Biomedical subjects

T Kusumi

Publications and source records attributed to T Kusumi.

At least 55 records · Page 3Linked to original sources

PubMed1995

Senescence-induced expression of a homologue of delta 9 desaturase in rose petals.

cDNAs for senescence-inducible genes were isolated by differential hybridization from a cDNA library derived from mRNAs from the petals of rose flowers. The amino acid sequence deduced from these cDNAs exhibited significant homology to those of delta 9 acyl-lipid desaturases of cyanobacteria and of delta 9 acyl-CoA desaturases of a yeast and mammals. There was no amino-terminal sequence indicative of a leader peptide for targeting to the chloroplasts or to mitochondria. Northern blot analysis indicated that the transcripts of the cDNAs were expressed specifically in petals at late developmental stages and during senescence. It is proposed that a delta 9 desaturase in the senescing petals play an important role in the degradation of saturated fatty acids of membrane lipids.

Aging↗

PubMed1995

Molecular cloning and characterization of Rosa hybrida dihydroflavonol 4-reductase gene.

A full length cDNA clone encoding rose dihydroflavonol 4-reductase (DFR) was isolated from a cDNA library derived from rose petals by screening with the cDNA of Petunia hybrida DFR. Sequence comparison of the rose DFR with reported DFR genes revealed that they are homologous to each other. The amount of DFR mRNA in rose petals was developmentally regulated and paralleled anthocyanin production in petals. Sepals, thorns, styles and stamens also contained anthocyanins and DFR mRNA. No DFR mRNA was observed in mature leaves and a small amount of the transcript was detected in young leaves. A petunia cultivar, whose colour was pale pink due to a deficiency in flavonoid 3'-hydroxylase and flavonoid 3',5'-hydroxylase, was transformed with a binary vector containing a rose DFR cDNA cloned behind a constitutive promoter. Petals and anthers of the resultant transgenic petunia plants were salmon pink and contained pelargonidin, an anthocyanidin rarely found in petunia.

Alcohol Oxidoreductases↗

PubMed1995

Complete sequence of an infectious full-length cDNA clone of citrus tatter leaf capillovirus: comparative sequence analysis of capillovirus genomes.

The complete nucleotide sequence of citrus tatter leaf capillovirus (CTLV lily strain) was determined. It is 6496 nucleotides long, excluding the 3'-terminal poly(A) tract, and contains two putative overlapping open reading frames (ORFs). ORF1 (positions 37-6354) encodes a potential polyprotein of molecular mass 242 kDa. ORF2 (positions 4788-5750) codes for a 36 kDa protein. The 242 kDa polypeptide contains several non-structural protein domains (i.e. methyltransferase, NTP-binding helicase, papain-like proteinase and polymerase) and, at its C terminus, the putative coat protein. The N-terminal region of the 36 kDa protein displays sequence similarity to the cell-to-cell movement proteins of the '30 K superfamily'. Such a genome structure is conserved between CTLV and apple stem grooving capillovirus. Capped transcripts from a plasmid containing the complete sequence of CTLV, with a T7 RNA promoter, successfully infected Chenopodium quinoa plants and caused symptoms characteristic of CTLV. Uncapped transcripts were noninfectious.

Amino Acid Sequence↗

PubMed1994

Nucleotide sequence of the coat protein coding region of tulip breaking virus.

cDNA of tulip breaking virus-tulip (TBV-tulip) RNA was synthesized and cloned in E. coli. One clone that contains a 4.5 kb insert was identified by restriction enzyme analysis, dot immunobinding assay (DIBA), and partial sequencing. Then 1479 nucleotides of the 3'-terminus of the clone were sequenced and revealed that the sequence contains one open reading frame (ORF), followed by an untranslated region of 255 nucleotides and a poly(A) tract. The deduced amino acid sequence was found to include the C terminus of the predicted RNA-dependent RNA polymerase and the coat protein. A glutamine-alanine dipeptide was identified as a putative NIa protease cleavage site at the N terminus of the coat protein.

