Details of a Researcher - Tomita, Masaru

Papers - Tomita, Masaru

Division display 301 - 320 of about 520 ／ All the affair displays >>

G-language genome analysis environment with REST and SOAP web service interfaces

Arakawa, K., Kido, N., Oshita, K. and Tomita, M.

Nucleic Acids Res. (Nucleic Acids Research) 38 ( SUPPL. 2 ) W700–W705 - 5 2010

Research paper (scientific journal), Joint Work, Accepted, ISSN 03051048

G-language genome analysis environment (G-language GAE) contains more than 100 programs that focus on the analysis of bacterial genomes, including programs for the identification of binding sites by means of information theory, analysis of nucleotide composition bias and the distribution of particular oligonucleotides, calculation of codon bias and prediction of expression levels, and visualization of genomic information. We have provided a collection of web services for these programs by utilizing REST and SOAP technologies. The REST interface, available at http://rest.glanguage. org/, provides access to all 145 functions of the G-language GAE. These functions can be accessed from other online resources. All analysis functions are represented by unique universal resource identifiers. Users can access the functions directly via the corresponding universe resource locators (URLs), and biological web sites can readily embed the functions by simply linking to these URLs. The SOAP services, available at http://www.g-language.org/wiki/soap/, provide language-independent programmatic access to 77 analysis programs. The SOAP service Web Services Definition Language file can be readily loaded into graphical clients such as the Taverna workbench to integrate the programs with other services and workflows. © The Author(s) 2010. Published by Oxford University Press.

Access to Document (DOI)

Collective Dynamics of Specific Gene Ensembles Crucial for Neutrophil Differentiation: The Existence of Genome Vehicles Revealed

Tsuchiya, M., Piras, V., Giuliani, A., Tomita, M. and Selvarajoo

PLoS One (PLoS ONE) 5 ( 8 ) e12116 2010

Research paper (scientific journal), Joint Work, Accepted

Cell fate decision remarkably generates specific cell differentiation path among the multiple possibilities that can arise through the complex interplay of high-dimensional genome activities. The coordinated action of thousands of genes to switch cell fate decision has indicated the existence of stable attractors guiding the process. However, origins of the intracellular mechanisms that create "cellular attractor" still remain unknown. Here, we examined the collective behavior of genome-wide expressions for neutrophil differentiation through two different stimuli, dimethyl sulfoxide (DMSO) and alltrans- retinoic acid (atRA). To overcome the difficulties of dealing with single gene expression noises, we grouped genes into ensembles and analyzed their expression dynamics in correlation space defined by Pearson correlation and mutual information. The standard deviation of correlation distributions of gene ensembles reduces when the ensemble size is increased following the inverse square root law, for both ensembles chosen randomly from whole genome and ranked according to expression variances across time. Choosing the ensemble size of 200 genes, we show the two probability distributions of correlations of randomly selected genes for atRA and DMSO responses overlapped after 48 hours, defining the neutrophil attractor. Next, tracking the ranked ensembles' trajectories, we noticed that only certain, not all, fall into the attractor in a fractal-like manner. The removal of these genome elements from the whole genomes, for both atRA and DMSO responses, destroys the attractor providing evidence for the existence of specific genome elements (named "genome vehicle") responsible for the neutrophil attractor. Notably, within the genome vehicles, genes with low or moderate expression changes, which are often considered noisy and insignificant, are essential components for the creation of the neutrophil attractor. Further investigations along with our findings might provide a comprehensive mechanistic view of cell fate decision. © 2010 Tsuchiya et al.

Access to Document (DOI)

Large-scale tRNA intron transposition in the archaeal order Thermoproteales represents a novel mechanism of intron gain

Fujishima, K., Sugahara, J., Tomita, M. and Kanai, A.

