PubMed Health⌕ Search

Biomedical subjects

Shinya Watanabe

Publications and source records attributed to Shinya Watanabe.

27 records · Page 2Linked to original sources
PubMed2004

Major human cytomegalovirus structural protein pp65 (ppUL83) prevents interferon response factor 3 activation in the interferon response.

We have identified a cytomegalovirus virion protein capable of modulating the rapid induction of an interferon-like response in cells that follows virus binding and penetration. Functional genomics revealed a role for the major cytomegalovirus structural protein, pp65 (ppUL83), in counteracting this response. The underlying mechanism involves a differential impact of this structural protein on the regulation of interferon response factor 3 (IRF-3). In contrast, NF-kappaB is activated independent of pp65, and neither STAT1 nor STAT3 becomes activated by either virus. pp65 is sufficient to prevent the activation of IRF-3 when introduced alone into cells. pp65 acts by inhibiting nuclear accumulation of IRF-3 and is associated with a reduced IRF-3 phosphorylation state. Thus, this investigation shows that the major structural protein of cytomegalovirus is committed to the modulation of the IRF-3 response, a primary mediator of the type I interferon response. By subverting IRF-3, the virus escapes throwing a central alarm devoted to both immediate antiviral control and regulation of the immune response.

Cells, Cultured↗
PubMed2004

Epstein-Barr virus nuclear antigen leader protein induces expression of thymus- and activation-regulated chemokine in B cells.

Epstein-Barr virus (EBV) nuclear antigen leader protein (EBNA-LP) plays a critical role in transformation of primary B lymphocytes to continuously proliferating lymphoblastoid cell lines (LCLs). To identify cellular genes in B cells whose expression is regulated by EBNA-LP, we performed microarray expression profiling on an EBV-negative human B-cell line, BJAB cells, that were transduced by a retroviral vector expressing the EBV EBNA-LP (BJAB-LP cells) and on BJAB cells that were transduced with a control vector (BJAB-vec cells). Microarray analysis led to the identification of a cellular gene encoding the CC chemokine TARC as a novel target gene that was induced by EBNA-LP. The levels of TARC mRNA expression and TARC secretion were significantly up-regulated in BJAB-LP compared with BJAB-vec cells. Induction of TARC was also observed when a subline of BJAB cells was converted by a recombinant EBV. Among the EBV-infected B-cell lines with the latency III phenotype that were tested, the LCLs especially secreted significantly high levels of TARC. The level of TARC secretion appeared to correlate with the level of full-length EBNA-LP expression. These results indicate that EBV infection induces TARC expression in B cells and that EBNA-LP is one of the viral gene products responsible for the induction.

Animals↗
PubMed2004

[Transcriptome analysis of virus-infected cells].

Human genome project revealed that human genes are derived from 30,000-40,000 species of genetic loci, which had been estimated as approximately 100,000. The project also promoted devising novel tools that enable us to analyze biological phenomena comprehensively. Microarray technology is a representative of the novel tools in genomics and engages us to explore genome-wide expression levels of genes simultaneously (transcriptome analysis). Here we show transcriptomes obtained from 10 species of cells infected with human cytomegalovirus, as a model virus, by a synthetic DNA microarray system that we have established recently. Our system provides simultaneous and parallel description on alteration of expression of viral and host genes that are represented within a single area on a slide glass. Moreover, we propose a project entitled 'comparative virology on cellular responses of infected hosts' that consists of multiple acquisition and integration of transcriptomes from a combination of several cells and viruses as a panel on the identical platform. The attempt should extract a novel concept in virology from investigation on differences and similarities among influence of a virus on a variety of different cells and conversely among responses of a species of cells against a variety of different viruses.

Cytomegalovirus↗
PubMed2003

A tetraspanin-family protein, T-cell acute lymphoblastic leukemia-associated antigen 1, is induced by the Ewing's sarcoma-Wilms' tumor 1 fusion protein of desmoplastic small round-cell tumor.

