of the transcription factors activated through this pathway is Hot1, which contributes to the control of the expression of several genes involved in glycerol synthesis and flux, or in other functions related to adaptation to adverse conditions. This work provides new data about the interaction mechanism of this transcription factor with DNA. By means of one-hybrid and electrophoretic mobility assays, we demonstrate that the C-terminal region, which corresponds to amino acids 610-719, is the DNA-bindi…
Convergence of the target of rapamycin and the Snf1 protein kinase pathways in the regulation of the subcellular localization of Msn2, a transcriptio…
2002
The subcellular localization of Msn2, a transcriptional activator of STRE (stress response element)-regulated genes, is modulated by carbon source availability. In cells growing in glucose, Msn2 is located mainly in the cytosol, whereas in carbon source-starved cells, Msn2 is located largely inside the nucleus. However, in cells lacking Reg1 (the regulatory subunit of the Reg1/Glc7 protein phosphatase complex), the regulation of subcellular distribution is absent, Msn2 being constitutively present in the cytosol. The localization defect in these mutants is specific for carbon starvation stress, and it is because of the presence of an abnormally active Snf1 protein kinase that inhibits the n…
Genetic analysis of maintenance and expression of L and M double-stranded RNAs from yeast killer virus K28
1992
The killer phenotype expressed by Saccharomyces cerevisiae strain 28 differs from that of the more extensively studied K1 and K2 killers with respect to immunity, mode of toxin action and cell wall primary toxin receptor. We previously demonstrated that the M28 and L28 dsRNAs found in strain 28 are present in virus-like particles (VLPs) and that transfection with these VLPs is sufficient to confer the complete K28 phenotype on a dsRNA-free recipient cell. We also demonstrated that L28, like the L-A-H species in K1 killers, has [HOK] activity required for maintenance of M1-dsRNA, and predicted that M28 would share with M1 dependence on L-A for replication. We now confirm this prediction by g…
Lateral reorganization of plasma membrane is involved in the yeast resistance to severe dehydration
2010
International audience; In this study, we investigated the kinetic and the magnitude of dehydrations on yeast plasma membrane (PM) modifications because this parameter is crucial to cell survival. Functional (permeability) and structural (morphology, ultrastructure, and distribution of the protein Sur7-GFP contained in sterol-rich membrane microdomains) PM modifications were investigated by confocal and electron microscopy after progressive (non-lethal) and rapid (lethal) hyperosmotic perturbations. Rapid cell dehydration induced the formation of many PM invaginations followed by membrane internalization of low sterol content PM regions with time. Permeabilization of the plasma membrane occ…
Evaluation of the SOS/umu-test post-treatment assay for the detection of genotoxic activities of pure compounds and complex environmental mixtures.
2000
This study presents an evaluation of the SOS/umu-test after introducing an additional dilution and incubation in the post-treatment assay. This treatment reduces the influence of coloured test compounds that otherwise affect the colorimetric determination of the beta-galactosidase activity and the bacterial growth measurement during the testing of complex environmental samples. The post-treatment assay significantly increased the beta-galactosidase activity and consequently the enzyme induction ratios at higher doses of model genotoxins 4-nitroquinoline-N-oxide, N-methyl-N'-nitro-N-nitrosoguanidine, 2-aminoanthracene, benzo(a)pyrene with low or no effect on the sensitivity of the test itsel…
Serotypes, Antibiotic Resistance, and Class 1 Integrons in Salmonella Isolates from Pediatric Cases of Enteritis in Tehran, Iran
2011
The present study was conducted to investigate serotype distribution, antimicrobial resistance patterns, carriage of class 1 integron, and clonality of Salmonella strains isolated from patients aged 0-12 years in Tehran, Iran, during 2007-2008. A total of 139 Salmonella isolates were studied. Salmonella serotypes Enteritidis, Infantis, and Typhimurium included 84.9% of isolates, Enteritidis accounting for 41.7%. The most prevalent resistances were to doxycycline (64.7%), nalidixic acid (61.2%), tetracycline (51.8%), and streptomycin (42.8%). Fifty-three (38.1%) isolates contained class 1 integron. Eight different gene cassettes were identified, aadA1 being the most frequently encountered. P…
Novel dual-flow perfusion bioreactor for in vitro pre-screening of nanoparticles delivery: design, characterization and testing
2021
An advanced dual-flow perfusion bioreactor with a simple and compact design was developed and evaluated as a potential apparatus to reduce the gap between animal testing and drug administration to human subjects in clinical trials. All the experimental tests were carried out using an ad hoc Poly Lactic Acid (PLLA) scaffold synthesized via Thermally Induced Phase Separation (TIPS). The bioreactor shows a tunable radial flow throughout the microporous matrix of the scaffold. The radial perfusion was quantified both with permeability tests and with a mathematical model, applying a combination of Darcy's Theory, Bernoulli's Equation, and Poiseuille's Law. Finally, a diffusion test allowed to in…
PLLA biodegradable scaffolds for angiogenesis via Diffusion Induced Phase Separation (DIPS)
2008
A critical obstacle in tissue engineering is the inability to maintain large masses of living cells upon transfer from the in vitro culture conditions into the host in vivo. Capillaries, and the vascular system, are required to supply essential nutrients, including oxygen, remove waste products and provide a biochemical communication “highway”. For this reason it is mandatory to manufacture an implantable structure where the process of vessel formation – the angiogenesis – can take place. In this work PLLA scaffolds for vascular tissue engineering were produced by dip-coating via Diffusion Induced Phase Separation (DIPS) technique. The scaffolds, with a vessel-like shape, were obtained by p…
Bag Scattering Theory
1986
We reanalyze the procedure used thus far for the study of collision processes in the Chiral Bag Model from the point of view of scattering theory. In the present formalism thein andout states are free waves with no memory of the cavity. This feature gives rise to an observable effect consisting in a peculiar momentum dependence of the scattering amplitudes, which differs from that of previous calculations. The new procedure however does not change the magnitude of the pion-baryon coupling constants.
Protein and solvent dynamics of the water-soluble chlorophyll-binding protein (WSCP)
2015
This study presents quasielastic neutron scattering data of the water-soluble chlorophyll-binding protein (WSCP) and the corresponding buffer solution at room temperature. The contributions of protein and buffer solution to the overall scattering are carefully separated. Otherwise, the fast water dynamics dominating the buffer contribution is likely to mask the slow protein dynamics. In the case of WSCP, the protein scattering can be described by two contributions: i) internal protein dynamics represented by a diffusion in a sphere with an average radius of 2.7 u A and ii) global (Brownian) diffusion of the WSCP macromolecule with an upper limit for the translational diffusion coefficient o…