scholarly journals Tetracycline Induces Stabilization of mRNA in Bacillus subtilis

2002 ◽  
Vol 184 (4) ◽  
pp. 889-894 ◽  
Author(s):  
Yi Wei ◽  
David H. Bechhofer
Keyword(s):  
Bacillus Subtilis ◽  
Mrna Stability ◽  
The Other ◽  
Leader Region ◽  
Subinhibitory Concentration ◽  
Coding Sequence ◽  
Mrna Stabilization ◽  
Threefold Increase ◽  
The Stability

ABSTRACT The tet(L) gene of Bacillus subtilis confers low-level tetracycline (Tc) resistance. Previous work examining the >20-fold-inducible expression of tet(L) by Tc demonstrated a 12-fold translational induction. Here we show that the other component of tet(L) induction is at the level of mRNA stabilization. Addition of a subinhibitory concentration of Tc results in a two- to threefold increase in tet(L) mRNA stability. Using a plasmid-borne derivative of tet(L) with a large in-frame deletion of the coding sequence, the mechanism of Tc-induced stability was explored by measuring the decay of tet(L) mRNAs carrying specific mutations in the leader region. The results of these experiments, as well as experiments with a B. subtilis strain that is resistant to Tc due to a mutation in the ribosomal S10 protein, suggest different mechanisms for the effects of Tc on translation and on mRNA stability. The key role of the 5" end in determining mRNA stability was confirmed in these experiments. Surprisingly, the stability of several other B. subtilis mRNAs was also induced by Tc, which indicates that addition of Tc may result in a general stabilization of mRNA.

MODELING THE ROLE OF DISSOLVED OXYGEN-DEPENDENT BACTERIA ON BIODEGRADATION OF ORGANIC POLLUTANTS

2014 ◽  
Vol 07 (01) ◽  
pp. 1450008 ◽  
Author(s):  
J. B. SHUKLA ◽  
ASHISH GOYAL ◽  
P. K. TIWARI ◽  
A. K. MISRA
Keyword(s):  
Dissolved Oxygen ◽  
Water Body ◽  
Logistic Model ◽  
Simulation Analysis ◽  
Organic Pollutant ◽  
The Other ◽  
Nonlinear Mathematical Model ◽  
The Stability ◽  
The One

In this paper, a nonlinear mathematical model is proposed and analyzed to study the role of dissolved oxygen (DO)-dependent bacteria on biodegradation of one or two organic pollutant(s) in a water body. In the case of two organic pollutant(s), it is assumed that the one is fast degrading and the other is slow degrading and both are discharged into the water body from outside with constant rates. The density of bacteria is assumed to follow logistic model and its growth increases due to biodegradation of one or two organic pollutant(s) as well as with the increase in the concentration of DO. The model is analyzed using the stability theory of differential equations and by simulation. The model analysis shows that the concentration(s) of one or both organic pollutant(s) decrease(s) as the density of bacteria increases. It is noted that for very large density of bacteria, the organic pollutant(s) may be removed almost completely from the water body. It is found that simulation analysis confirms the analytical results. The results obtained in this paper are in line with the experimental observations published in literature.

Possible Perforin-Munc13-4 Gene-Gene Interaction in Familial Hemophagocytic Lymphohistiocytosis

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4643-4643
Author(s):  
Gunay Balta ◽  
Hamza Okur ◽  
Nurten Akarsu ◽  
Sule Unal ◽  
Cigdem Altay ◽  
...  
Keyword(s):  
Risk Factor ◽  
Genetic Risk ◽  
Genetic Risk Factor ◽  
The Other ◽  
Familial Hemophagocytic Lymphohistiocytosis ◽  
The Family ◽  
Syntaxin 11 ◽  
The Stability ◽  
Asymptomatic Sibling