Recurrent chromosomal translocations in neoplasms often generate hybrid genes that play critical roles in tumorigenesis. Desmoplastic small round-cell tumor (DSRCT) is an aggressive malignancy associated with the chromosomal translocation t(11;22)(p13;q12). This translocation generates a chimeric transcription factor, EWS-WT1, which consists of the transcriptional activation domain of the Ewing's sarcoma (EWS) protein and the DNA binding domain of the Wilms' tumor 1 (WT1) protein. One of the splice variants, EWS-WT1(-KTS) lacks three amino acid residues (Lys-Thr-Ser) in the DNA binding domain and transforms NIH3T3 cells. Therefore, it is likely that aberrant gene expression caused by EWS-WT1(-KTS) is involved in the malignant phenotype of DSRCT. Microarray analysis of 9600 human genes revealed that a gene encoding a tetraspanin-family protein, T-cell acute lymphoblastic leukemia-associated antigen 1 (TALLA-1), was induced in EWS-WT1(-KTS)-expressing cell clones. This induction was EWS-WT1(-KTS)-specific, and more importantly, TALLA-1 protein was expressed in the three independent cases of DSRCT. Tetraspanin-family genes encode transmembrane proteins that regulate various cell processes such as cell adhesion, migration and metastasis. Our findings provide a novel insight into the malignant phenotype of DSRCT, suggesting that TALLA-1 is a useful marker for diagnosis and a potential target for the therapy of DSRCT.

Carcinoma, Small Cell↗
PubMed2003

Control of oxalate formation from L-hydroxyproline in liver mitochondria.

Serine:pyruvate/alanine:glyoxylate aminotransferase (SPT/AGT) is largely located in mitochondria in carnivores, whereas it is entirely found within peroxisomes in herbivores and humans. In rat liver, SPT/AGT is found in both of these organelles, and only the mitochondrial enzyme is markedly induced by glucagon. Although SPT/AGT is a bifunctional enzyme involved in the metabolism of both L-serine and glyoxylate, its contribution to L-serine metabolism is independent of mitochondrial or peroxisomal localization (Xue HH et al., J Biol Chem 274: 16028-16033, 1999). Therefore, the species-specific and food habit-dependent organelle distribution might be required for proper metabolism of glyoxylate at the subcellular site of its formation. Glyoxylate formation from glycolate and that from L-hydroxyproline have been shown to occur in peroxisomes and mitochondria, respectively. The present study found that urinary excretion of oxalate was markedly increased when a large dose of L-hydroxyproline or glycolate was administered to rats. Oxalate formation from L-hydroxyproline but not that from glycolate was significantly reduced when mitochondrial SPT/AGT had been induced by glucagon. The hydroxyproline content of collagen is 10 to 13%, and collagen accounts for about 30% of total animal protein; therefore, these results suggest that an important role of mitochondrial SPT/AGT in carnivores is to convert L-hydroxyproline-derived glyoxylate into glycine in situ, preventing undesirable overflow into the production of oxalate.

Animals↗
PubMed2002

OASIS is a transcriptional activator of CREB/ATF family with a transmembrane domain.

Murine OASIS is a putative CREB/ATF family transcription factor that is induced in gliosis, but its molecular role has not been determined. We have isolated the human OASIS gene and investigated the potential of OASIS protein as a transcriptional activator. We found that OASIS can activate transcription through box-B elements but not through the somatostatin CRE. OASIS contains a putative C-terminal hydrophobic transmembrane domain, a typical structural feature for the transcription factors activated by regulated intramembrane proteolysis. Truncation of the OASIS transmembrane domain resulted in a significant increase in transcriptional activity and altered its subcellular localization from the endoplasmic reticulum to the nucleus. Western blot analysis of transfected cells identified OASIS polypeptides of 82 and 66 kDa. These results suggest that the transmembrane domain plays an important role in the regulation of transcriptional activation by OASIS.

Activating Transcription Factors↗
PubMed2002

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↗