Insertion of short hepatitis virus A amino acid sequences into poliovirus antigenic determinants results in viable progeny

AbstractIn an infectious poliovirus cDNA construct, the determinant encoding antigenic epitope N-Agl (in a loop located between two β-strands in polypeptide VP1) was altered by site-directed mutagenesis, to be partially similar with the determinants for presumptive epitopes in polypeptides VP1 or VP3 of hepatitis A virus (HAV). The modified constructs proved to be infectious. However, another construct, in which the same locus encoded a ‘nonsense’ and a relatively hydrophobic amino acid sequence, exhibited no infectivity. These data showed the feasibility of the insertion of foreign sequences in a specific antigenically active locus of the poliovirus icosahedron, and suggest some limitations with respect to the sequences to be ‘transplanted’

Antiapoptotic activity of the cardiovirus leader protein, a viral "security" protein

Apoptosis is a common antiviral defensive mechanism that potentially limits viral reproduction and spread. Many viruses possess apoptosis-suppressing tools. Here, we show that the productive infection of HeLa cells with encephalomyocarditis virus (a cardiovirus) was not accompanied by full-fledged apoptosis (although the activation of caspases was detected late in infection) but rather elicited a strong antiapoptotic state, as evidenced by the resistance of infected cells to viral and nonviral apoptosis inducers. The development of the antiapoptotic state appeared to depend on a function(s) of the viral leader (L) protein, since its mutational inactivation resulted in the efflux of cytochrome c from mitochondria, the early activation of caspases, and the appearance of morphological and biochemical signs of apoptosis in a significant proportion of infected cells. Infection with both wild-type and L-deficient viruses induced the fragmentation of mitochondria, which in the former case was not accompanied with cytochrome c efflux. Although the exact nature of the antiapoptotic function(s) of cardioviruses remains obscure, our results suggested that it includes previously undescribed mechanisms operating upstream and possibly downstream of the mitochondrial level, and that L is involved in the control of these mechanisms. We propose that cardiovirus L belongs to a class of viral proteins, dubbed here security proteins, whose roles consist solely, or largely, in counteracting host antidefenses. Unrelated L proteins of other picornaviruses as well as their highly variable 2A proteins also may be security proteins. These proteins appear to be independent acquisitions in the evolution of picornaviruses, implying multiple cases of functional (though not structural) convergence. Copyright © 2009, American Society for Microbiology. All Rights Reserved

ЭФФЕКТИВНОЕ УПРАВЛЕНИЕ ПЕРСОНАЛОМ КАК УСЛОВИЕ СОКРАЩЕНИЯ МИГРАЦИИ ВЫСОКОКВАЛИФИЦИРОВАННЫХ КАДРОВ ЗА РУБЕЖ

The article considers the actual for Russia problem of the growing number of immigrants with higher education. The analysis of the statistical measurement of migration of highly qualified personnel in our country and comparison with data from other sources (Eurostat). Special attention is paid to the effective practices of personnel management of high-tech enterprises (for example, JSC "RKS") as one of the ways to solve the problem of "brain drain". The strengths and weaknesses of such areas of personnel policy as the selection of personnel and its adaptation are considered. The problems associated with the training and development of personnel of high-tech enterprises, with the formation and maintenance of corporate culture. According to the results of the analysis conclusions.В статье рассматривается актуальная для РФ проблема роста числа эмигрантов с высшим образованием. Проведен анализ статистического измерения миграции высококвалифицированных кадров в нашей стране и сравнение с данными других источников (Евростата). Особое место уделено рассмотрению эффективных практик управления персоналом наукоемких предприятий (на примере АО «РКС») как одного из путей решения проблемы «утечки мозгов». Рассмотрены сильные и слабые стороны таких направлений кадровой политики, как отбор персонала и его адаптация. Выявлены проблемы, связанные с обучением и развитием персонала наукоемких предприятий, с формированием и поддержанием корпоративной культуры. По результатам проведенного анализа сделаны выводы

