International conference on bioinformatics of genome regulation
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Key words: 8-oxo-2’-deoxyguanosine, “stationary aging”, exogenous 8-oxo-dG, biomarker of aging 8-Oxo-dG is one of the popular biomarkers of aging and oxidative stress. Its content in DNA increases in aging of humans, animals and cell cultures. The process takes place also in cancer, inflammatory, infectious, neurodegenerative diseases and in some stress- ful conditions related to smoking, diet modifications, athletic exercises, etc. According to a commonly held view, 8-oxo-dG is just a “waste product” removed from the dam- aged DNA. However, in the last years some data appeared which proved a possible role of 8-oxo-dG in the regulation of biological processes. In particular, it is capable of exerting anti-inflammatory and antiallergic effect, increasing survival of organisms by irradiation, hypoxia, and starvation. The objective of our research was to identify the possible biological effects of 8-oxo-dG in cell culture, in which they can not be due to immune and neurohumoral mechanisms, and are solely the result of direct exposure to a substance on a cellular level. The experiments used culture of transformed Chinese hamster cells line B11-dii FAF28. To measure the content of 8-oxo-dG in DNA method of RP HPLC with EC detectionwas used. During the experiments we have shown that the ratio of 8-oxo-dG / dG in DNA is in- creased by more than 6 times in the transition from log phase of cell culture growth to stationary thus 8-oxo-dG be one of the biomarkers “stationary aging” culture. By add- ing exogenous 8-oxo-dG in the culture medium it is intensively absorbed by the cells. Cytotoxicity of 8-oxo-dG, when added to cells in the logarithmic growth phase was not observed in the concentration range 10 -6 -10 -3 M. At the same time, exogenous 8-oxo-dG in the middle and high concentrations resulted in a significant and reproducible reduc- tion in the content of 8-oxo-dG in DNA of cells of the stationary phase of growth. The ratio of 8-oxo-dG / dG falling under its influence in 5-6 times in comparison with con- trol, approaching the level typical for the cells in logarithmic growth phase. At the same time, the addition of exogenous 8-oxo-dG in the early stages of cultivation (growth - the beginning stationary phase) had no effect on its content in the DNA. Thus, the nature of exposure 8-oxo-dG cells strongly depends on its concentration in the medium and proliferative status of the culture. The experimental data clearly indicate the presence in 8-oxo-dG expressed biological effect. We assume that it can be associated with the activation of reparative and antioxidant systems without oxidative stress. 184 THE TENTH INTERNATIONAL CONFERENCE ON BIOINFORMATICS OF GENOME REGULATION AND STRUCTURE\SYSTEMS BIOLOGY MOLECULAR EVOLUTION ANALYSIS OF RNA-BINDING NIP7 PROTEIN FROM DEEP- AND SHALLOW-WATER ARCHAEA K.E. Medvedev*, D.A. Afonnikov Institute of Cytology and Genetics SB RAS, Novosibirsk, Russia * Corresponding author: albatros@bionet.nsc.ru Key words: Nip7 protein, SDP, extremophiles, high pressure, archaea, adaptation Motivation and Aim: Pressure and temperature are important environmental factors that determine many of the processes occurring in living organisms. The greatest interest is caused by organisms-extremophiles, which inhabited the ecosystems where conditions are not compatible with the lives of most of other organisms. Mechanisms to ensure survival of cells under such conditions are still not clear. Their understanding will help to answer some fundamental questions related to the origin of life and evolution of mi- croorganisms in its earlier stages and adaptation to conditions of different ecological systems. One of the effective approaches to study the adaptation of protein structures to extreme conditions is the comparative analysis of sequences. In current work we conduct a study of the molecular evolution of protein Nip7, which contributes to adaptation to life at high pressure and temperature. Methods and Algorithms: We used two programs to identify specific substitutions: multi- Harmony [1] and Zebra [2]. Results: First of all should be considered the results of the identification of specific pro- tein positions in relation to the depths of habitats of organisms. The number of signifi- cant positions that is common to both programs amounted to 19. In the case of the speci- ficity to the temperature, the number of significant specific positions for multi-Harmony was 72, for Zebra – 64 positions. The number of detected specific position in this case is much larger than in the analysis of specificity to pressure. The intersection of the results of two programs is also larger for temperature. Conclusion: