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K Shishido

Publications and source records attributed to K Shishido.

At least 19 recordsLinked to original sources
PubMed2003

Secretory production of Aspergillus oryzae xylanase XynF1, xynF1 cDNA product, in the basidiomycete Coprinus cinereus.

The signal peptide of Aspergillus oryzae endo-(1,4)-beta-xylanase XynF1 contains a C-terminal serine-arginine that directs efficient secretion of the enzyme into the culture medium. In the basidiomycete Coprinus cinereus, however, there is little secretion of XynF1 into the culture medium. Modification of the C-terminal sequence of the signal peptide to lysine-arginine resulted in efficient secretion of C. cinereus XynF1, suggesting the presence of a KEX2-like protease in this fungus.

Amino Acid Sequence↗
PubMed2001

Fragmentation reactions of optically active trisubstituted cyclopropylcarbinyl radicals.

Fragmentation reactions of optically active trisubstituted cyclopropylcarbinyl radicals and their application to the synthesis of natural products are described. Preparation of the optically pure substrates for radical fragmentation reactions was efficiently accomplished by lipase-mediated desymmetrization of sigma-symmetrical 3-substituted-1,2-cyclopropanedimethanols. In the presence of a radical stabilizing group, e.g., aryl, ester, or alpha,beta-unsaturated ester, the fragmentation occurs selectively to generate the radical on the alpha-carbon of the group and provide the optically pure alkene derivatives. These derivatives possess three chemically distinct functionalities, making them excellent chiral building blocks for the construction of biologically active molecules. The synthetic usefulness of the procedure developed here has been demonstrated by an application to the enantioselective synthesis of both enantiomers of the key intermediate, 4-(3,4-methylenedioxybenzyl)dihydrofuran-2(3H)-one (54), for the total synthesis of biologically active lignans.

Alkenes↗
PubMed2001

A novel tandem [2 + 2] cycloaddition-Dieckmann condensation with ynolate anions. Efficient synthesis of substituted cycloalkenones and naphthalenes via formal [n + 1] cycloaddition.

A novel tandem [2 + 2] cycloaddition-Dieckmann condensation via ynolate anions is described. Ynolate anions are useful for the formation of reactive beta-lactone enolates via a pathway not involving the enolization of the corresponding beta-lactones. The [2 + 2] cycloaddition of ynolate anions with delta- or gamma-keto esters, followed by Dieckmann condensation, gives bicyclic beta-lactones, which are easily decarboxylated to produce synthetically useful 2,3-disubstituted cyclopentenones and cyclohexenones in one pot. This tandem reaction was applied to a novel, one-pot synthesis of highly substituted naphthalenes.

Journal Article↗
PubMed2001

Cloning and sequence analysis of the basidiomycete Lentinus edodes ribonucleotide reductase small subunit cDNA and expression of a corresponding gene in L. edodes.

We have previously isolated the uck1 gene encoding UMP-CMP kinase from the basidiomycete Lentinus edodes (Kaneko et al., 1998). It was shown to be most actively transcribed in hymenophores of mature fruiting bodies of L. edodes. The reduction of NDPs produced by the nucleoside monophosphate kinase to dNDPs has been known to be catalyzed by ribonucleotide reductase (RNR) which consists of a heterodimer of large and small subunits. So we attempted to isolate the L. edodes cDNA(s) of RNR and study the expression in L. edodes of the corresponding gene(s), resulting in an isolation of the small subunit cDNA from a mature fruiting-body cDNA library of the fungus. This cDNA, named Le.rnr2c, was shown to encode a 418 amino acids (aa) protein, named Le.RNR2, of which the deduced aa sequence shows an overall identity of 71.9% to that of Schizosaccharomyces pombe RNR small subunit. The Le.rnr2 gene was found to be most actively transcribed in hymenophores of mature fruiting body of L. edodes. The in situ RNA-RNA hybridization analysis showed the presence of markedly large amount of the Le.rnr2 transcript in both hymenium and outer region of trama in the hymenophore. The same experiment was done for the uck1 gene, obtaining a similar result. The hymenium contains many basidia in which fusion of two nuclei, meiosis, replication, etc. essential for production of basidiospores occur. The outer region of trama is the region branching out into subhymenium. These imply that Le.rnr2 gene (and uck1 gene) play a role mainly in the nucleotide biosynthesis essential both for production of basidiospores and for divergence of trama cells into subhymenium cells in the hymenophore.