Abstract Familial hemophagocytic lymphohistiocytosis (FHL) is an autosomal recessive immune dysregulation disorder associated with Perforin, Munc13-4 and Syntaxin 11 genes. The mutations in the Perforin gene are the most common cause of the disease. Among these mutations, the role of the Alanin91Valin (A91V) alteration in the pathogenesis of the disease has long been controversial. Even though this alteration can be considered as a polymorphism based on its high frequency in normal population (>3.7%) and homozygous existence in some healthy individuals, it is also considered as a genetic risk factor depending on its much higher frequency observed in FHL patients (22.7%) and compound heterozygous existence with other disease causing mutations in the Perforin gene in some FHL patients. Contrary to the previous publications concerning with the co-existence of heterozygous A91V with homozygous mutations in other described FHL genes, there has been no reports on homozygous co-existence of A91V up until this communication where we present the interesting results of a study which shed light not only on the role of A91V in development of FHL, but also on the etiopathogenesis of genetic diseases in general. The subject of the study was a 12 year old female patient who was a product of a first degree consanguineous marriage. Initial diagnosis was lymphomatoid granulomatosis due to the presence of symptoms associated solely with central nervous system. The correct diagnosis could be made 1 year later upon development of systemic findings of FHL. There was no history of similar disorder in the family. Linkage analysis in the family revealed homozygosity for both Perforin and Munc13-4 genes in the patient and for only Munc13-4 gene in one of the asymptomatic sibling who was heterozygous for Perforin gene. Syntaxin 11 gene was excluded in this analysis. Detected merely in the patient was a homozygous A91V substitution (272C>T) in the sequencing of the Perforin gene. Sequencing of the complete coding (32 exons) and the flanking sequences, on the other hand, led to the identification of a homozygous three nucleotide in-frame deletion (2135-2137delTCG) in exon 23 of Munc13-4 gene. This novel mutation resulted in the replacement of nonpolar two aminoacids (Ile-Gly) at positions 712-713 with a polar single aminoacid (Ser). It is plausible that the substitution of highly conserved two aminoacids, especially one (Ile) playing important role in the stability of proteins, with a hydrophilic one would alter the three dimensional structure and the stability of the protein, and would lead to FHL. Ironically, however, an asymptomatic sibling who is currently 22 year old was also homozygous for the mutation. This finding led to the assumption that the Munc13-4 mutation alone may not be sufficient for the development of the disease, but may be a genetic risk factor requiring co-existence of additional homozygous genetic risk factor situated in another FHL gene. If this is the case, it is reasonable to state that homozigosity for A91V in Perforin as well as homozygosity for the 2135-2137del mutation in Munc13-4 is a strong genetic susceptibility factor contributing significantly to the pathogenesis of the disease when they are co-existed. However, this notion could be valid as long as the sibling with homozygous Munc13-4 mutation stays asymptomatic. On the other hand, late onset and atypical presentation in the propositus may indicate that the homozygous co-existence of both alterations is not associated with serious clinical course of the disease as far as the presenting age of the disease is concerned.

scholarly journals High NaCl increases TonEBP/OREBP mRNA and protein by stabilizing its mRNA

2005 ◽  
Vol 289 (4) ◽  
pp. F803-F807 ◽  
Author(s):  
Qi Cai ◽  
Joan D. Ferraris ◽  
Maurice B. Burg
Keyword(s):  
Mrna Stability ◽  
Collecting Duct ◽  
Rna Stability ◽  
Mrna Stabilization ◽  
Reporter Activity ◽  
Osmotic Response ◽  
Element Binding Protein ◽  
Collecting Duct Cells ◽  
Medullary Collecting Duct ◽  
The Stability

Hypertonicity increases mRNA and protein abundance of the transcription factor tonicity-responsive enhancer/osmotic response element binding protein (TonEBP/OREBP), contributing to increased transcription of downstream osmoprotective genes. Previously, this was attributed to increased transcription of TonEBP/OREBP because no change was found in its mRNA stability. However, there is no direct evidence for increased transcription, and the 3′-untranslated region (UTR) of TonEBP/OREBP contains numerous adenylate/uridylate-rich elements, which can modulate RNA stability. Therefore, we have reinvestigated the effect of hypertonicity on TonEBP/OREBP mRNA stability. We find that, in mouse inner medullary collecting duct cells, raising osmolality from 300 to 500 mosmol/kgH2O by adding NaCl increases TonEBP/OREBP mRNA to a peak of 2.3-fold after 4 h, followed by a decline. TonEBP/OREBP protein increases to a sustained peak of 3.0-fold at 8 h. To determine the stability of TonEBP/OREBP mRNA, we measured the rate of its decrease after inhibiting transcription with actinomycin D, finding that it is stabilized for 6 h after addition of NaCl. This stabilization is sufficient to explain the increase in mRNA without any change in transcription. To investigate how hypertonicity stabilizes TonEBP/OREBP mRNA, we tested luciferase reporters containing parts of the TonEBP/OREBP mRNA UTR. Inclusion of both the 5′- and 3′-UTR increases reporter activity, consistent with mRNA stabilization. Surprisingly, however, it is the 5′-UTR that stabilizes; the 3′-UTR, by itself, decreases reporter activity. We concluded that 1) hypertonicity stabilizes TonEBP/OREBP mRNA, contributing to its increase, and 2) stabilization depends on the presence of the 5′-UTR.