Amino Acid Sequence↗

PubMed1994

Nucleotide sequence of the 3'-terminal region of citrus tatter leaf virus RNA.

The 3'-terminal sequence of citrus tatter leaf virus lily isolate (CTLV-L) was determined from cloned cDNA. The sequence contains two open reading frames (ORFs). ORF1 encodes a protein that contains consensus sequences associated with the RNA-dependent RNA polymerase. ORF2, which is in a different reading frame within ORF1, can encode a 36 kD protein, putatively identified as a movement protein. CTLV-L coat protein (CP) was found to be located in the C-terminal region of the polyprotein encoded by ORF1. Evolutionary relationships and classification of capilloviruses is discussed.

Amino Acid Sequence↗

PubMed1990

Identification of pentahydroxystearic acid-containing taurolipid (taurolipid C) isolated from Tetrahymena thermophila.

A pentahydroxystearic acid-containing taurolipid (taurolipid C) was found in cells of Tetrahymena thermophila. The lipid accounted for about 1.2% of the total taurolipids of the cells. The lipid was subjected to mild alkaline and methanolic hydrochloric acid hydrolyses, and the structures of the hydrolyses products were identified by mass and nuclear magnetic resonance spectrometries, as taurine, non-hydroxy fatty acid and 2,3,7,12,13-pentahydroxystearic acd, a novel fatty acid. The NMR spectra of the intact and acetylated lipid showed that the carboxyl group of the pentahydrxyostearic acid was combined with the amino group of taurine, and the hydroxy group at C-3 was esterified with non-hydroxy fatty acids. From these results, the pentahydroxystearic acid-containing taurolipid (taurolipid C) isolated from T. thermophila was identified as 2-(3-acyloxy-2,7,12,13-tetrahydroxyoctadecanoylamino)ethanesulf oni c acid.

Animals↗

PubMed1989

Dual inhibitory effect of bredinin.

Bredinin inhibition of cell growth was investigated in the mouse lymphoma cell line L5178Y. Bredinin caused the accumulation of IMP and the reduction of XMP. It was converted to the 5'-phosphate within the cells. Bredinin 5'-phosphate but not bredinin competitively inhibited both IMP dehydrogenase and GMP synthetase. Thus the inhibition of cell growth is probably due to bredinin 5'-phosphate, which inhibits the consecutive enzyme reactions IMP dehydrogenase and GMP synthetase. These inhibitions result in the accumulation of IMP and the reduction of XMP.

Animals↗

PubMed1989

Enhancing effects of immunoactive peptide FR48217 on immunological responses to vaccination by inactivated influenza virus.

The adjuvant effect of an immunoactive peptide, FR48217 (FR), was investigated in mice vaccinated with inactivated influenza virus with and without FR (designated as V + FR and V - FR, respectively). Mice were infected with influenza virus A/PR/8/34 28 days after vaccination. The survival rate indicated a strong adjuvant effect of FR on vaccination with inactivated influenza virus. No difference in interferon activity in the pulmonary lavage fluid was found between the V + FR and V - FR groups. The titres of virus-specific IgA and IgG antibodies in the serum increased after vaccination in both V + FR and V - FR groups and were significantly higher in the V + FR group than in the V - FR group. On days 2 and 4 after viral infection, the serum antibody titres decreased sharply and then increased again rapidly. The free IgA and IgG antibody levels in the pulmonary lavage fluid of vaccinated mice started to increase after day 4. It is proposed that one of the mechanisms by which FR has the adjuvant effect on vaccination is the increase of virus-specific IgA and IgG antibodies in the serum, which are diffused into the infection sites of the epithelial tissues in the respiratory tract to neutralize the virus at the early stages of viral infection.

Adjuvants, Immunologic↗

PubMed1988

Isolation and structural characterization of a diacyltaurolipid in cells of Tetrahymena mimbres.