FREE AMINO ACID COMPOSITION IN SCOTS PINE TISSUES UNDER STRESS IMPACT IN RHIZOSPHERE

The free amino acid content in the needles and the inner bark of stems and roots of 8-13-ages self-sawn trees of Pinus sylvestris L. in Central Siberia in experimental and natural conditions was compared. The experiments imitated an influence of long-seasonal or permafrost, soil drought and root hypoxia, concomitant flooding. The aim of the investigation was to expose the adaptive changes of these metabolites composition under stress impact. All of types of stress influences changed the total free amino acid content in the tissues of different morphological tree parts: the cooling of root system caused a deposit of free amino acids in overground tree part, the water deficit stimulated an accumulation of free amino acids in root inner bark, the flooding decreased the amino acid content in all tissues. The ratio in a group of amino acids with glutamic acid as metabolic precursor (-aminobutyric (GABA), proline, arginine, citrulline and ornithine) changed under different stress impact. The cold stress in rhizosphere caused GABA accumulation in the needles and stem but not in the roots in the period of soil thawing. The moderate moisture deficit had not an influence on GABA content, the flooding caused GABA accumulation only in new needles. The maximal exceeding above control were marked for the sum of arginine and its metabolic precursors citrulline and ornithine. The group of these compounds may be considered as stress metabolites for scots pine, but specificity of depositing of these amino acids at water stress requires additional proofs. Since the proline accumulation was showed in separate times in the different tissues under all of investigated stressors impact, the specificity of proline as indicator of water stress in scots pine tissues is debatable. The disturbance of donor-acceptor connections in experiment with cooling resulted to the amino acid accumulation in stem inner bark, in experiment with drought – in root inner bark

Interactions between viral and prokaryotic pathogens in a mixed infection with cardiovirus and mycoplasma.

Contains fulltext : 80134.pdf (publisher's version ) (Open Access)In the natural environment, animal and plant viruses often share ecological niches with microorganisms, but the interactions between these pathogens, although potentially having important implications, are poorly investigated. The present report demonstrates, in a model system, profound mutual effects of mycoplasma and cardioviruses in animal cell cultures. In contrast to mycoplasma-free cells, cultures contaminated with Mycoplasma hyorhinis responded to infection with encephalomyocarditis virus (EMCV), a picornavirus, but not with poliovirus (also a picornavirus), with a strong activation of a DNase(s), as evidenced by the TUNEL (terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling) immunofluorescence assay and electrophoretic analysis of host DNA. This degradation was reminiscent of that observed upon apoptosis but was caspase independent, judging by the failure of the specific pan-caspase inhibitor Q-VD-OPh to prevent it. The electrophoretic mobility of the enzyme responsible for DNA degradation and dependence of its activity on ionic conditions strongly suggested that it was represented by a DNase(s) of mycoplasma origin. In cells not infected with EMCV, the relevant DNase was dormant. The possibility is discussed that activation of the mycoplasma DNase might be linked to a relatively early increase in permeability of plasma membrane of the infected cells caused by EMCV. This type of unanticipated virus-mycoplasma "cooperation" may exemplify the complexity of pathogen-host interactions under conditions when viruses and microorganisms are infecting the same host. In the course of the present study, it was also demonstrated that pan-caspase inhibitor zVAD(OMe).fmk strongly suppressed cardiovirus polyprotein processing, illustrating an additional pitfall in investigations of viral effects on the apoptotic system of host cells

Photovaractor performance for optically controlled microwave circuits

The photovaractor for optically controlled microwave circuits was designed and studied. The photovaractor module was fabricated as a planar p-i-n photodiode chip placed in a fibre optic matching receptacles. Study of C-V characteristics in the light illumination mode has shown that capacitance characteristics are strongly dependent on the light illumination power. These variations of the photovaractor diode capacitance are large enough to be used in optically controlled circuits such as oscillators, mixers and switchers