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Toshio Ota

Publications and source records attributed to Toshio Ota.

11 recordsLinked to original sources

Diversification of transcriptional modulation: large-scale identification and characterization of putative alternative promoters of human genes.

By analyzing 1,780,295 5'-end sequences of human full-length cDNAs derived from 164 kinds of oligo-cap cDNA libraries, we identified 269,774 independent positions of transcriptional start sites (TSSs) for 14,628 human RefSeq genes. These TSSs were clustered into 30,964 clusters that were separated from each other by more than 500 bp and thus are very likely to constitute mutually distinct alternative promoters. To our surprise, at least 7674 (52%) human RefSeq genes were subject to regulation by putative alternative promoters (PAPs). On average, there were 3.1 PAPs per gene, with the composition of one CpG-island-containing promoter per 2.6 CpG-less promoters. In 17% of the PAP-containing loci, tissue-specific use of the PAPs was observed. The richest tissue sources of the tissue-specific PAPs were testis and brain. It was also intriguing that the PAP-containing promoters were enriched in the genes encoding signal transduction-related proteins and were rarer in the genes encoding extracellular proteins, possibly reflecting the varied functional requirement for and the restricted expression of those categories of genes, respectively. The patterns of the first exons were highly diverse as well. On average, there were 7.7 different splicing types of first exons per locus partly produced by the PAPs, suggesting that a wide variety of transcripts can be achieved by this mechanism. Our findings suggest that use of alternate promoters and consequent alternative use of first exons should play a pivotal role in generating the complexity required for the highly elaborated molecular systems in humans.

Base Sequence↗

Signal sequence and keyword trap in silico for selection of full-length human cDNAs encoding secretion or membrane proteins from oligo-capped cDNA libraries.

We have developed an in silico method of selection of human full-length cDNAs encoding secretion or membrane proteins from oligo-capped cDNA libraries. Fullness rates were increased to about 80% by combination of the oligo-capping method and ATGpr, software for prediction of translation start point and the coding potential. Then, using 5'-end single-pass sequences, cDNAs having the signal sequence were selected by PSORT ('signal sequence trap'). We also applied 'secretion or membrane protein-related keyword trap' based on the result of BLAST search against the SWISS-PROT database for the cDNAs which could not be selected by PSORT. Using the above procedures, 789 cDNAs were primarily selected and subjected to full-length sequencing, and 334 of these cDNAs were finally selected as novel. Most of the cDNAs (295 cDNAs: 88.3%) were predicted to encode secretion or membrane proteins. In particular, 165(80.5%) of the 205 cDNAs selected by PSORT were predicted to have signal sequences, while 70 (54.2%) of the 129 cDNAs selected by 'keyword trap' preserved the secretion or membrane protein-related keywords. Many important cDNAs were obtained, including transporters, receptors, and ligands, involved in significant cellular functions. Thus, an efficient method of selecting secretion or membrane protein-encoding cDNAs was developed by combining the above four procedures.

5' Flanking Region↗

Integrative annotation of 21,037 human genes validated by full-length cDNA clones.

The human genome sequence defines our inherent biological potential; the realization of the biology encoded therein requires knowledge of the function of each gene. Currently, our knowledge in this area is still limited. Several lines of investigation have been used to elucidate the structure and function of the genes in the human genome. Even so, gene prediction remains a difficult task, as the varieties of transcripts of a gene may vary to a great extent. We thus performed an exhaustive integrative characterization of 41,118 full-length cDNAs that capture the gene transcripts as complete functional cassettes, providing an unequivocal report of structural and functional diversity at the gene level. Our international collaboration has validated 21,037 human gene candidates by analysis of high-quality full-length cDNA clones through curation using unified criteria. This led to the identification of 5,155 new gene candidates. It also manifested the most reliable way to control the quality of the cDNA clones. We have developed a human gene database, called the H-Invitational Database (H-InvDB; http://www.h-invitational.jp/). It provides the following: integrative annotation of human genes, description of gene structures, details of novel alternative splicing isoforms, non-protein-coding RNAs, functional domains, subcellular localizations, metabolic pathways, predictions of protein three-dimensional structure, mapping of known single nucleotide polymorphisms (SNPs), identification of polymorphic microsatellite repeats within human genes, and comparative results with mouse full-length cDNAs. The H-InvDB analysis has shown that up to 4% of the human genome sequence (National Center for Biotechnology Information build 34 assembly) may contain misassembled or missing regions. We found that 6.5% of the human gene candidates (1,377 loci) did not have a good protein-coding open reading frame, of which 296 loci are strong candidates for non-protein-coding RNA genes. In addition, among 72,027 uniquely mapped SNPs and insertions/deletions localized within human genes, 13,215 nonsynonymous SNPs, 315 nonsense SNPs, and 452 indels occurred in coding regions. Together with 25 polymorphic microsatellite repeats present in coding regions, they may alter protein structure, causing phenotypic effects or resulting in disease. The H-InvDB platform represents a substantial contribution to resources needed for the exploration of human biology and pathology.