It should be noted that the number of positions in which specific substi- tutions are associated with temperature more than three times exceeds the number of positions specific to pressure. Furthermore, their significance level (Z-statistics) for a significant part of these positions higher than the positions selected for specificity to the depths of habitat. The data obtained may reflect the fact that molecular adaptation to high temperatures in the Nip7 protein is more pronounced than the pressure, i.e. temperature is a factor in the selection to a greater extent than the pressure. Thus, the analysis showed that on the one hand, for positions in which substitutions can be specific way in relation to the depth habitats of the organisms for deep-sea organisms are more typical substitu- tions that increase the hydrophobicity of the residues from shallow-water organisms compared to deep-water. References: 1. W. Pirovano, K.A. Feenstra, J. Heringa. (2006) Sequence comparison by sequence harmony identifies subtype-specific functional sites. Nucl. Acids Res., 34:6540-6548. 2. D. Suplatov, E. Kirilin, V. Takhaveev, V. Švedas. (2014) Zebra: a web server for bioinformatic analysis of diverse protein families. JBSD, 32:1752-1758. 185 THE TENTH INTERNATIONAL CONFERENCE ON BIOINFORMATICS OF GENOME REGULATION AND STRUCTURE\SYSTEMS BIOLOGY HIGH TEMPERATURE AND PRESSURE INFLUENCE ON INTERDOMAIN INTERFACE OF THE NIP7 PROTEINS FROM P. ABYSSI AND P. FURIOSUS: MD SIMULATION RESEARCH K.E. Medvedev*, D.A. Afonnikov Institute of Cytology and Genetics SB RAS, Novosibirsk, Russia * Corresponding author: albatros@bionet.nsc.ru Key words: Interdomain interface, domain motions, high temperature, adaptation, Nip7 Motivation and Aim: Interaction between domains of the protein, as well as their rela- tive positions and movement relative to each other is essential for the stability of protein structure and normal functioning of a protein molecule. The feature of the movement of the domains may define the mechanism of enzymatic reactions. Therefore, the descrip- tion of this motion is an important task in the analysis of the structures and functions of multidomain proteins. In current work we provide the investigation of the influence of high pressure and temperature influence on change of two domains motion parameters of the Nip7 protein from deep-water (P. abyssi) and shallow-water (P. furiosus) archaea. Methods and Algorithms: We used DynDom [1] to analyze the changes in the parameters of the mutual orientation of the domains of protein Nip7 during MD simulation. Results: Obtained data showed that interdomain interfaces of P. abyssi and P. furiosus Nip7 proteins were formed by stable hydrophobic interactions. It is shown that increas- ing the pressure significantly influences the angle of rotation of the domains and increas- ing the temperature slightly reduces the value of the angle of rotation of the domains. The effect of temperature on translation along the axis has a different pattern for the two proteins. The analysis of the quantiles of the distribution showed that the increase of temperature shifts the distribution of the model parameter P. abyssi Nip7 in the direction of increasing, for the P. furiosus Nip7 in the direction of decreasing. Conclusion: In current work we propose an approach that allows us to analyze the mo- tion parameters of the protein domains during MD simulation. This approach implies a certain approximation that domains constitute a rigid structural subunit of protein struc- ture. This allows you to concentrate on the study of changes occurring in the interdomain space which have a significant impact on the entire structure. Analysis of the direction of movement of the domains showed that the domains of deep-water and shallow-water organisms Nip7 protein move differently. In addition, it is suggested that the type of mo- tion of domains under study is similar to the “shear motions”. References: 1. S. Hayward R.A. Lee. (2002). Improvements in the analysis of domain motions in proteins from con- formational change: DynDom version 1.50. J. Molecular Graphics Modelling, 21(3):181-183. 