Ti-Ni Phase Diagram with Applied Stress

1993 ◽  
Vol 311 ◽  
Author(s):  
A.Peter Jardine
Keyword(s):  
Thin Film ◽  
Phase Diagram ◽  
Single Phase ◽  
Phase Evolution ◽  
The Other ◽  
Β Phase ◽  
The Stability ◽  
Tini Phase ◽  
Rich Side

ABSTRACTThe role of stress on the phase evolution of thin-film TiNi has not been investigated and may play an important role in the phase evolution of thin film TiNi. In this paper, a preliminary set of phase diagrams for Ni-Ti at different pressures are presented relating the stability of the stoichiometric TiNi phase to the other well-documented intermetallics TiNi3 and NiTi2. It is found that for sufficient pressure of the order of a GPa, the region where NiTi (β) phase is single phase shifts towards the Ti-rich side of the diagram. The implications on the annealing of TiNi thin film is discussed.

scholarly journals The Role of Polarity on the Stability of Graphitic Compounds

1989 ◽  
Vol 162 ◽  
Author(s):  
Renata M. Wentzcovitch ◽  
Alessandra Continenza ◽  
A. J. Freeman
Keyword(s):  
The Other ◽  
Low Density ◽  
Hexagonal Diamond ◽  
The Family ◽  
The Stability

ABSTRACTThere is an old puzzle associated with the series of compounds formed by first row elements, C, BN, and BeO: similar to the other members of the family of octet semiconductors, these compounds exist in dense phases like diamond and zincblende, or hexagonal diamond (lonsdaleite) and wurtzite; however, whereas C and BN also exist in low density graphitic phases, BeO does not.

THE ROLE OF RESONANCES IN PLANETARY SYSTEMS

2006 ◽  
Vol 16 (06) ◽  
pp. 1633-1644
Author(s):  
RUDOLF DVORAK
Keyword(s):  
Planetary Systems ◽  
The Other ◽  
Special Configuration ◽  
Small Bodies ◽  
Mean Motion Resonances ◽  
Extrasolar Systems ◽  
Eccentric Orbits ◽  
The Stability ◽  
Observational Techniques

This paper reviews the important role of resonances in the structure of planetary systems. After a short introduction to the basics of orbital dynamics of motion in resonances we describe the dynamics of our planetary systems and also of extrasolar planetary systems, where up to now more than 100 are known. In our planetary system the planets move in quite regular orbits with small eccentricities although it was found that the motion of the inner planets is "slightly" chaotic on time scales of tenths of millions of years. The quasi regularity (close to so-called quasi-periodic motion on a torus) is not true for the small bodies: the main belt of asteroids between Mars and Jupiter with gaps for special values of semimajor axes on one hand and with families of many small bodies on the other, is sculpted due to the presence of first mean motion resonances with Jupiter and second secular resonances with long-periodic motions of the nodes and perihelia of Jupiter and Saturn. In extrasolar systems the planets — rather surprisingly — are found to move sometimes in very high eccentric orbits when they are at distances comparable to the size of our planets. Because of our still limited observational techniques using indirect methods we have only discovered massive planets comparable to the size of Jupiter. When these planets orbit alone around their host star our research aims at the possibility of additional terrestrial planets moving in such a system. Because of mostly large eccentricities here the resonances are, in contrary to our planets, essential for the stability of orbits, and may protect or destroy an orbit. On the other hand, in multiple planetary systems we concentrate on the stability of their orbits as they are observed: a very interesting new result is that most of these multiple planetary systems with high eccentric orbits move in resonances with a special configuration which protects them from close encounters although these orbits are crossing.

scholarly journals Transcriptome-wide stability analysis uncovers LARP4-mediated NFκB1 mRNA stabilization during T cell activation

2020 ◽  
Vol 48 (15) ◽  
pp. 8724-8739
Author(s):  
Yi Tian ◽  
Zhouhao Zeng ◽  
Xiang Li ◽  
Yiyin Wang ◽  
Runsen Chen ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Mrna Stability ◽  
Cell Activation ◽  
Rna Binding ◽  
Intron Retention ◽  
Interleukin 2 ◽  
Mrna Stabilization ◽  
A Genome ◽  
The Stability

Abstract T cell activation is a well-established model for studying cellular responses to exogenous stimulation. Motivated by our previous finding that intron retention (IR) could lead to transcript instability, in this study, we performed BruChase-Seq to experimentally monitor the expression dynamics of nascent transcripts in resting and activated CD4+ T cells. Computational modeling was then applied to quantify the stability of spliced and intron-retained transcripts on a genome-wide scale. Beyond substantiating that intron-retained transcripts were considerably less stable than spliced transcripts, we found a global stabilization of spliced mRNAs upon T cell activation, although the stability of intron-retained transcripts remained relatively constant. In addition, we identified that La-related protein 4 (LARP4), an RNA-binding protein (RBP) known to enhance mRNA stability, was involved in T cell activation-dependent mRNA stabilization. Knocking out Larp4 in mice destabilized Nfκb1 mRNAs and reduced secretion of interleukin-2 (IL2) and interferon-gamma (IFNγ), two factors critical for T cell proliferation and function. We propose that coordination between splicing regulation and mRNA stability may provide a novel paradigm to control spatiotemporal gene expression during T cell activation.