Alternative Splicing↗

Mood profile evaluation by families, young physicians and experienced psychiatrists in an actual clinical practice setting.

The purpose of this study was to explore differences in mood profile evaluation between raters with different backgrounds. Special emphasis was placed on expertise factor, influence of mood categories, and patient heterogeneity in a clinical setting. We administered Profile of Mood Scale (POMS) to patients' families, residents, and experienced psychiatrists as well as the patients, asking them to make an evaluation based on their image of the patients' subjective mood experience. Subscale scores and within-case across-item agreement indices among the raters were submitted for analysis. Analysis of variance of the subscale score showed significant effects of the rater by subscale-category and the rater by case components. The former was most influenced by the Vigor/Activity subscale in which the families and patients had higher scores than the physicians. As for rater-to-patient correlations of the score, psychiatrists were superior to residents in Anger/Hostility and Fatigue/Inertia, while families were superior to physicians in Vigor/Activity. These results suggest significance of expertise in mood evaluation as well as importance of time shared with the patients. The within-case across-item agreement data were subjected to cluster and canonical discriminant analysis. The analysis revealed four clusters which were best explained by two dimensions, one interpreted as general feasibility of evaluation and the other as characteristic emotional expression which caused separation of evaluation between families and physicians. Rater's expertise is a significant factor. Attention should also be paid to mood categories and patient heterogeneity.

Analysis of Variance↗

[Seizures].

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Aged↗

Complete sequencing and characterization of 21,243 full-length human cDNAs.

As a base for human transcriptome and functional genomics, we created the "full-length long Japan" (FLJ) collection of sequenced human cDNAs. We determined the entire sequence of 21,243 selected clones and found that 14,490 cDNAs (10,897 clusters) were unique to the FLJ collection. About half of them (5,416) seemed to be protein-coding. Of those, 1,999 clusters had not been predicted by computational methods. The distribution of GC content of nonpredicted cDNAs had a peak at approximately 58% compared with a peak at approximately 42%for predicted cDNAs. Thus, there seems to be a slight bias against GC-rich transcripts in current gene prediction procedures. The rest of the cDNAs unique to the FLJ collection (5,481) contained no obvious open reading frames (ORFs) and thus are candidate noncoding RNAs. About one-fourth of them (1,378) showed a clear pattern of splicing. The distribution of GC content of noncoding cDNAs was narrow and had a peak at approximately 42%, relatively low compared with that of protein-coding cDNAs.

Chromosomes, Human, 21-22 and Y↗

Salusins: newly identified bioactive peptides with hemodynamic and mitogenic activities.

The discovery of endogenous bioactive peptides has typically required a lengthy identification process. Computer-assisted analysis of cDNA and genomic DNA sequence information can markedly shorten the process. A bioinformatic analysis of full-length, enriched human cDNA libraries searching for previously unidentified bioactive peptides resulted in the identification and characterization of two related peptides of 28 and 20 amino acids, which we designated salusin-alpha and salusin-beta. Salusins are translated from an alternatively spliced mRNA of TOR2A, a gene encoding a protein of the torsion dystonia family. Intravenous administration of salusin-alpha or salusin-beta to rats causes rapid, profound hypotension and bradycardia. Salusins increase intracellular Ca2+, upregulate a variety of genes and induce cell mitogenesis. Salusin-beta stimulates the release of arginine-vasopressin from rat pituitary. Expression of TOR2A mRNA and its splicing into preprosalusin are ubiquitous, and immunoreactive salusin-alpha and salusin-beta are detected in many human tissues, plasma and urine, suggesting that salusins are endocrine and/or paracrine factors.

