Loss of Trabid,a New Negative Regulator of the Drosophila Immune-Deficiency Pathway at the Level of TAK1, Reduces Life Span

A relatively unexplored nexus in Drosophila Immune deficiency (IMD) pathway is TGF-beta Activating Kinase 1 (TAK1), which triggers both immunity and apoptosis. In a cell culture screen, we identified that Lysine at position 142 was a K63-linked Ubiquitin acceptor site for TAK1, required for signalling. Moreover, Lysine at position 156 functioned as a K48-linked Ubiquitin acceptor site, also necessary for TAK1 activity. The deubiquitinase Trabid interacted with TAK1, reducing immune signalling output and K63-linked ubiquitination. The three tandem Npl4 Zinc Fingers and the catalytic Cysteine at position 518 were required for Trabid activity. Flies deficient for Trabid had a reduced life span due to chronic activation of IMD both systemically as well as in their gut where homeostasis was disrupted. The TAK1-associated Binding Protein 2 (TAB2) was linked with the TAK1-Trabid interaction through its Zinc finger domain that pacified the TAK1 signal. These results indicate an elaborate and multi-tiered mechanism for regulating TAK1 activity and modulating its immune signal.     

Effect of Mechanical Vibrations on the lonMutant of Escherichia coliK-12

It was found that, depending on their frequency, mechanical vibrations (MVs) can either stimulate (4 Hz) or inhibit (50 Hz) the growth and the division of the lonmutant of Escherichia coliK-12. Similar effects were observed when the MV-treated nutrient medium was inoculated with untreated mutant cells. MVs enhanced the motility of mutant cells and the fragmentation of filament cells always present in the populations of lonmutants.     

Study on the mechanism of Bioelectric Recognition Assay: evidence for immobilized cell membrane interactions with viral fragments

The Bioelectric Recognition Assay (BERA) is a whole-cell based biosensing system that detects the electric response of cultured cells, suspended in a gel matrix, to various ligands, which bind to the cell and/or affect its physiology. Previous studies have demonstrated the potential application of this method for rapid, inexpensive detection of viruses in a crude sample. However, the understanding, so far, of the fundamental processes that take place during cell-virus interactions within the probe has been rather limited. In the present study, we combined electrophysiological and fluorescence microscopical assays, so that we can prove that animal and plant cells immobilized in BERA sensors respond to different viruses primarily by changing their membrane potential. The response of immobilized cells against different viruses did not depend on the virus ability to penetrate the cell, but was modified after binding each virus to a virus-specific antibody or removal of its coat protein after treatment with a protease. Consequently, we were able to assay the presence of a virus in its complete form or fragments thereof. Combination of immunological recognition with the electrophysiological response of immobilized cells allows for a considerable increase of the specificity of the BERA biosensory assay. In addition, rather than simply detect the presence of a protein or genomic sequence, the method can help gain information on the bioactivity of a virus.     

Probing the geometric and electronic structures of the low-temperature azide adduct and the product-inhibited form of oxidized manganese superoxide dismutase

The geometric and electronic structures of the six-coordinate azide adduct of oxidized manganese superoxide dismutase (Mn3+ SOD) that is formed at low temperatures, LT N3-Mn3+ SOD, has been examined in detail through a combined spectroscopic/computational approach. Electronic absorption, circular dichroism (CD), magnetic CD (MCD) and variable-temperature, variable-field (VTVH) MCD spectroscopies were used to determine electronic transition energies and to obtain an estimate of zero-field splitting parameters for LT N3-Mn3+ SOD. These experimental data were utilized in conjunction with semiempirical intermediate neglect of differential overlap/spectroscopic parametrization-configuration interaction (INDO/S-CI) and time-dependent density functional theory (TD-DFT) computations to evaluate hypothetical active-site models of LT N3-Mn3+ SOD generated by constrained DFT geometry optimizations. Collectively, our spectroscopic/computational results indicate that N3- binding to Mn3+ SOD at low temperatures promotes neither protonation of the axial solvent ligand nor reorientation of the redox-active molecular orbital, both of which had been previously suggested. Using the same experimentally validated computational approach, models of the product-inhibited form of MnSOD were also developed and evaluated by their relative energies and TD-DFT-computed absorption spectra. On the basis of our computational results as well as previously published kinetic data, we propose that the product-inhibited form of MnSOD is best described as a side-on peroxo-Mn3+ adduct possessing an axial H2O ligand. Notably, attempts to generate a stable hydroperoxo-Mn3+ SOD species by protonation of the proximal O atom of the hydroperoxo ligand resulted in dissociation of HOO- and eventual H+ transfer from Tyr34 to HOO-, generating deprotonated Tyr34 and H2O2. The implications of these results with respect to the mechanism of O2*- dismutation by MnSOD are discussed.     

Influence of hypothalamic proline-rich peptide on the level of [14C]glucose utilization during crush syndrome

The number of publications on the investigation of crush syndrome (CS) pathogenesis at traumatic toxicosis is rather limited. The influence of some pharmacological preparations on the development of CS pathogenesis is not very well clarified. Proline-rich peptide (PRP) is a fragment of a glycopeptide comprising the carboxyterminus of the neurohypophyseal vasopressin-neurophysin precursor isolated from the bovine neurohypophysis neurosecretory granules. The polypeptide possesses stimulating activity on differentiation and proliferation of T-lymphocytes and Interleukin-2 (Il-2) biosynthesis. The experimental model of CS of white rats was induced by 2-h of compression followed by 2, 24, and 48-h of decompression of femoral muscle tissue. The influence of PRP on [¹⁴C]glucose utilization was investigated in brain, heart, and kidney tissues. The level of [¹⁴C]glucose utilization decreased in brain during compression followed by 2-h and 24-h of decompression, while it increased under the influence of PRP at all decompression periods. The influence of PRP on the myocardium and kidneys differs, depending on its nature and on the periods of decompression.     

Genetic Variability and the Potential Range of Darevskia rostombekowi in Transcaucasia

Biology Bulletin - The results of the analysis of the genetic variability of parthenogenetic Darevskia rostombekowi (Darevsky, 1957) species using four microsatellite-containing loci are presented....     

Ligand Absorption on DNA Duplexes under the Influence of a Fluctuating Medium Changes the Output Signal of a DNA Biosensor

Biophysics - Ligand binding to DNA duplexes in a DNA biosensor was studied in conditions where the number of ligand molecules in the solution fluctuates under the influence of a fluctuating medium...     

Cell bathing medium as a target for non thermal effect of millimeter waves

Non thermal (NT) effect of direct radiation 4?Hz-modulated 90-160?GHz of Millimeter Waves (MMW) and preliminary MMW-treated physiological solution (PS) influence were studied on snail isolated neuron, rat's brain tissue hydration and skin penetration. It was shown that the 4?Hz-modulated low intensity 90-160?GHz MMW direct radiation and MMW-treated PS leads to on single neuron shrinkage, skin and brain tissue dehydration. On the basis of obtained data it was suggested that the cell bathing aqua medium serve as a target through which the NT effect of MMW on cell hydration is realized. The MMW-induced brain tissue dehydration can considering as consequence of MMW-induced skin water structural changes leading to unknown messenger formation able to modulate the brain cell hydration. The extrasensitivity of cell hydration to low intensity of MMW radiation allow to recommend cell hydration as a cellular marker for estimation of the NT biological effect of MMW on cells and organisms.