• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.1
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• pp.46-54
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• 1997

Sporulation in the fission yeast Schizosaccharomyces pombe has been regarded as an important model of cellular development and differentiation. S. pombe cells proliferate by mitosis and binary fission on growth medium. Deprivation of nutrients especially nitrogen sources, causes the cessation of mitosis and initiates sexual reproduction by malting between two sexually compatible cell types. Meiosis is then followed in a diploid cell in the absence of nitrogen source. DNA fragment complemented with the mutations of sporulation gene was isolated from the S. pombe gene library constructed in the vector, pDB 248' and designated as pDB (spo 5)1. We futher analyzed six recombinant plasmids, pDB (spo 5)2, pDB(spo 5)3, pDB(spo 5)4, pDB(spo 5)5, pDB(spo 5)6, pDB(spo 5)7, and found each plasmids is able to rescue the spo 5-2, spo 5-3, spo 5-4, spo 5-5, spo 5-6, spo 5-7, mutations, respectively. Mapping of the integrated plasmid into the homologous site of the S. pombe chromosomes demonstrated that pDB (spo 5)1, and pDB (spo 5)R1 contained the spo 5 gene. Transcipts of spo 5 gene were analyzed by Northern hybridization. Two transcripts of 3.2 kb and 25 kb were detected with 5 kb Hind III fragment containing a part of the spo 5 gene as a probe. The small mRNA (2.5 kb) appeared only when a wild-type strain was cultured in the absence of nitrogen source in which condition the large mRNA (3.2 kb) was produced constitutively. Appearance of a 2.5 kb spo 5-mRNA depends upon the function of the mei1, mei2 and mei3 genes.

• Journal of Life Science
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• v.28 no.4
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• pp.496-507
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• 2018

Immunization has been performed for centuries and is generally accepted as a sustainable method of controlling bacteria, viruses, and mediated and infectious diseases. Despite many studies having been performed on animal subjects to demonstrate the importance of toxin immunity, the use of toxoid vaccines in humans and animals has been limited for a long time. Recently, the development of the toxoid antigen delivery system has been facilitated using novel nano-medicinal technology. The micro/nano-carrier has been used to improve vaccination coverage as well as reduce vaccine costs. A micro/nano-carrier is a micro/nano-sized material that delivers immune cargo, including recombinant or peptide toxoid antigens. These toxoid antigens are either encapsulated in the interior or displayed on the surface of micro/nano-carriers as a way to protect them from the cellular machinery. In particular, the combination of toxoid antigens and micro/nano-carriers can induce phagocytosis through the specific interactions between GCs and macrophages; thus, the toxoid antigens can be delivered easily into the macrophages. This paper reviews recent achievements of micro/nano-carriers in the field of vaccine delivery systems such as microbial ghost cells (GCs, Bacterial ghost cells and Yeast ghost cells), gene-manipulated outer membrane vesicles (OMVs) and biocompatible, polymer-based nanoparticles (NPs, NP-Carrier and NP-Cage). Finally, this review shows various aspects in terms of the hosts' immune responses.

• Korean Journal of Microbiology
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• v.52 no.1
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• pp.1-9
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• 2016

A unique Schizosaccharomyces pombe $TrxR^+$ gene encoding thioredoxin reductase (TrxR) was found to be positively regulated by stress-inducing agents through the stress-responsive transcription factor Pap1. In the present study, the protective roles of S. pombe TrxR were evaluated using the TrxR-overexpressing recombinant plasmid pHSM10. In the presence of hydrogen peroxide ($H_2O_2$) and superoxide anion-generating menadione (MD), S. pombe TrxR increased cellular growth and the total glutathione (GSH) level, while it reduced levels of intracellular reactive oxygen species (ROS). The nitric oxide (NO) levels of the TrxR-overexpressing cells, in the presence of $H_2O_2$ and MD, were maintained to be similar to those of the corresponding non-treated cells. Although S. pombe TrxR was able to scavenge NO generated by sodium nitroprusside (SNP), it had no significant modulating effects on cellular growth, ROS levels, or the total GSH level of SNP-exposed yeast cells, compared with the differences in those of the two non-treated cell cultures. TrxR increased the cellular growth and total GSH level, which were diminished by nitrogen starvation. It also scavenged ROS and NO produced during nitrogen starvation. Taken together, the S. pombe TrxR protects against oxidative, nitrosative, and nutritional stresses.