Mol. Biol. Evol. (Molecular Biology and Evolution) 27 ( 10 ) 2233–2243 - 2243 2010

Research paper (scientific journal), Joint Work, Accepted, ISSN 07374038

Recently, diverse arrangements of transfer RNA (tRNA) genes have been found in the domain Archaea, in which the tRNA is interrupted by a maximum of three introns or is even fragmented into two or three genes. Whereas most of the eukaryotic tRNA introns are inserted strictly at the canonical nucleotide position (37/38), archaeal intron-containing tRNAs have a wide diversity of small tRNA introns, which differ in their numbers and locations. This feature is especially pronounced in the archaeal order Thermoproteales. In this study, we performed a comprehensive sequence comparison of 286 tRNA introns and their genes in seven Thermoproteales species to clarify how these introns have emerged and diversified during tRNA gene evolution. We identified 46 intron groups containing sets of highly similar sequences (>70%) and showed that 16 of them contain sequences from evolutionarily distinct tRNA genes. The phylogeny of these 16 intron groups indicates that transposition events have occurred at least seven times throughout the evolution of Thermoproteales. These findings suggest that frequent intron transposition occurs among the tRNA genes of Thermoproteales. Further computational analysis revealed limited insertion positions and corresponding amino acid types of tRNA genes. This has arisen because the bulge-helix-bulge splicing motif is required at the newly transposed position if the pre-tRNA is to be correctly processed. These results clearly demonstrate a newly identified mechanism that facilitates the late gain of short introns at various noncanonical positions in archaeal tRNAs. © 2010 The Author.

Access to Document (DOI)

A Metabolic Model of Human Erythrocytes: Practical Application of the E-Cell Simulation Environment

Yachie, A. K., Nishino, T., Shimo, H., Suematsu, M., and Tomita, M.

J. Biomed. Biotechnol. (Journal of Biomedicine and Biotechnology) 2010 642420 2010

Research paper (scientific journal), Joint Work, Accepted, ISSN 11107243

The human red blood cell (RBC) has long been used for modeling of complex biological networks, for elucidation of a wide variety of dynamic phenomena, and for understanding the fundamental topology of metabolic pathways. Here, we introduce our recent work on an RBC metabolic model using the E-Cell Simulation Environment. The model is sufficiently detailed to predict the temporal hypoxic response of each metabolite and, at the same time, successfully integrates modulation of metabolism and of the oxygen transporting capacity of hemoglobin. The model includes the mechanisms of RBC maintenance as a single cell system and the functioning of RBCs as components of a higher order system. Modeling of RBC metabolism is now approaching a fully mature stage of realistic predictions at the molecular level and will be useful for predicting conditions in biotechnological applications such as long-term cold storage of RBCs. Copyright © 2010 Ayako Yachie-Kinoshita et al.

Access to Document (DOI)

Unbiased quantitation of Escherichia coli membrane proteome using phase-transfer surfactants

Masuda,T., Saito, N., Tomita, M. and Ishihama, M.

Mol Cell Proteomics. (Molecular and Cellular Proteomics) 8 ( 12 ) 2770-2777 - 2777 2009.12

Research paper (scientific journal), Joint Work, Accepted, ISSN 15359476

We developed a sample preparation protocol for rapid and unbiased analysis of the membrane proteome using an alimentary canal-mimicking system in which proteases are activated in the presence of bile salts. In this rapid and unbiased protocol, immobilized trypsin is used in the presence of deoxycholate and lauroylsarcosine to increase digestion efficiency as well as to increase the solubility of the membrane proteins. Using 22.5 μg of Escherichia coli whole cell lysate, we quantitatively demonstrated that membrane proteins were extracted and digested at the same level as soluble proteins without any solubility-related bias. The recovery of membrane proteins was independent of the number of transmembrane domains per protein. In the analysis of the membrane-enriched fraction from 22.5 μg of E. coli cell lysate, the abundance distribution of the membrane proteins was in agreement with that of the membrane protein-coding genes when this protocol, coupled with strong cation exchange prefractionation prior to nano-LC-MS/MS analysis, was used. Because this protocol allows unbiased sample preparation, protein abundance estimation based on the number of observed peptides per protein was applied to both soluble and membrane proteins simultaneously, and the copy numbers per cell for 1,453 E. coli proteins, including 545 membrane proteins, were successfully obtained. Finally, this protocol was applied to quantitative analysis of guanosine tetra- and pentaphosphate-dependent signaling in E. coli wild-type and relA knock-out strains. © 2009 by The American Society for Biochemistry and Molecular Biology, Inc.

Access to Document (DOI)

Identification of DNA-dependent protein kinase as a cofactor for the forkhead transcription factor FoxA2

Nock A., Ascano J.M., Jones T., Barrero M.J., Sugiyama N., Tomita M., Ishihama Y., Malik S.

