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T Shiina

Publications and source records attributed to T Shiina.

At least 73 records · Page 4Linked to original sources
PubMed1997

Nucleotide sequence analysis of the HLA class I region spanning the 237-kb segment around the HLA-B and -C genes.

To elucidate the detailed gene organization of the human leukocyte antigen (HLA) class I region on chromosome 6, seven contiguous cosmid genomic clones covering the 237-kb segment around the HLA-B and -C loci were subjected to DNA sequencing by the shotgun strategy to give a single contig of 236,822 bp from the MICA gene (58.2 kb centromeric of HLA-B) to 90.8 kb telomeric of HLA-C. This region was confirmed to contain four known genes, MICA, HLA-17, HLA-B, and HLA-C, from centromere to telomere. Further, a new member of the P5 multicopy genes was found to be about 1.3 kb upstream of the HLA-17 gene and designated P5.8. Five novel genes designated NOB1-5 were identified by RT-PCR and Northern blot hybridization. In addition, two pseudogenes, dihydrofolate reductase pseudogene (DHFRP) and ribosomal protein L3 homologous gene (RPL3-Hom), were also found in the vicinity of the HLA-B and -C genes, respectively. The two segments (about 40 kb) downstream of the HLA-B and HLA-C genes showed high sequence homology to each other, suggesting that segmental genome duplication including the major histocompatibility complex (MHC) class I gene must have occurred during the evolution of the MHC.

Blotting, Northern↗
PubMed1997

Mechanisms of enhanced production of PGI2 in cultured rat vascular smooth muscle cells enriched with eicosapentaenoic acid.

The present investigation was performed to clarify the effect of EPA on PGI2 production in vitro using cultured rat vascular smooth muscle cells (VSMC). To simulate in vivo conditions, a triacylglycerol (TG) emulsified form of EPA was used. An increase in EPA content was achieved without alteration of arachidonic acid concentration. These experiments clearly demonstrated that co-incubation of EPA-TG increased PGI2 production by cultured VSMC in a dose dependent fashion. Among polyunsaturated fatty acid TG examined (docosahexaenoic acid, linoleic acid, oleic acid and EPA), only EPA-TG was effective. Cyclooxygenase (COX) was activated, but neither phospholipase A2 nor PGI2 synthase activity was changed. EPA treatment did not alter the amount of COX-1 and COX-2 protein in VSMC. Addition of antioxidants, such as butylated hydroxytoluene or vitamin E, decreased MDA levels in the medium and cells and reversed the enhanced PGI2 production in EPA rich-VSMC. Therefore, the high polyunsaturation of EPA could generate low levels of lipid peroxides and thereby lead to activation of COX and an increased PGI2 production. Although EPA increased PGI2 production, only a negligible amount of PGI3 was produced by rat aortic tissues. Enhanced production of PGI2 might contribute to the anti-atherogenic effect of EPA.

Animals↗
PubMed1997

Characterization of dynamics of the psbD light-induced transcription in mature wheat chloroplasts.

Dynamical aspects of three chloroplast promoters responding to change in light condition were examined in mature chloroplasts of wheat (Triticum aestivum) by in vitro transcription. The wheat psbD/C operon has four distinct promoters, two of which named as D/C-3 and D/C-4 promoters dominantly function in mature chloroplasts to produce the mRNAs encoding D2/CP43 and CP43 alone, respectively. Activity of the D/C-3 promoter in mature chloroplasts was reduced to less than 30% by 24 h dark adaptation and recovered by re-illumination to the original level within 30 to 60 min. The activation of the D/C-3 promoter which requires de novo cytoplasmic protein synthesis was induced by low fluence of light (e.g. 16 microE m(-2) s(-1)), but the extent of activation increased with increasing light fluence. The accumulation of mRNAs from the D/C-3 promoter saturated at 2- to 3-fold higher level within 2 h when the dark-adapted seedlings were transferred to the light at 72 microE m(-2) s(-1), concomitant with the increase in rate of D2 synthesis, suggesting that synthesis of D2 in mature chloroplasts is controlled via the D/C-3 promoter activity in a light-dependent way. Activity of the D/C-4 promoter slightly increased in the dark and decreased in the light. Effect of light on the psbA promoter activity was not observed at all in mature chloroplasts. In vitro transcriptional analysis of the D/C-3 promoter with 5' deletion mutations revealed that at least two cis elements which are located within the sequences of -78 to -47 and -46 to -29 of the transcription initiation site, respectively, act as enhancing elements in the D/C-3 promoter. The light-switching element of the transcription, however, was suggested to be located in the core promoter sequence downstream of the -35 element.