Amino Acid Sequence↗
PubMed2001

Cloning of a fatty acid synthase component FAS1 gene from Saccharomyces kluyveri and its functional complementation of S. cerevisiae fas1 mutant.

A gene encoding a fatty acid synthase component, FAS1, has been cloned from a genomic library of the polyunsaturated fatty acid (PUFA)-producing yeast Saccharomyces kluyveri. This gene (named Sk-FAS1) was found to contain an open reading frame of 6150 bp, coding for 2049 amino acids. The deduced Sk-FAS1 protein showed significant (75-59%) homology with FAS proteins from the other yeasts, including S. cerevisiae, Candida albicans and Yarrowia lipolytica. The substrate-binding sites of the acetyl transferase and malonyl/palmitoyl transferase domains, and the FMN- and NADPH-binding sites of the enoyl reductase domain, were all highly conserved. Expression of the Sk-FAS1 gene in S. cerevisiae complemented genetic disruption of the S. cerevisiae FAS1 gene (Sc-FAS1), suggesting the formation of a heterogeneous complex of Sk-FAS1 (beta) and Sc-FAS2 (alpha), which is able to function to synthesize fatty acids. Compared with the isogenic wild-type of S. cerevisiae, as well as S. kluyveri, the S. cerevisiae fas1 mutant carrying the Sk-FAS1 gene showed an increase in the relative amount of 16-carbon fatty acids and a decrease in 18-carbon fatty acids.

Amino Acid Sequence↗
PubMed2001

Glycine reduces novelty- and methamphetamine-induced locomotor activity in neonatal ventral hippocampal damaged rats.

The use of neonatal ventral hippocampal nVH lesioned rats is well established in animal models of schizophrenia. Moreover, the dysfunction of N-methyl-D-aspartate (NMDA) neurotransmission may play a crucial role in the pathophysiology of schizophrenia. To examine the effect of glycine (GLY) in this animal model, we compared the effects of GLY (0.8 and 1.6 g/kg, IP) on locomotor activity induced by a novel environment (NOVEL) and methamphetamine (MAP, 1.5 mg/kg, IP) in lesioned and sham-operated rats. Compared with sham rats, GLY significantly reduced NOVEL- and MAP-induced locomotor activity in lesioned rats (p <.001 and p <.05, respectively). It is suggested that GLY attenuated nVH-induced hyperactivity, and that this effect was evident both in the presence and absence of MAP. The nVH lesions may result in a form of hyperactivity that differs from normal locomotion in the degree to which it is highly sensitive to regulation by GLY.

Animals↗
PubMed2000

Decreased zinc ion accumulation by the basidiomycete Lentinus edodes over-expressing L. edodes PriA gene.

The information that the deduced expression product of Lentinus edodes priA gene consists of N-terminal hydrophobic sequence, putative zinc-binding motifs and C-terminal membrane-binding-promoting unique sequence led us to analyze its function in L. edodes. Here L. edodes monokaryotic cells over-expressing priA gene were found to exhibit a remarkably decreased accumulation of zinc ion, indicating the involvement of the priA gene in regulation of the intracellular zinc concentration.

Base Sequence↗
PubMed2000

Neurotoxic effect of high dose methamphetamine administration on the hippocampal formation of adult mice: morphometric study using image analyzer.

The volume of the hippocampal formation was measured after repeated methamphetamine (MAP) administration. MAP (30 mg/kg, i.p.) or an equivalent volume of saline (SAL) was administered once daily for 5 days to adult male BALB/c mice. The animals were perfused 7 days after the last injection, and brain sections were stained with cresyl violet and studied with a computer-assisted image analyzer. The volume of the molecular layer at the ventral position of the dentate gyrus of MAP-treated animals was significantly decreased (77% of control, p < 0.001). In contrast, the volumes of the molecular layers at the dorsal and midseptal positions of the dentate gyrus did not change after MAP administration. Similarly, repeated MAP treatment did not affect the volumes of the granular layer and hilus at the dorsal, midseptal or ventral positions of the dentate gyrus. The present results are the first to document a persistent neurotoxic effect of high dose MAP administration on the hippocampal volume of adult mice.

Animals↗
PubMed2000

Effects of phencyclidine on behavior and extracellular levels of dopamine and its metabolites in neonatal ventral hippocampal damaged rats.