Journal of Biological Chemistry (Journal of Biological Chemistry) 284 ( 30 ) 19915 - 19926 2009.07

ISSN 00219258

Forkhead factors are important regulators of animal development and homeostasis. They are among the earliest to bind quiescent genes, which they activate in conjunction with other transcription factors. Many liver-specific genes are under the control of FoxA2, a liver-enriched forkhead protein. Here we confirmed by chromatin immunoprecipitation that FoxA2 is one of the factors bound to the promoter-proximal enhancer of the gene encoding apolipoprotein AI (a component of high density lipoprotein) and that it functions in synergy with the nuclear receptor hepatocyte nuclear. Furthermore, toward identifying additional cofactors that could potentially regulate FoxA2 activity, we identified DNA-dependent protein kinase (DNA-PK) as a FoxA2-associated factor upon affinity purification of epitope-tagged FoxA2.Weshow that FoxA2, found to be a phosphoprotein in vivo, is also an efficient substrate for DNA-PK, which targets serine 283. This residue is contained within a conserved serine-glutamine phosphorylation signal for DNA-PK, located within the C-terminal third of the polypeptide, just distal to its winged-helix DNA binding domain. We establish that this residue is critical for FoxA2 function because FoxA2 bearing a mutation at this site is severely compromised in its ability to activate a reporter gene under the control of its cognate DNA-binding site (apoAI site B). Complementary experiments rule out that this mutation compromises the ability of FoxA2 to either translocate to the nucleus or to bind site B. We therefore conclude that DNA-PK-dependent phosphorylation of FoxA2 plays a critical role in its transcriptional activation function per se. © 2009 by The American Society for Biochemistry and Molecular Biology, Inc.

Access to Document (DOI)

Degradation of ppGpp by nudix pyrophosphatase modulates the transition of growth phase in the bacterium Thermus thermophilus

Ooga T., Ohashi Y., Kuramitsu S., Koyama Y., Tomita M., Soga T., Masui R.

Journal of Biological Chemistry (Journal of Biological Chemistry) 284 ( 23 ) 15549 - 15556 2009.06

ISSN 00219258

A major bacterial alarmone, guanosine 3′,5′-bispyrophosphate (ppGpp), controls cellular growth under conditions of nutritional starvation. For most bacteria, intracellular ppGpp levels are tightly controlled by the synthesis/degradation cycle of RelA and SpoT activities. This study shows a novel ppGpp regulatory protein governing the cellular growth of Thermus thermophilus, Ndx8, a member of the Nudix pyrophosphatase family that degrades ppGpp to yield guanosine 3′,5′-bisphosphate. The ndx8-null mutant strain exhibited early stage growth arrest accompanied by the stationary phase-specific morphologies and global transcriptional modulation under nutritionally defined conditions. Several possible substrate compounds of Ndx8, which specifically accumulated in the ndx8 mutant cells, were identified by employing a capillary electrophoresis time-of-flight mass spectrometry-based metabolomics approach. Among them, the hydrolytic activity of Ndx8 for ppGpp was significant not only in vitro but also in vivo. Finally, the elimination of ppGpp synthetic activity suppressed the observed phenotype of the ndx8 mutation, suggesting that the function of Ndx8 as a growth regulator is involved in ppGpp accumulation, which is thought to act as a trigger of the growth phase transition. These results suggest a novel mechanism of ppGpp-mediated growth control by the functional relay between Ndx8 and SpoT activity as ppGpp scavengers. © 2009 by The American Society for Biochemistry and Molecular Biology, Inc.

Access to Document (DOI)

Benzodiazepine and antidepressant use in elderly patients with anxiety disorders: a survey of 796 outpatients in Japan.

Uchida H, Suzuki T, Mamo DC, Mulsant BH, Kikuchi T, Takeuchi H, Tomita M, Watanabe K, Yagi G, Kashima H

Journal of anxiety disorders 23 ( 4 ) 477 - 81 2009.05

ISSN 0887-6185

Access to Document (DOI)

Characterization of a heat-stable enzyme possessing GTP-dependent RNA ligase activity from a hyperthermophilic archaeon, Pyrococcus furiosus

Kanai A., Sato A., Fukuda Y., Okada K., Matsuda T., Sakamoto T., Muto Y., Yokoyama S., Kawai G., Tomita M.