Chloroplasts↗
PubMed1997

Role of PSII-L protein (psbL gene product) on the electron transfer in photosystem II complex. 1. Over-production of wild-type and mutant versions of PSII-L protein and reconstitution into the PSII core complex.

To establish a system for over-production of PSII-L protein which is a component of photosystem II (PSII) complex, a plasmid designated as pMAL-psbL was constructed and expressed in Escherichia coli JM109. A fusion protein of PSII-L and maltose-binding proteins (53 kDa on SDS-PAGE) was accumulated in E. coli cells to a level of 10% of the total protein upon isopropyl-beta-D-thiogalactopyranoside (IPTG) induction. The carboxyl-terminal part of 5.0 kDa was cleaved from the fusion protein and purified by an anion exchange column chromatography in the presence of detergents. This 5.0 kDa protein was identified as PSII-L by amino-terminal amino acid sequence analysis and the chromatographic behavior on an anion exchange gel. A few types of mutant PSII-L were also prepared by the essentially same procedure except for using plasmids which contain given mutations in psbL gene. Plastoquinone-9 (PQ-9) depleted PSII reaction center core complex consisting of D1, D2, CP47, cytochrome b-559 (cyt b-559), PSII-I and PSII-W was reconstituted with PQ-9 and digalactosyldiglyceride (DGDG) together with the wild-type or mutant PSII-L produced in E. coli or isolated PSII-L from spinach. Significant difference between the wild-type PSII-L proteins from E. coli and spinach was not recognized in the effectiveness to recover the photo-induced electron transfer activity in the resulting complexes. The analysis of stoichiometry of PQ-9 per reaction center in the PQ-9 reconstituted PS II revealed that two molecules of PQ-9 were reinserted into a reaction center independent of the presence or absence of PSII-L. These results suggest that PSII-L recovers the electron transfer activity in the reconstituted RC by a mechanism different from the stabilization of PQ-9 in the Q(A) site of PSII. Ubiquinone-10 (UQ-10), but not plastoquinone-2 (PQ-2), substituted PQ-9 for recovering the PSII-L supported electron transfer activity in the reconstituted PSII reaction center complexes. The results obtained with the mutant PSII-L proteins revealed that the carboxyl terminal part rather than amino terminal part of PSII-L is crucial for recovering the electron transfer activity in the reconstituted complexes.

Amino Acid Sequence↗
PubMed1997

Identification of promoter elements involved in the cytosolic Ca(2+)-mediated photoregulation of maize cab-m1 expression.