186 THE TENTH INTERNATIONAL CONFERENCE ON BIOINFORMATICS OF GENOME REGULATION AND STRUCTURE\SYSTEMS BIOLOGY SITEX 2.0: FUNCTIONAL SITES PROJECTION ON ALTERNATIVE SPLICED ISOFORMS AND HOMOLOGOUS GENES I.V. Medvedeva*, P.S. Demenkov, V.A. Ivanisenko Institute of Cytology and Genetics SB RAS, Novosibirsk, Russia * Corresponding author:brukaro@bionet.nsc.ru Key words: gene structure, protein functional sites, alternative splicing Motivation and Aim: The SitEx system stores information on projection of exon and domain boundaries, positions of functional sites on protein sequence and the coding sequence of the gene [1]. The functions of proteins and their domains are defined mostly by functional sites so they are highly conserved units of proteins. Protein functional sites variability is low that let us to project known protein functional site amino acids positions from one isoform to another, as well as to project them to orthologous and paralogous gene sequences. This information is applicable in the study of the structural– functional organization of the gene in evolutionary perspective and could help in design of novel proteins. Methods and Algorithms: This work presents update of SitEx system. The information about isoforms and homologous genes was extracted from Ensembl 82 release using public MySQL database. For protein functional site projection on other isoforms was used exon-to-exon blast alignment. To indicate function site amino acid in homologous genes we applied Clustal Omega with further checking for functional site amino acid position sequence environment. Previous SitEx version contained the information about PDB entries with 40% sequence similarity. We included every possible PDB entry in current release. Found homologous sequences are presented using alignments. We also integrated information about SNP from Ensembl and 1000 genomes projects, annotated sites from Catalytic Site Atlas. Results: Currently PDB contains about 120 000 structures. We obtained only 44 000 structures that have known protein functional sites from Eukaryota. These structures were connected to 6637 genes and 13034 transcripts from 41 species including animals, plants and fungi according to previously published pipeline [1]. There were discovered protein functional sites changes as the consequences of alternative splicing for only 5 genes. Conclusion: The developed system allows analyzing protein functional site in alterna- tive isoforms using 3D structures because the affinity of the sites could be changed. SitEx 2.0 also opens possibility to evaluate protein functional site preservation in ho- mologous sequences. Availability: http://www-bionet.sscc.ru/sitex/, MySQL dump of 2.0 release References: 1. Medvedeva I.V., Demenkov P.S., Kolchanov N.A., Ivanisenko V.A. (2012). SitEx: a computer system for analysis of projections of protein functional sites on eukaryotic genes. Nucleic Acids Res. Database issue:D278-83. 2. Medvedeva I.V., Demenkov P.S., Ivanisenko V.A. (2015) Computer analysis of protein functional sites projection on exon structure of genes in Metazoa. BMC Genomics. 16(Suppl 13):S2 187 THE TENTH INTERNATIONAL CONFERENCE ON BIOINFORMATICS OF GENOME REGULATION AND STRUCTURE\SYSTEMS BIOLOGY PROGRAM COMPLEX ICGENOMICS FOR ANALYSIS OF HIGH-THROUGHPUT SEQUENCING EXPERIMENTS I.V. Medvedeva 1 , A.O. Bragin 1 , K.V. Gunbin 1 , P.S. Demenkov 1 , O.V. Vishnevsky 1 , A.M. Spitsina 2 , F.M. Naumenko 2 , V.N. Babenko 1 , N.L. Podkolodnyy 1 , Y.L. Orlov 1 * Institute of Cytology and Genetics SB RAS, Novosibirsk, Russia Novosibirsk State University, Novosibirsk, Russia * Corresponding author: orlov@bionet.nsc.ru Key words: computer genomics, sequencing, program complex, data integration Motivation and Aim: The program complex ICGenomics has been designed for stor- age, mining, and analysis of high-throughput sequencing experiments [1]. ICGenomics enables wet-lab biologists to perform high-quality processing of data in the fields of ge- nomics, biomedicine, and biotechnology. They include novel methods of the processing of initial high-throughput sequencing data. Examples are: ChIP-seq analysis; functional annotation of gene regulatory regions in nucleotide sequences; prediction of nucleosome positioning; and structural and functional annotation of proteins, including prediction of their allergenicity parameters, as well as estimates of evolution changes in protein families. Applications of ICGenomics to the analysis of genomic sequences of the yeast, ChIP-seq data on the mouse and human are considered. Methods and Algorithms: We developed set of computer programs and have integrated them in program complex. ICGenomics implements both standard and modern methods for processing, analyzing, and visualizing sequencing data and functional annotation of genome regions. Results: The program complex ICGenomics allows to fulfill the following distinct func- tions: (1) processing of extended nucleotide sequences from next generation sequencing data including; (2) annotation of genomic sequences including exon search, and predic- tion of miRNA gene promoters using specific nucleotide structure motifs; (3) predic- tion protein allergenicity by their structural and functional properties using functional annotation of protein spatial structure; (4) research of evolution modes of protein cod- ing genes, including reconstruction of evolutionary history of proteins on the basis of ortholog prediction in sequenced genomes; the phylogenetic analysis and investigation of selection modes. Conclusion: Evolutionary history of proteins reconstruction is based on ortholog predic- tion in sequenced genomes. The component is realized in the form of the data processing pipe-line. New development of the system includes ChIP-seq analysis software [2]. Availability: The system is available at http://www-bionet.sscc.ru/icgenomics. References: 1. YL. Orlov et al. (2012) ICGenomics: program complex for symbol sequence analysis in genomics, Vavilov journal of genetics and breeding, 16(4/1): 732-741. (In Russian). 