RNA 15 ( 3 ) 420 - 431 2009.03

ISSN 13558382

Using an expression protein library of a hyperthermophilic archaeon, Pyrococcus furiosus, we identified a gene (PF0027) that encodes a protein with heat-stable cyclic nucleotide phosphodiesterase (CPDase) activity. The PF0027 gene encoded a 21-kDa protein and an amino acid sequence that showed ∼27% identity to that of the 2′-5′ tRNA ligase protein, ligT (20 kDa), from Escherichia coli. We found that the purified PF0027 protein possessed GTP-dependent RNA ligase activity and that synthetic tRNA halves bearing 2′,3′-cyclic phosphate and 5′-OH termini were substrates for the ligation reaction in vitro. GTP hydrolysis was not required for the reaction, and GTPγS enhanced the tRNA ligation activity of PF0027 protein, suggesting that the ligation step is regulated by a novel mechanism. In comparison to the strong CPDase activity of the PF0027 protein, the RNA ligase activity itself was quite weak, and the ligation product was unstable during in vitro reaction. Finally, we used NMR to determine the solution structure of the PF0027 protein and discuss the implications of our results in understanding the role of the PF0027 protein. Copyright © 2009 RNA Society.

Access to Document (DOI)

Six classes of nuclear localization signals specific to different binding grooves of importin α

Kosugi S., Hasebe M., Matsumura N., Takashima H., Miyamoto-Sato E., Tomita M., Yanagawa H.

Journal of Biological Chemistry 284 ( 1 ) 478 - 485 2009.01

ISSN 00219258

The importin α/β pathway mediates nuclear import of proteins containing the classical nuclear localization signals (NLSs). Although the consensus sequences of the classical NLSs have been defined, there are still many NLSs that do not match the consensus rule and many nonfunctional sequences that match the consensus. We report here six different NLS classes that specifically bind to distinct binding pockets of importin α. By screening of random peptide libraries using an mRNA display, we selected peptides bound by importin α and identified six classes of NLSs, including three novel classes. Two noncanonical classes (class 3 and class 4) specifically bound the minor binding pocket of importin α, whereas the classical monopartite NLSs (class 1 and class 2) bound to the major binding pocket. Using a newly developed universal green fluorescent protein expression system, we found that these NLS classes, including plant-specific class 5 NLSs and bipartite NLSs, fundamentally require the regions outside the core basic residues for their activity and have specific residues or patterns that confer the activities differently between yeast, plants, and mammals. Furthermore, amino acid replacement analyses revealed that the consensus basic patterns of the classical NLSs are not essential for activity, thereby generating more unconventional patterns, including redox-sensitive NLSs. These results explain the causes of the NLS diversity. The defined consensus patterns and properties of importin α-dependent NLSs provide useful information for identifying NLSs. © 2009 by The American Society for Biochemistry and Molecular Biology, Inc.

Access to Document (DOI)

emPAI Calc -- for the estimation of protein abundance from largescale identification data by liquid chromatography-tandem massspectrometry

Shinoda, K., Tomita, M. and Ishihama,Y.

Bioinformatics (Bioinformatics) 26 ( 4 ) 576-577 - 577 2009

Research paper (scientific journal), Joint Work, Accepted, ISSN 13674803

Summary: emPAI Calc is an open-source web application for the estimation of protein abundance. It uses the correlation between the number of identified peptides and protein abundance in mass spectrometry-based proteomic experiments. The program is the first implementation of our previously reported emPAI algorithm; it calculates the emPAI from the protein identification results obtained by database search engines such as Mascot.™ Availability: http://empai.iab.keio.ac.jp/; http://empai.iab.keio.ac.jp/supplement.php Source codes are available under Mozilla Public License. Contact: y-ishi@ttck.keio.ac.jp Supplementary Information: Supplementary data are available at Bioinformatics online. © The Author 2009. Published by Oxford University Press.