RATIONALE: The use of neonatal hippocampal lesioned rats is well established in animal models of schizophrenia. Moreover, the dysfunction of N-methyl-D-aspartate (NMDA) neurotransmission may play a crucial role in the pathophysiology of schizophrenia. OBJECTIVE: To examine the role of NMDA neurotransmission in the neonatal ventral hippocampal damaged rat. METHODS: In initial experiments, we compared the effects of mild environmental stress (HAB) and the injection of saline and methamphetamine (MAP, 1.5 mg/kg, IP) in lesioned and sham-operated rats. We also examined the effects of a single injection of phencyclidine (PCP, 10 mg/kg, IP) on locomotor activity and extracellular levels of dopamine (DA) and its metabolites in the nucleus accumbens (NAc) of lesioned and sham-operated rats using an in vivo brain microdialysis method. RESULTS: Compared with sham-operated controls, the lesioned rats showed increased locomotor activity at postnatal day 56 (PD56) but not at PD35 after HAB and MAP administration. Similarly, the lesioned rats showed increased locomotor activity at PD56 but not at PD35 after PCP administration. Unexpectedly, the increase in DA levels was significantly greater in the sham-operated rats than in the lesioned rats. CONCLUSIONS: The results suggest that neonatal hippocampal lesioned rats are accompanied by the dysfunction of NMDA neurotransmission. They also suggest that hyperresponsiveness to PCP following neonatal hippocampal lesions does not depend on the extracellular DA concentration in the NAc.

Animals↗
PubMed2000

Structure and function of a pyrimidine/purine-biased sequence from the 5'-flanking region of the basidiomycete Lentinus edodes gene priA.

The priA gene of the basidiomycete Lentinus edodes possesses a pyrimidine (CT)-rich stretch (26 bp) that includes a short (6-bp) repeat, the elements of which form a mirror repeat at and near the transcriptional initiation sites. A DNA fragment that included this sequence was inserted into pBR322, and the resulting plasmids were introduced into Escherichia coli. Analysis of the susceptibility of these pBR322 derivatives to cleavage by S1 nuclease, following isolation from E. coli, indicated the formation of an open, S1-sensitive structure within and just downstream of the CT/AG-biased sequence. Replacement of two dTMP residues in one of the repeat elements by dGMP resulted in the elimination of the S1-cleavable open structure from the plasmids. To analyze the effect of the CT/AG-biased sequence from priA in the basidiomycete Coprinus cinereus, the integrating vectors pLC2 and pLC2mutCT were used; these contained the wild-type priA promoter and the mutant priA promoter with the aforementioned mutation in the mirror repeat, respectively. The Streptomyces-derived bialaphos resistance gene (bar) was fused downstream of the promoters, and the resulting plasmids, pLC2-bar and pLC2mutCT-bar, were introduced into C. cinereus. Transformants carrying pLC2mutCT-bar grew significantly more slowly on bialaphos-containing agar plates and contained a noticeably lower level of the bar transcript when compared with the transformants obtained with pLC2-bar. These results suggest that an unusual structure induced by the CT/AG-biased sequence is required for efficient gene expression from the priA promoter.

Base Sequence↗
PubMed2000

Basidiomycete fungal gene encoding a regulatory subunit A homologue of protein phosphatase 2A.

A gene, Le.paa, encoding a regulatory subunit A (PR65) homologue of protein phosphatase 2A was isolated from the basidiomycete mushroom Lentinus edodes. The deduced Le.paa gene product (Le.PR65) had the highest sequence similarity to the Schizosaccharomyces pombe PR65 protein (54.1% similarity). The Le.paa gene was shown to be transcribed more actively during the late stages of fruiting development of the fungus. Gill tissue in which basidiospores are formed contained abundant Le.paa transcript as compared with gill-depleted pileus and stipe.

Amino Acid Sequence↗
PubMed1999

Increased heavy metal sensitivity of Escherichia coli producing the expression product of priA gene derived from the basidiomycete Lentinus edodes.