Changes in cytoplasmic Ca2+ levels are involved in the regulation of several plant genes. However, to our knowledge, no regions of genes or specific cis elements have been shown to be involved in the regulation of plant gene expression by cytosolic Ca2+ signaling. The maize (Zea mays) gene cab-m1, which encodes a light-harvesting chlorophyll a/b-binding apoprotein, is positively photoregulated in mesophyll cells (MC) but not in bundle-sheath cells (BSC). This gene is highly preferentially expressed in maize MC versus BSC. In situ transient expression assays have revealed that exposure of tissues to ethyleneglycol-bis(beta-aminoethyl ether)-N,N'-tetraacetic acid (EGTA), which chelates Ca2+, blocks the photostimulation of cab-m1 full promoter (-1026 to + 14) activity in MC of leaf segments of dark-grown maize seedlings. EGTA has no effect on expression in BSC. These results suggest that light-induced elevation of the cytosolic Ca2+ concentration in MC is required for the enhancement of cab-m1 expression in MC. Deletion of the sequence from -1026 to -360 completely abolished Ca2+ responsiveness of cab-m1 expression in MC. On the other hand, a 54-bp fragment in the 5' flanking region (-953 to -899 relative to the translation start site) conferred Ca2+ responsiveness on a -359 core promoter: reporter gene, suggesting that Ca2+ signaling is mediated via specific sequences in this short fragment. Furthermore, possible involvement of Ca(2+)-calmodulin in the signal transduction chain for regulating cab-m1 expression was suggested by the results of inhibitor experiments.

Base Sequence↗
PubMed1997

Triplet repeat polymorphism in the NOTCH4 gene with the human major histocompatibility complex in a healthy population and patients with a salivary gland tumor in Japan.

The NOTCH4 gene, the human counterpart of the mouse mammary tumor gene, int-3, has been recently localized near the boundary of the HLA class II and class III regions. This gene is one of candidates for development of salivary gland tumor. Microsatellite polymorphism of (CTG)n repeat in the signal peptide domain of NOTCH4 was analyzed in Japanese including the patients with salivary gland tumor. Four alleles consisting of 6, 9, 10 and 11 repetitions of CTG (Leu) were observed and found to be in linkage disequilibria with HLA class I and class II alleles. No significant association of this microsatellite polymorphism with the disease were observed in 26 samples of salivary gland tumor. In this neoplasia, neither large-scale deletion nor translocation was detected around the NOTCH4 gene using genomic Southern hybridization analysis by the NOTCH4 cDNA as a probe.

Alleles↗
PubMed1996

cDNA cloning of the human homologues of the mouse Ke4 and Ke6 genes at the centromeric end of the human MHC region.

cDNA clones corresponding to the HKE4 and HKE6 genes at the centromeric end of the HLA region on human chromosome 6p21.3 were isolated and characterized. The predicted amino acid sequences of HKE4 and HKE6 exhibited 81.5 and 85.6% identity to the mouse homologues, Ke4 and Ke6, respectively. HKE4 may encode a membrane protein with histidine-rich charge clusters. HKE6 possesses remarkable amino acid sequence conservation with several bacterial proteins with oxidoreductase function and also shows significant homology with the two unique functional domains containing the nucleotide cofactor binding site and the consensus motif characteristic of the members of the superfamily of short-chain alcohol dehydrogenases such as human and rat steroid and prostaglandin dehydrogenases.

Amino Acid Sequence↗
PubMed1996

Eicosapentaenoic acid suppressed the proliferation of vascular smooth muscle cells through modulation of various steps of growth signals.

Among fatty acids, only n-3 polyunsaturated fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) inhibited the proliferation of vascular smooth muscle cells. DHA was less effective than EPA. To clarify the anti-proliferative effect of n-3 polyunsaturated fatty acid, we have explored the effect of EPA on the signal transduction pathway of platelet derived growth factor (PDGF). EPA inhibited PDGF binding on its receptor and activation of protein kinase C. EPA also suppressed c-fos mRNA expression, one of immediate early genes, through partly inhibiting c-fos transcription. These data revealed that EPA could inhibit vascular smooth muscle cell proliferation through modulating various steps of the signal transduction by PDGF.

Animals↗
PubMed1996

Genetic polymorphisms in the keratin-like S gene within the human major histocompatibility complex and association analysis on the susceptibility to psoriasis vulgaris.