Access to Document (DOI)

Measure of synonymous codon usage diversity among genes in bacteria

Suzuki, H., Saito, R. and Tomita, M

BMC Bioinformatics (BMC Bioinformatics) 10 167 2009

Research paper (scientific journal), Joint Work, Accepted

Background: In many bacteria, intragenomic diversity in synonymous codon usage among genes has been reported. However, no quantitative attempt has been made to compare the diversity levels among different genomes. Here, we introduce a mean dissimilarity-based index (Dmean) for quantifying the level of diversity in synonymous codon usage among all genes within a genome. Results: The application of Dmean to 268 bacterial genomes shows that in bacteria with extremely biased genomic G+C compositions there is little diversity in synonymous codon usage among genes. Furthermore, our findings contradict previous reports. For example, a low level of diversity in codon usage among genes has been reported for Helicobacter pylori, but based on Dmean, the diversity level of this species is higher than those of more than half of bacteria tested here. The discrepancies between our findings and previous reports are probably due to differences in the methods used for measuring codon usage diversity. Conclusion: We recommend that Dmean be used to measure the diversity level of codon usage among genes. This measure can be applied to other compositional features such as amino acid usage and dinucleotide relative abundance as a genomic signature. © 2009 Suzuki et al; licensee BioMed Central Ltd.

Access to Document (DOI)

Metabolomic Profiling of Anionic Metabolites by Capillary Electrophoresis Mass Spectrometry

Soga, T., Igarashi, K., Itoh, C., Mizobuchi, K., Zimmermann, H. P. and Tomita, M.

Analytical Chemistry (Analytical Chemistry) 81 ( 15 ) 6165-6174 - 6174 2009

Research paper (scientific journal), Joint Work, Accepted, ISSN 00032700

We describe a sheath flow capillary electrophoresis time-of-flight mass spectrometry (CE-TOFMS) method in the negative mode using a platinum electrospray ionization (ESI) spray needle, which allows the comprehensive analysis of anionic metabolites. The material of the spray needle had significant effect on the measurement of anions. A stainless steel spray needle was oxidized and corroded at the anodic electrode due to electrolysis. The precipitation of iron oxides (rust) plugged the capillary outlet, resulting in shortened capillary lifetime. Many anionic metabolites also formed complexes with the iron oxides or migrating nickel ion, which was also generated by electrolysis and moved toward the cathode (the capillary inlet). The metal-anion complex formation significantly reduced detection sensitivity of the anionic compounds. The use of a platinum ESI needle prevented both oxidation of the metals and needle corrosion. Sensitivity using the platinum needle increased from several- to 63-fold, with the largest improvements for anions exhibiting high metal chelating properties such as carboxylic acids, nucleotides, and coenzyme A compounds. The detection limits for most anions were between 0.03 and 0.87 μmol/L (0.8 and 24 fmol) at a signal-to-noise ratio of 3. This method is quantitative, sensitive, and robust, and its utility was demonstrated by the analysis of the metabolites in the central metabolic pathways extracted from mouse liver. © 2009 American Chemical Society.

Access to Document (DOI)

Systematic identification of cell cycle-dependent yeast nucleocytoplasmic shuttling proteins by prediction of composite motifs

Kosugi, S., Hasebe, M., Tomita, M. and Yanagawa, H.

Proc Natl Acad Sci U S A. (Proceedings of the National Academy of Sciences of the United States of America) 106 ( 31 ) 13142. - 10176 2009

Research paper (scientific journal), Joint Work, Accepted, ISSN 00278424

The cell cycle-dependent nucleocytoplasmic transport of proteins is predominantly regulated by CDK kinase activities; however, it is currently difficult to predict the proteins thus regulated, largely because of the low prediction efficiency of the motifs involved. Here, we report the successful prediction of CDK1-regulated nucleocytoplasmic shuttling proteins using a prediction system for nuclear localization signals (NLSs). By systematic amino acid replacement analyses in budding yeast, we created activity-based profiles for different classes of importin-α-dependent NLSs that represent the functional contributions of different amino acids at each position within an NLS class. We then developed a computer program for prediction of the classical importin-α/β pathway-specific NLSs (cNLS Mapper, available at http//nls-mapper.iab.keio.ac.jp/) that calculates NLS activities by using these profiles and an additivity-based motif scoring algorithm. This calculation method achieved significantly higher prediction accuracy in terms of both sensitivity and specificity than did current methods. The search for NLSs that overlap the consensus CDK1 phosphorylation site by using cNLS Mapper identified all previously reported and 5 previously uncharacterized yeast proteins (Yen1, Psy4, Pds1, Msa1, and Dna2) displaying CDK1- and cell cycle-regulated nuclear transport. CDK1 activated or repressed their nuclear import activity, depending on the position of CDK1-phosphorylation sites within NLSs. The application of this strategy to other functional linear motifs should be useful in systematic studies of protein-protein networks.