• Molecules and Cells
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• v.40 no.3
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• pp.230-242
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• 2017

In the Arabidopsis genome, approximately 80 MAP3Ks (mitogen-activated protein kinase kinase kinases) have been identified. However, only a few of them have been characterized, and the functions of most MAP3Ks are largely unknown. In this paper, we report the function of MAP3K16 and several other MAP3Ks, MAP3K14/15/17/18, whose expression is salt-inducible. We prepared MAP3K16 overexpression (OX) lines and analyzed their phenotypes. The result showed that the transgenic plants were ABA-insensitive during seed germination and cotyledon greening stage but their root growth was ABA-hypersensitive. The OX lines were more susceptible to water-deficit condition at later growth stage in soil. A MAP3K16 knockout (KO) line, on the other hand, exhibited opposite phenotypes. In similar transgenic analyses, we found that MAP3K14/15/17/18 OX and KO lines displayed similar phenotypes to those of MA3K16, suggesting the functional redundancy among them. MAP3K16 possesses in vitro kinase activity, and we carried out two-hybrid analyses to identify MAP3K16 substrates. Our results indicate that MAP3K16 interacts with MKK3 and the negative regulator of ABA response, ABR1, in yeast. Furthermore, MAP3K16 recombinant protein could phosphorylate MKK3 and ABR1, suggesting that they might be MAP3K16 substrates. Collectively, our results demonstrate that MAP3K16 and MAP3K14/15/17/18 are involved in ABA response, playing negative or positive roles depending on developmental stage and that MAP3K16 may function via MKK3 and ABR1.

• Korean Journal of Microbiology
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• v.41 no.4
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• pp.239-245
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• 2005

Transformation-Associated Recombination (TAR) cloning technique allows selective isolation of chromosomal regions and genes from complex genomes. The procedure requires knowledge of relatively small genomic sequences that reside adjacent to the chromosomal region of interest. This technique involves homologous recombination during yeast spheroplast transformation between genomic DNA and a TAR vector that has 5' and 3' gene targeting sequences. In this study, we examined the effect of non-homologous spacing sequence in target hooks on homologous recombination using a plasmid model system. The efficiency of homologous recombination between the modified his3-TRP1-his3 fragments and HlS3 gene on plasmid were analyzed by the characterization of $Ura^+$ transformants. The numbers of $Ura^+$ transformant showed same level when seven different modified his3-TRP1-his3 fragments were used. But the percentage of positive recombinants. $Trp^+His^-$, dramatically decreased when used the modified his3-TRP1-his3 fragments contained incorrect spacing of nonhomologous region. As a result, we suggest that incorrect spacing inhibits the homologous recombination between target hook and substrate DNA. Therefore, we should consider the correct spacing in target hook when the target hook are used for cloning of orthologue gene.

• Journal of Food Hygiene and Safety
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• v.21 no.2
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• pp.100-106
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• 2006

The use of underarm and body care cosmetics with oestrogenic chemical excipients (particularly the parabens) and the hypothesized association with breast cancer incidence, particularly in women. It is noted that the type of cosmetic product is irrelevant (e.g. antiperspirant/deodorant versus body lotion, moisturizers or sprays versus creams) and attention must focus on issues of actual exposure to chemicals through continued dermal application of body care products and the endocrine/hormonal activity and toxicity of the chemicals in the formulations. To evaluate the estrogenic activities of parabens such as ethylparaben, butylparaben, propylparaben, isobutylparaben and isopropylparaben, we used recombinant yeasts containing the human estrogen receptor [Saccharomyces cerevisiae ER+LYS 8127], human breast cancer MCF-7 cell lines and human estrogen receptor ${\alpha}\;and\;{\beta}$. In E-screen assays, isopropylparaben is the most estrogenic paraben, and in ER competition assay, isobutylparaben is the most estrogenic paraben. We evaluated isopropylparaben was most active in the recombinant yeast assay, followed by propylparaben, ethylparaben, isobutylparaben and butylparaben. Results from this study demonstrate that parabens are observed in human endocrine system. Therefore, we have shown that the parabens is induced the estrogenic activities similar to $17{\beta}$-estradiol and Bisphenol-A.

• The Korean Journal of Food And Nutrition
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• v.15 no.2
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• pp.112-118
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• 2002

Sporulation in the fission yeast Schizosaccharomyces pombe has been regarded as an important model of cellular development and differentiation. S. pombe cells proliferate by mitosis and binary fission on growth medium. Deprivation of nutrients especially nitrogen sources, causes the cessation of mitosis and initiates sexual reproduction by matting between two sexually compatible cell types. Meiosis is then followed in a diploid cell in the absence of nitrogen source. DNA fragment complemented with the mutations of sporulation gene was isolated from the S. pombe gene library constructed in the vector, pDB 248' and designated as pDB(spo5)1. We futher analyzed six recombinant plasmids, pDB(spo5)2, pDB(spo5)3, pDB(spo5)4, pDB(spo5)5, pDB (spo5)6, pDB(spo5)7 and found each of these plasmids is able to rescue the spo5-2, spo5-3, spo5-4, spo5-5, spo5-6, spo5-7 mutations, respectively. Mapping of the integrated plasmid into the homologous site of the S. pombe chromosomes demonstrated that pDB(spo5)1, and pDB(spu5)Rl contained the spo5 gene. Transcripts of spo5 gene were analyzed by Northern hybridization. Two transcripts of 3.2 kb and 2.5kb were detected with 5kb Hind Ⅲ fragment containing a part of the spo5 gene as a probe. The small mRNA(2.5kb) appeared only when a wild-type strain was cultured in the absence of nitrogen source in which condition the large mRNA (3.2kb) was produced constitutively. Appearance of a 2.5kb spo5-mRNA depends upon the function of the meil, mei2 and mei3 genes.