Adenosine Triphosphatases↗

cDNA macroarray analysis of gene expression in synoviocytes stimulated with TNFalpha.

Gene expression of synoviocytes stimulated with tumor necrosis factor-alpha (TNFalpha) was studied by macroarray analysis to elucidate the cellular response and identify new biological functions of known and unknown genes. 10035 cDNA clones were used to make cDNA macroarrays of representative genes. Synoviocytes expressed large amounts of fibronectin and collagen mRNA. Statistical analysis of the macroarray data revealed 26 genes, including six new genes, which underwent significant alteration of gene expression in response to TNFalpha stimulation. These findings suggest that the synoviocyte response to TNFalpha stimulation forms the basis of development of various aspects of the pathophysiology of rheumatoid arthritis.

Amino Acid Sequence↗

Transcriptome analysis of acetate metabolism in Corynebacterium glutamicum using a newly developed metabolic array.

Following the determination of the whole-genome sequence of Corynebacterium glutamicum, we have developed a DNA array to extensively investigate gene expression and regulation relevant to carbon metabolism. For this purpose, a total of 120 C. glutamicum genes, including those in central metabolism and amino acid biosyntheses, were amplified by PCR and printed onto glass slides. The resulting array, designated a "metabolic array", was used for hybridization with fluorescently labeled cDNA probes generated by reverse transcription from total RNA samples. As the first demonstration of transcriptome analysis in this industrially important microorganism, we applied the metabolic array to study differential transcription profiles between cells grown on glucose and on acetate as the sole carbon source. The changes in gene expression observed for the known acetate-regulated genes (aceA, aceB, pta, and ack) were well consistent with the literature data of northern analyses and enzyme assays, indicating the utility of the metabolic array in transcriptome analysis of C. glutamicum. In addition to the known responses, many previously unrecognized co-regulated genes were identified. For example, several TCA cycle genes, such as gltA, sdhA, sdhB, fumH, and mdh, and the gluconeogenic gene pck were up-regulated in the acetate medium. On the other hand, a few genes involved in glycolysis and the pentose phosphate pathway, as well as many amino acid biosynthetic genes, were down-regulated in acetate. Furthermore, two gap genes, gapA and gapB, were found to be inversely regulated, suggesting the presence of a new regulatory step for carbon metabolism between glycolysis and gluconeogenesis.

Acetates↗

Database and analysis system for cDNA clones obtained from full-length enriched cDNA libraries.

We have developed an efficient sequence-analysis system and a database system for clones obtained from full-length enriched cDNA libraries made by using the oligo-capping method. We developed a semi-automatic analysis system for 5'- and 3'-end sequences. It pre-processes raw sequences (vector cut and accurate-sequence region extraction), clusters the sequences, searches for similarities through public databases, annotates completeness of clones and analyzes the ORFs in the sequences. Newly developed or improved programs are used in each step. A new program, ESTiMateFull is used to evaluate and to predict the sequence-fullness based on comparisons with mRNA and EST sequences, respectively. The ATGpr program is used to predict sequence-fullness based on statistical information. The combination of full-length enriched cDNA clones and ATGpr fullness prediction resulted in 70% accuracy in the specificity and the sensitivity of the fullness predictions. For the ORFs predicted by the ATGpr, the signal peptides are predicted and a motif search is performed by our new system. We also developed a program that assembles our sequences with dbEST sequences and developed a system to retrieve clones by the characteristics of the ORFs. As keywords, combination of various results of the analyses can be used for retrieval. And various results such as ORF features and database search results can be shown on the same screen by multiple displays. Full-length clones having interesting functions can thus be retrieved efficiently by using this system.

Amino Acid Sequence↗