A diacyltaurolipid was found in cells of Tetrahymena mimbres (formerly Tetrahymenas pyriformis NT-1). The lipid accounted for about 0.05% of the total lipids of the cells, and was composed of taurine (1 equiv.), 3,7,13-trihydroxystearic acid (1 equiv.) and non-hydroxy fatty acids (2 equiv.). By mild alkaline hydrolysis, non-hydroxy fatty acids (2 equiv.) and 2-(3,7,13-trihydroxyoctadecanoyl)aminoethanesulfonic acid were obtained. For determination of the positions of the ester bonds of the lipid, the free hydroxy group of the intact lipid was converted to a ketone, and the esterified hydroxy groups were acetylated after methanolic hydrochloric acid hydrolysis. By mass and nuclear magnetic resonance spectrometry, the structure of the derivative was identified as methyl 3,7-diacetoxy-13-oxooctadecanoate. From these results, the diacyltaurolipid isolated from T. mimbres was identified as 2-(3,7-diacyloxy-13-hydroxyoctadecanoyl)aminoethanesulfonic acid (7-acyltaurolipid A). This structure suggests that the diacyltaurolipid may be formed by acylation of taurolipid A.

Animals↗

PubMed1988

In vitro synthesis of IgE antibody by human tonsil mononuclear cells. Preliminary report.

Using anti-human IgE monoclonal antibody E235I63, an IgE antibody to mite extract response by peripheral blood lymphocytes (PBL) and tonsillar lymphoid cells from 3 atopic patients suffering nasal allergy and 2 normal individuals was detected by a sensitive radioimmunoassay of culture supernatants. Although the spontaneous IgE antibody response was characteristic of atopic PBL, PBL of normal controls did not produce anti-mite IgE antibody spontaneously. IgE antibody to mite extracts were detected in supernatants of all tonsillar cells cultured with mite antigen or PWM, but PBL from only atopic donors could produce IgE antibody in the same conditions.

Animals↗

PubMed1988

[Comprehension of synesthetic expressions: cross-modal modifications of sense adjectives].

This study examined (a) acceptability of phrases whose modifier adjective and head noun refer to different sense modalities, and (b) such cross-modal adjective properties by means of similarity judgment of these phrases. In Experiment 1, 58 subjects rated 60 sense adjectives as to their acceptability in modifying nine modality-denoting nouns (touch, taste, smell; color, sound; memory, mood, idea, personality). The phrases were rated highly acceptable when the adjectives denoting lower-modal qualities were combined with the nouns denoting higher-modal contents (e.g., soft sound, sweet mood, bright memory). In Experiment 2, two groups of 30 subjects judged the similarity of the highly acceptable phrases for each of the nine modality-denoting nouns. Multidimensional scaling of these data revealed two- and three-dimensional configurations of the adjectives for each modality-denoting noun. Multiple regression analysis indicated that two independently rated properties, pleasantness and intensity, provided a satisfactory interpretation of each configuration. Canonical correlation analysis indicated that most of the first- and second-order canonical correlations among the nine three-dimensional configurations were significant. These results suggest that there is a common dimension of sense adjectives across different modalities.

Adult↗

PubMed1987

Pathway of taurolipid B formation from exogenous taurolipid A by Tetrahymena thermophila.

When Tetrahymena thermophila was incubated with taurolipid A isolated from T. pyriformis NT-1, the exogenously added taurolipid A was deacylated rapidly, and taurolipid B content in the cells was increased. The deacylated taurolipid A (lysotaurolipid A) content reached a maximum early on during incubation, and then declined. Taurolipid B and lysotaurolipid B contents in the cells were increased continuously during the incubation. These observations suggest that lysotaurolipid A was an intermediate for taurolipid B formation. When cells were incubated with lysotaurolipid A, newly formed lysotaurolipid B and taurolipid B were observed. Furthermore, when cells were incubated with lysotaurolipid B, only taurolipid B was newly formed. In contrast, newly formed lysotaurolipid B was observed when cells were incubated with exogenous taurolipid B. From the results, we have postulated the biosynthetic pathway of taurolipid B from exogenous taurolipid A in cells of Thermophila.

Acylation↗

PubMed1981