We have previously isolated a developmentally regulated novel gene, priA, from the basidiomycete Lentinus edodes. The deduced PRIA protein contains the two set of motifs similar to a 'zinc finger' typified by transcription factor TFIIIA and the motif of a 'zinc cluster' observed in metallothioneins. It also contains a hydrophobic N-terminal sequence. Here Escherichia coli cells producing PRIA were found to show a remarkable sensitivity to zinc ion and other heavy metal ions such as nickel and cadmium. Deletion analysis of PRIA revealed that the zinc-binding motifs and the hydrophobic N-terminal sequence are responsible for conferring the heavy metal sensitivity on the host cells.

Cloning, Molecular↗
PubMed1999

Analysis of mfbA alleles of the eubasidiomycete Lentinus edodes.

A fruiting-body-specific mfbA cDNA derived from Lentinus edodes FMC2 has been shown to encode a high-molecular-weight protein, MFBA, containing the cell-adhesion-promoting Arg-Gly-Asp (RGD) sequence. Southern-blot analysis showed that all L. edodes strains tested have the mfbA gene (homologue). Nucleotide sequence analysis of the 1-kb mfbA fragments containing the RGD-coding sequence showed that each L. edodes strain has two types of mfbA homologues. It was found in FMC2 that two mfbA homologues are derived from different nuclei and these mfbA alleles are transcribed with similar frequencies in the fruiting bodies.

Alleles↗
PubMed1998

Cloning, sequence analysis and expression of the basidiomycete Lentinus edodes gene uck1, encoding UMP-CMP kinase, the homologue of Saccharomyces cerevisae URA6 gene.

Sequence analysis of the downstream region of the basidiomycete Lentinus edodes priB gene encoding a protein with a 'Zn(II)2Cys6 zinc cluster' DNA-binding motif (Endo, H., Kajiwara, S., Tunoka, O., Shishido, K., 1994. A novel cDNA, priBc, encoding a protein with a Zn(II)2Cys6 zinc cluster DNA-binding motif, derived from the basidiomycete Lentinus edodes. Gene 139, 117-121) suggested the presence of a Saccharomyces cerevisiae URA6 gene homologue encoding UMP kinase. We isolated a corresponding cDNA from a mature fruiting-body cDNA library of L. edodes. The nucleotide sequence of this was determined and compared with that of the genomic DNA, revealing that the URA6 gene homologue encodes 227 amino acids (aa) and is interrupted by four small introns. The deduced aa sequence showed an overall identity of 51.1% to that of the S. cerevisiae URA6 gene product. The URA6 homologue protein produced in Escherichia coli using the glutathione S-transferase gene fusion system was found to catalyze the phosphoryl transfer from ATP to UMP and CMP efficiently and also to AMP and dCMP with lower efficiencies. Thus, the URA6 gene homologue was designated uck1 and its product UMP-CMP kinase. Northern-blot analysis showed that the uck1 is actively transcribed in the gill tissue of mature fruiting bodies of L. edodes, implying that uck1 may play a role during the formation of basidiospores occurs in the gill tissue.

Amino Acid Sequence↗
PubMed1998

Molecular breeding of the basidiomycete Coprinus cinereus strains with high lignin-decolorization and -degradation activities using novel heterologous protein expression vectors.

Two chromosome-integrating vectors, pLC1 and pLC2, were used. The former is the pUC19-based vector carrying the Lentinus edodes ras gene promoter and priA gene terminator, and the latter is the pBR322-based vector carrying the promoter and terminator of the priA gene. The manganese (II) peroxidase (MnP) cDNA (mnpc) derived from Pleurotus ostreatus was fused between the promoter and terminator of pLC1 and pLC2, yielding the recombinant plasmids pLC1-mnp and pLC2-mnp. These plasmids were introduced into protoplasts of the Coprinus cinereus trp1 strain with the C. cinereus TRP1-containing plasmid pCc1001 by co-transformation. Two Trp+ transformants for each plasmid, showing clearly higher lignin-decolorization activities, were obtained through introduction of pLC1-mnp and pLC2-mnp. Southern-blot analysis revealed that the four transformants all possess the mnpc sequence on their chromosomes. One Trp+ MnP+ transformant (named TF2-7), which was derived from the introduction of pLC2-mnp and carried the highest number of copies (approx. 10) of mnpc, showed remarkably high lignin-decolorization and -degradation activities; at the time of cultivation when only 35%-40% of the lignin was decolored and degraded by the control Trp+ transformant obtained by the introduction of pCc1001 alone, almost all of the lignin was decolored and degraded by TF2-7.

Blotting, Southern↗