2. A.M. Spitsina et al. (2015) Supercomputer analysis of genomics and transcriptomics data revealed by high-throughput DNA sequencing, Program systems: theory and applications, 6:1(24): 157–174. (In Russian). 188 THE TENTH INTERNATIONAL CONFERENCE ON BIOINFORMATICS OF GENOME REGULATION AND STRUCTURE\SYSTEMS BIOLOGY NONTHERMAL IMPACT TERAHERTZ RADIATION ON THE LIVING SYSTEMS I.A. Mescheryakova 1 , E.V. Demidova 1 , T.N. Goryachkovskaya 1 , E.A. Demidov 1 , A.V. Bryanskaya 1 , S.V. Sergeeva 1 , S.L. Kiselev 3 , M.A. Lagarkova 3 , G.N. Kulipanov 2 , A.I. Semenov 2 , N.A. Vinokurov 2 , N.A. Kolchanov 1 , V.M. Popik 2 , S.E. Peltek 1 1 Institute of Cytology and Genetics SB RAS, Novosibirsk, Russia 2 Budker Institute of Nuclear Physics SB RAS, Novosibirsk, Russia 3 Vavilov Institute of General Genetics, RAS, Moscow, Russia Key words: evolution, genome, k-mer distribution Terahertz (THz) radiation was proposed recently for use in various applications, includ- ing medical imaging and security scanners. We studied the impact of terahertz radiation on E. coli biosensor cells containing plas- mids with promoters of stress-sensitive genes controlling the expression of GFP. GFP level was measured by fluorometry. The impact of terahertz radiation was nonthermal, i.e. special care was taken to keep specimen temperature at the 35±2 °С range during irradiation so that heat shock genes are not induced. We have found that terahertz radia- tion activates genes associated with oxidative stress response. Results of the Ames test and SOS-chromotest indicate that terahertz radiation produces neither mutagenic nor genotoxic effects. The exposure of E. coli cells under terahertz radiation causes increased expression of 14 genes of rapid response. Among these genes was glutamine synthetase gene (glnA). By using the glnA gene promoter we have designed biosensor sensitive to the effects of the terahertz radiation. Since human embryonic stem cells (hESCs) are extremely sensitive to environmental stimuli, we have therefore utilised this cell model to investigate the non-thermal effects of THz irradiation. We have studied DNA damage and transcriptome responses in hESCs exposed to the narrow-band THz radiation (2.3 THz) under strict temperature control. This work was supported by a grant from the Ministry of Education and Science of the Russian Federation (agreement № 14.616.21.0053 (RFMEFI61615X0053)). 189 THE TENTH INTERNATIONAL CONFERENCE ON BIOINFORMATICS OF GENOME REGULATION AND STRUCTURE\SYSTEMS BIOLOGY BIOMARKERS OF AGE IN THE “STATIONARY PHASE AGING” MODEL G.V. Morgunova*, D.S. Esipov, M.V. Marmiy, A.N. Khokhlov Evolutionary Cytogerontology Sector, School of Biology, Lomonosov Moscow State University, Moscow, Russia * Corresponding author: morgunova@mail.bio.msu.ru Key words: biomarkers of aging, senescence-associated β-galactosidase, cytogerontology, stationary phase aging, cell senescence, 8-oxo-2’-deoxyguanosine Motivation and Aim: Currently gerontologists search for biomarkers of aging (including cell aging) which can allow determining age of organism/cell quickly and easily. Se- nescence-associated beta-galactosidase (SA-β-Gal) remains the most popular biomarker of cell aging. Nowadays, another biomarker, 8-oxo-2’-deoxyguanosine (8-oxo-dG), is becoming popular in gerontology. We have investigated applicability of these markers to our “stationary phase aging” model, i.e. increase in the probability of dying for cultured cells upon retardation and subsequent complete cessation of their proliferation within one passage. Methods and Algorithms: Experiments were performed on transformed Chinese hamster cells (B11-dii FAF28 line, clone 237). The cells were cultivated for 14-15 days at 37°C in Carrel glass flasks using DMEM supplemented with 10% bovine serum and antibiotics. In the first series of experiments on the 4th, 8th, and 15th day con- tents of 8-oxo-dG and dG in DNA hydrolyzate were analyzed chromatographically using Beckman-Gold chromatograph (USA) at a wavelength of 254 nm. In the second series of experiments on the 7th and 14th day the cells were fixed for 3-5 minutes in 2% form- aldehyde and 0.2% glutaraldehyde