Access to Document (DOI)

Systematic phenome analysis of Escherichia coli multiple-knockout mutants reveals hidden reactions in central carbon metabolism

Nakahigashi, K., Toya, Y., Ishii, N., Soga, T., Hasegawa, M., Watanabe, H., Takai, Y., Honma, M., Mori, H. and Tomita, M.

Molecular Systems Biology 5 306 2009

Research paper (scientific journal), Joint Work, Accepted, ISSN 17444292

Central carbon metabolism is a basic and exhaustively analyzed pathway. However, the intrinsic robustness of the pathway might still conceal uncharacterized reactions. To test this hypothesis, we constructed systematic multiple-knockout mutants involved in central carbon catabolism in Escherichia coli and tested their growth under 12 different nutrient conditions. Differences between in silico predictions and experimental growth indicated that unreported reactions existed within this extensively analyzed metabolic network. These putative reactions were then confirmed by metabolome analysis and in vitro enzymatic assays. Novel reactions regarding the breakdown of sedoheptulose-7-phosphate to erythrose-4-phosphate and dihydroxyacetone phosphate were observed in transaldolase-deficient mutants, without any noticeable changes in gene expression. These reactions, triggered by an accumulation of sedoheptulose-7-phosphate, were catalyzed by the universally conserved glycolytic enzymes ATP-dependent phosphofructokinase and aldolase. The emergence of an alternative pathway not requiring any changes in gene expression, but rather relying on the accumulation of an intermediate metabolite may be a novel mechanism mediating the robustness of these metabolic networks. © 2009 EMBO and Macmillan Publishers Limited.

Access to Document (DOI)

A web server for interactive and zoomable Chaos Game Representation images

Arakawa, K., Oshita, K. and Tomita, M.

Source Code for Biology and Medicine (Source Code for Biology and Medicine) 4 6 2009

Research paper (scientific journal), Joint Work, Accepted

Chaos Game Representation (CGR) is a generalized scale-independent Markov transition table, which is useful for the visualization and comparative study of genomic signature, or for the study of characteristic sequence motifs. However, in order to fully utilize the scale-independent properties of CGR, it should be accessible through scale-independent user interface instead of static images. Here we describe a web server and Perl library for generating zoomable CGR images utilizing Google Maps API, which is also easily searchable for specific motifs. The web server is freely accessible at http://www.g-language.org/wiki/cgr/, and the Perl library as well as the source code is distributed with the G-language Genome Analysis Environment under GNU General Public License. © 2009 Arakawa et al; licensee BioMed Central Ltd.

Access to Document (DOI)

Modeling reaction-diffusion of molecules on surface and in volume spaces with the E-Cell System

Arjunan, S. N. V., and Tomita, M.

International Journal of Computer Science and Information Security 3 ( 1 ) 211-216 2009

Research paper (scientific journal), Joint Work, Accepted

Access to Document (DOI)

In silico modeling and metabolome analysis of long-stored erythrocytes to improve blood storage methods

Nishino, T., Yachie, A. K., Hirayama. A., Soga, T., Suematsu, T., and Tomita, M.