scholarly journals Moonlighting Role of a Poly-γ-Glutamate Synthetase Component from Bacillus subtilis: Insight into Novel Extrachromosomal DNA Maintenance

2011 ◽  
Vol 77 (8) ◽  
pp. 2796-2798 ◽  
Author(s):  
Daisuke Yamashiro ◽  
Yutaka Minouchi ◽  
Makoto Ashiuchi
Keyword(s):  
Bacillus Subtilis ◽  
Selective Pressure ◽  
Extrachromosomal Dna ◽  
Content Type ◽  
Glutamate Synthetase ◽  
Acting Mechanism ◽  
The Stability ◽  
Dna Maintenance ◽  
Insight Into

ABSTRACTTheBacillus subtilisstructural genepgsEwas investigated as a tool for extrachromosomal DNA maintenance (EDM). It ameliorated the stability of high-copy-number vectors, regardless of whether they were derived from rolling-cycle or theta-mode replicons, without any selective pressure. This unique EDM phenomenon may occur via atrans-acting mechanism.

Unprecedented Role of The N73-F124 Pair in The Staphylococcus equorum MnSOD Activity

2020 ◽  
Vol 16 ◽  
Author(s):  
Debbie Soefie Retnoningrum ◽  
Hiromi Yoshida ◽  
Muthia Dzaky Razani ◽  
Vincencius Felix Meidianto ◽  
Andrian Hartanto ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Active Site ◽  
Manganese Superoxide Dismutase ◽  
Enzyme Stability ◽  
The Other ◽  
Site Directed Mutagenesis ◽  
X Ray Crystallography ◽  
Staphylococcus Equorum ◽  
The Stability

Background:: Bacterial manganese superoxide dismutase (MnSOD) occurs as a dimer, which is responsible for its activity and stability. Thereby, increasing the dimeric strength would increase the enzyme stability while maintaining its activity. Objective:: An N73F substitution was introduced to strengthen interactions between the monomers at the dimer interface. This substitution would introduce a π-stacking interaction between F73 of one monomer to F124 from the other monomer. Method:: Site-directed mutagenesis was carried out to substitute N73 with phenylalanine. The activity of the mutant was qualitative- and quantitatively checked while the stability was evaluated with a fluorescence-based thermal-shift assay. Finally, the structure of the mutant was elucidated by means of X-ray crystallography. Results:: The N73F mutant activity was only ~40% of the wildtype. The N73F mutant showed one TM at 60+1oC while the wildtype has two (at 52-55oC and 63-67oC). The crystal structure of the mutant showed the interactions between F73 from one monomer to F124 from the other monomer. The N73F structure presents an enigma because of no change in the enzyme structure including the active site. Furthermore, N73 and F124 position and interaction are conserved in human MnSOD but with a different location in the amino acid sequence. N73 has a role in the enzyme activity that is likely related to its interaction with F124, which resides in the active site region but has not been considered to participate in the reaction. Conclusion:: The N73F substitution has revealed the unprecedented role of the N73-F124 pair in the enzyme activity.

Uniformity of Magnification from Different Electron Microscopes

1967 ◽  
Vol 25 ◽  
pp. 32-33
Author(s):  
Godfrey C. Hoskins ◽  
V. Williams ◽  
V. Allison
Keyword(s):  
Diffraction Grating ◽  
The Other ◽  
Carbon Replica ◽  
Electron Microscopes ◽  
The Stability

The method demonstrated is an adaptation of a proven procedure for accurately determining the magnification of light photomicrographs. Because of the stability of modern electrical lenses, the method is shown to be directly applicable for providing precise reproducibility of magnification in various models of electron microscopes.A readily recognizable area of a carbon replica of a crossed-line diffraction grating is used as a standard. The same area of the standard was photographed in Phillips EM 200, Hitachi HU-11B2, and RCA EMU 3F electron microscopes at taps representative of the range of magnification of each. Negatives from one microscope were selected as guides and printed at convenient magnifications; then negatives from each of the other microscopes were projected to register with these prints. By deferring measurement to the print rather than comparing negatives, correspondence of magnification of the specimen in the three microscopes could be brought to within 2%.

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