Psoriasis vulgaris is associated with the HLA-Cw6 and Cw7 antigens. However, it has not yet been clarified if the HLA-Cw6 and Cw7 genes themselves are the susceptible gene related to this disease or if it is some other non-HLA gene in a linkage disequilibrium with these HLA-C alleles. The S gene, recently identified in the HLA class I region 160 kb telomeric of HLA-C, encodes a keratin-like protein and is expressed specifically in the granular layer of the epidermis. Therefore, it is tempting to speculate that the S gene is one of the strong candidate genes responsible for the pathogenesis of psoriasis vulgaris. Direct sequencing of the first and second exon of the S gene after polymerase chain reaction (PCR) amplification has allowed the identification of two diallelic polymorphic sites in exon I and seven diallelic polymorphic sites in exon 2, three among which result in amino acid exchanges, a Ser-Phe substitution at amino acid position 186, a Gly-Val substitution at position 393 and a Ser-Leu substitution at position 394. No significant difference in the dimorphic distributions of the S gene was observed between the patients with psoriasis vulgaris and healthy controls, suggesting that the susceptible gene for psoriasis is not the S gene itself.

Disease Susceptibility↗
PubMed1995

Purification and characterization of RNA polymerase holoenzyme (E sigma B) from vegetative-phase mycelia of Streptomyces griseus.

RNA polymerase was purified from vegetative-phase mycelia of Streptomyces griseus by a series of ion-exchange chromatographies. By western blot analysis using antiserum against S. coelicolor HrdB, which is a principal sigma factor (sigma(hrdB)), the purified holoenzyme was found to contain sigmaB (=sigma(hrdB)) of S. griseus. Significant amounts of HrdB protein were, however, eluted from the DEAE column at lower concentrations of KCl than that required for for elution of the holoenzyme containing sigmaB, suggesting that sigmaB is dissociated from the core enzyme, or an excess amount of sigmaB exists in S.griseus cells. The holoenzyme containing sigmaB (EsigmaB) transcribed in vitro the dagA promoter of S. coelicolor, and the hardB and hsp70 promoters of S. griseus, suggesting that it is involved in transcription of the essential genes. EsigmaB may be a major form of RNA polymerase holoenzyme in the growing phase of S. griseus.

Bacterial Proteins↗
PubMed1995

[Evaluation of compression radiotherapy in pelvic treatment].

In pelvic irradiation, the volume of irradiated small intestine is one of the major factors responsible for both acute and late gastrointestinal complications. In this study, exclusion of the small intestine from the pelvic radiation field was attempted with lower abdominal wall compression and bladder distention in the prone position. The mobility of intrapelvic and several problems associated with this technique were investigated. In our results, the small intestine was effectively moved outside of the whole pelvic radiation field in all but two patients. Treatment interruption of 2 days was observed in only two patients. With the AP/PA opposing field method the abdominal skin dose near the compression pillow was revealed to be higher and the dose at the isocenter was inhomogeneous; thus, a three- or four-field technique is recommended if abdominal wall compression is used.

Adult↗
PubMed1995

Synthesis and NMR applications of isotopically labeled 2'-deoxynucleosides. Stereospecific deuteration of the C2' methylene in [ul-11 C/15N]deoxyadenosine.

Stereospecific deuteration of the C2' methylenes of 2'-deoxynucleosides together with 13C label has been found to open up various applications for structural studies of DNA oligomers in solution. Major problems in analyzing the structure and dynamics of larger DNA oligomers by NMR are associated with geminal proton pairs attached to the C2' and C5' of sugar moieties. We have employed, with a minor modification, existing synthetic routes to prepare stereospecific deuteration of the C2' methylene to prepare 13C/2H-doubly labeled nucleosides. For example, [ul-13C/15N] adenosine, which was prepared by microbial fermentation using [13C6]-glucose and [15N]-ammonium salt as precursors, was derived into (2'R)- and (2'S)-[ul-13C/15N;2'-2H1]-2'-deoxy-adenosines. Each of these multiply labeled nucleosides was then incorporated into a DNA dodecamer, 5'-d(CGCG AATTCGCG)-3', which was examined by various NMR techniques in order to evaluate the precision and accuracy of the NMR parameters obtained for the labeled moieties.

Base Sequence↗