Journal of Biotechnology (Journal of Biotechnology) 144 ( 3 ) 212-223 - 223 2009

Research paper (scientific journal), Joint Work, Accepted, ISSN 01681656

There is currently no effective method for preventing ATP and 2,3-bisphosphoglycerate (2,3-BPG) depletion during long-term erythrocyte storage in the cold, although these metabolites are strongly associated with cell viability and oxygen delivery after transfusion. Metabolite reduction is caused by whole metabolic networks in the cell, which are regulated by various physical or chemical factors. Mathematical modeling is a powerful tool for integrating such complex and dynamic systems. Here, we developed a mathematical model to predict metabolism in erythrocytes preserved with a mannitol-adenine-phosphate solution (MAP) at 4 °C, by modifying a published model of large-scale erythrocyte metabolism. Our model successfully reproduced the reported decreases in ATP and 2,3-BPG during storage. Analysis of our model identified several enzymatic reactions and factors related to ATP and 2,3-BPG depletions, which may serve as possible targets for improving blood storage methods. We also performed metabolome analysis of laboratory-made MAP-stored erythrocytes using capillary electrophoresis time-of-flight mass spectrometry (CE-TOFMS), which provided a comprehensive view of the metabolism dynamics. Alterations in the metabolic intermediate concentrations after long storage were qualitatively predicted by the model. Finally, through further systematic analysis, we also discuss the usability of our model. © 2009 Elsevier B.V. All rights reserved.

Access to Document (DOI)

Pathway Projector: Web-based Zoomable Pathway Browser using KEGG Atlas and Google Maps API

Kono, N., Arakawa, K., Ogawa, R., Kido, N., Oshita, K., Ikegami, K., Tamaki, S. and Tomita, M.

PLoS ONE (PLoS ONE) 4 ( 11 ) e7710 2009

Research paper (scientific journal), Joint Work, Accepted

Background: Biochemical pathways provide an essential context for understanding comprehensive experimental data and the systematic workings of a cell. Therefore, the availability of online pathway browsers will facilitate post-genomic research, just as genome browsers have contributed to genomics. Many pathway maps have been provided online as part of public pathway databases. Most of these maps, however, function as the gateway interface to a specific database, and the comprehensiveness of their represented entities, data mapping capabilities, and user interfaces are not always sufficient for generic usage. Methodology/Principal Findings: We have identified five central requirements for a pathway browser: (1) availability of large integrated maps showing genes, enzymes, and metabolites; (2) comprehensive search features and data access; (3) data mapping for transcriptomic, proteomic, and metabolomic experiments, as well as the ability to edit and annotate pathway maps; (4) easy exchange of pathway data; and (5) intuitive user experience without the requirement for installation and regular maintenance. According to these requirements, we have evaluated existing pathway databases and tools and implemented a web-based pathway browser named Pathway Projector as a solution. Conclusions/Significance: Pathway Projector provides integrated pathway maps that are based upon the KEGG Atlas, with the addition of nodes for genes and enzymes, and is implemented as a scalable, zoomable map utilizing the Google Maps API. Users can search pathway-related data using keywords, molecular weights, nucleotide sequences, and amino acid sequences, or as possible routes between compounds. In addition, experimental data from transcriptomic, proteomic, and metabolomic analyses can be readily mapped. Pathway Projector is freely available for academic users at http://www.g-language.org/PathwayProjector/. © 2009 Kono et al.

Access to Document (DOI)

Disrupted tRNA Gene Diversity and Possible Evolutionary Scenarios

Sugahara, J., Fujishima, K., Morita, K., Tomita, M. and Kanai , A.

Journal of Molecular Evolution (Journal of Molecular Evolution) 69 ( 5 ) 497-504 - 504 2009

Research paper (scientific journal), Joint Work, Accepted, ISSN 00222844

The following unusual tRNAs have recently been discovered in the genomes of Archaea and primitive Eukaryota: multiple-intron-containing tRNAs, which have more than one intron; split tRNAs, which are produced from two pieces of RNA transcribed from separate genes; tri-split tRNAs, which are produced from three separate genes; and permuted tRNA, in which the 5′ and 3′ halves are encoded with permuted orientations within a single gene. All these disrupted tRNA genes can form mature contiguous tRNA, which is aminoacylated after processing by cis or trans splicing. The discovery of such tRNA disruptions has raised the question of when and why these complex tRNA processing pathways emerged during the evolution of life. Many previous reports have noted that tRNA genes contain a single intron in the anticodon loop region, a feature common throughout all three domains of life, suggesting an ancient trait of the last universal common ancestor. In this context, these unique tRNA disruptions recently found only in Archaea and primitive Eukaryota provide new insight into the origin and evolution of tRNA genes, encouraging further research in this field. In this paper, we summarize the phylogeny, structure, and processing machinery of all known types of disrupted tRNAs and discuss possible evolutionary scenarios for these tRNA genes. © 2009 Springer Science+Business Media, LLC.

Access to Document (DOI)

　 Previous page - Next page 　