and incubated with X-Gal for 12-16 hours at 37°C. Results: It was found that the ratio of 8-oxo-dG/dG increased with the “age” of cell culture. On the 15th day the cells became to die and the ratio had significantly increased (22.40·10 -5 ) compared to this index on the 4th (6.26·10 -5 ) and on the 8th (4.42·10 -5 ) days when the cells had reached monolayer and gone into the stationary phase of growth. It was also found that 14-day-old culture had much higher percentage of cells staining for SA-β-Gal than the «young» (7-day-old) cells. Conclusion: Thus, 8-охо-dG accu- mulates in the stationary phase aging culture of Chinese hamster cells as evidenced by a significant increase in the ratio of 8-oxo-dG/dG in DNA of the cells on the 15th day. Consequently, it is possible to predict an increase in the probability of death in the cell culture evaluating expression of this biomarker. Furthermore, stationary phase aged cells express SA-β-Gal demonstrating a good correlation of this parameter with “age” of cell culture. We believe that both methods can be used to determine the biological age of cells in testing of new potential geroprotectors. 190 THE TENTH INTERNATIONAL CONFERENCE ON BIOINFORMATICS OF GENOME REGULATION AND STRUCTURE\SYSTEMS BIOLOGY k-MER FREQUENCY DISTRIBUTION OF EUKARYOTIC PROTEOMES A.A. Morozov 1 * Limnological Institute SB RAS, Irkutsk, Russia * Corresponding author: morozov@lin.irk.ru Motivation & aims:There is a body of work regarding k-mer frequency analysis in DNA sequences. It was shown earlier that such distribution is species-specific and can be used for short sequence classification eg in metagenomic projects. In this work I show that the same is true for aminoacid sequences, and attempt to assess some of the factors that could influence the specificity of k-mer distribution. Methods & algorithms: Two datasets were used: the CEGMA collection of highly con- servative homologous housekeeping genes of six model eukaryotes (A. thaliana, C. ele- gans, D. melanogaster, H. sapiens, S. cerevisiae and S. pombe), and complete proteomes of the same six species. UNIPROT annotations for structural and functional elements of proteins were used. The sequences were classified using naïve Bayes classifier with k-mer frequencies as features. 90% of sequences in each dataset were randomly selected for training the clas- sifier, and the remaining 10% were classified. Calculations were performed in pure Py- thon. For comparing the distributions, euclidean distances were calculated using only the frequencies of k-mers present at least once in both distributions. Results: The specificity of the analysis varied for the different genomes and values of k, but typically it was from 30% to 80%. For most of the genomes specificity peaked at k values of 5 or 6, unlike optimal k for DNA-based analyses which was shown to be between 10 and 15 nucleotides in various earlier works. The next question is whether factors that shape the k-mer distribution specificity, what- ever they may be, apply to the entire protein or are restricted only to some of its parts. If there indeed are such parts, their k-mer distributions will be more different from each other than those of sequences as a whole. If, on the opposite, some subsequences were under lesser influence of k-mer shaping factors, their distributions in different proteomes will be more similar. To test this hypothesis, I have build proteome-specific distributions for a series of features. Distances were calculated between these distributions and the universal distributions for the same features, built using all the species in the datasets. Distribution of distances is approximately the same for both complete protein sequences and structural features (helices, beta-strands, transmembrane domains). It allows to as- sume that these structural features have no specificity in terms of k-mer composition. The same is true for entire annotated domains and non-domain subsequences, which means that k-mer specificity is not, in general, affected by sequences’ functional status. Conclusion: k-mer distributions were shown to be proteome-specific. No hypotheses can be made regarding the reasons of this phenomenon, but it was shown that it applies to a significant portion of proteins within proteome and to the entire protein sequences. 191 THE TENTH INTERNATIONAL CONFERENCE ON BIOINFORMATICS OF GENOME REGULATION AND STRUCTURE\SYSTEMS BIOLOGY CAN LONG ANTIPARALLEL OPEN READING FRAMES BE ENCODING ESSENTIAL GENES IN PROKARYOTIC GENOMES? D.M. Moshensky*, A.V. Alexeevski A.N. Belozersky Institute of Physico-Chemical Biology MSU, Moscow, Russia * Corresponding author: moshenskydenis@gmail.com Download 3.91 Kb. Do'stlaringiz bilan baham: |
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