• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.4
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• pp.366-371
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• 2017

Six experimental diets for juvenile sea cucumbers Apostichopus japonicus were evaluated and compared with current commercial diets. Sea cucumbers (50 per tank; initial mean weight $2.3{\pm}0.1g$) in three replicates of seven groups were fed one of six experimental diets (ED1, 20% wild-harvested Sargassum thunbergii powder; ED2, 20% commercial S. thunbergii powder; ED3, 20% Undaria pinnatifida and Ascophyllum nodosum powders; ED4, 40% U. pinnatifida and A. nodosum powders; ED5, 10% brewer's yeast; and ED6, 10% sea shell powder) or a commercial diet (CD) for 28 weeks. The survival rate in all groups was 85-94%, with no significant difference among the experimental groups. The mean body weight of the sea cucumbers was significantly different among the experimental groups 6 weeks after the feeding trial. The final mean weight of the sea cucumbers was highest in ED1, ED3, and ED4, followed by ED6, ED5, ED2, and CD, in decreasing order. The results of this study suggest that U. pinnatifida and A. nodosum powders could provide a substitute for the S. thunbergii powder commonly used in commercial sea cucumber diets. Thus, the EP4 diet formulation, which contains no S. thunbergii, could be used as a practical feed for juvenile sea cucumbers.

• Molecules and Cells
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• v.25 no.4
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• pp.566-571
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• 2008

Calcineurin (Cn) is a calcium/calmodulin-dependent serine/threonine protein phosphatase that has diverse functions in different cell types and organisms. We screened proteins interacting with the C. elegans CnA homolog, TAX-6, by the yeast two-hybrid system. CNP-3 (Calcineurin interacting protein-3) is a novel protein that physically interacts with the catalytic domain of TAX-6. It is strongly expressed in the nuclei of intestine, hypodermis, dorsal uterine regions and spermatheca. Expression begins around the 60-cell stage and proceeds during all larval stages and the adult. To elucidate the biological function of cnp-3 we isolated a cnp-3 deletion mutant. Since CNP-3 binds CnA, we looked at factors associated with calcineurin loss-of-function mutants, such as brood size, body size, serotonin- and levamisole-mediated egg-laying behavior. The cnp-3(jh145) single mutant had no gross defects compared to wild-type animal. However, the phenotypes of the double mutants, tax-6(p675);cnp-3(jh145) and cnb-1(jh103);cnp-3(jh145), were more severe in terms of brood size, body size and serotonin-mediated egg-laying defects than tax-6(p675) and cnb-1(jh103), respectively. These results suggest that dysfunction of cnp-3 enhances certain calcineurin loss-of-function phenotypes in C. elegans.

• Molecules and Cells
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• v.28 no.1
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• pp.57-65
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• 2009

CDC48 is a member of the AAA ATPase superfamily. Yeast CDC48 and its mammalian homolog p97 are implicated in diverse cellular processes, including mitosis, membrane fusion, and ubiquitin-dependent protein degradation. However, the cellular functions of plant CDC48 proteins are largely unknown. In the present study, we performed virus-induced gene silencing (VIGS) screening and found that silencing of a gene encoding a tobacco CDC48 homolog, NgCDC48, resulted in severe abnormalities in leaf and shoot development in tobacco. Furthermore, transgenic tobacco plants (35S:anti-NgCDC48), in which the NgCDC48 gene was suppressed using the antisense RNA method, exhibited severely aberrant development of both vegetative and reproductive organs, resulting in arrested shoot and leaf growth and sterile flowers. Approximately 57-83% of 35S:anti-NgCDC48 plants failed to develop mature organs and died at early stage of development. Scanning electron microscopy showed that both adaxial and abaxial epidermal pavement cells in antisense transgenic leaves were significantly smaller and more numerous than those in wild type leaves. These results indicate that NgCDC48 is critically involved in cell growth and development of tobacco plants. An in vivo targeting experiment revealed that NgCDC48 resides in the endoplasmic reticulum (ER) in tobacco protoplasts. We consider the tantalizing possibility that CDC48-mediated degradation of an as-yet unidentified protein(s) in the ER might be a critical step for cell growth and expansion in tobacco leaves.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2000.04a
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• pp.53-60
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• 2000

Strain BH5 was isolated from naturally fermented Kimchi and identified as a bacteriocin producer, which has bactericidal activity against Micrococcus flavus ATCC 10240. Strain BH5 was identified tentatively as Lactococcus lactis by the API test and some characteristics. Lactococcus lactis BH5 showed a broad spectrum of activity against most of the non-pathogenic and pathogenic microorganisms tested by the modified deferred method. The activity of lacticin BH5, named tentatively as the bacteriocin produced by Lactococcus lactis BH5, was detected at the mid-log growth phase, reached its maximum during the early stationary phase, and decreased after the late stationary phase. Lacticin BH5 also showed a relatively broad spectrum of activity against non-pathogenic and pathogenic microorganisms as tested by the spot-on-lawn method. Its antimicrobial activity on sensitive indicator cells was completely disappeared by protease XIV or ${\alpha}$-chymotrypsin. The inhibitory activities of lacticin BH5 were detected during treatments up to 100$^{\circ}C$ for 30 min. Lacticin BH5 was very stable over a pH range of 2.0 to 9.0 and was stable with all the organic solvents examined. The cell concentration and bacteriocin production in strain BH5 were maximum when grown at 30$^{\circ}C$ in a modified MRS medium supplemented with 0.5% tryptone, 1.0% yeast extract, and 0.5% beef extract as nitrogen sources. It demonstrated a typical bactericidal mode of inhibition against Micrococcus flavus ATCC 10240. Lacticin BH5 was purified through ammonium sulfate precipitation, ethanol precipitation, and CM-Sepharose column chromatography. The apparent molecular mass of lacticin BH5 was estimated to be in the region of 3.7 kDa, by the direct detection of bactericidal activity after SDS-PAGE. Mutant strain NO141 which was isolated by nitrosoguanidine mutagenesis produced about 4 fold more bacteriocin than the wild type.

• Journal of Life Science
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• v.17 no.1 s.81
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• pp.39-44
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• 2007

The Rqh1 gene is essential for vegetative growth in fission Yeast. The rqh1 mutant showed that sensitivity of DNA damaging agent, a wild range of phenotype including abnormal gene expression and cell elongation. This result showed that the rqhl-overexpression cell was sensitivity to DNA damaging agent like rqhl mutant. When Rqh1 have an over-expression by $nmt1^+$ promoter of pREP vector, rqh1 mutant DNA damaging agent sensitivity could be compensated. We isolated two strong mutant containing complementation gene, rqh156 and rqh172, respectively. This result observed that the DNA damaging agent sensitivity of rqhl mutant was complemented by the expression of rqh156 and rqh172. They induced mRNA expression in a dose-dependent manner HU, MMS and UV. The HU sensitivity of the rqhl was complemented by the expression of rqh156 and rqh172. The mRNA expression of rqh156 decreased on HU dose dependent but the mRNA expression of rqh172 did not decrease on HU dose dependent. The MMS and W sensitivity of the rqhl was complemented by the expression of rqh156 and rqh172. These results indicate that the isolated rqhl gene may play an important role in DNA metabolism.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.4
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• pp.387-397
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• 2016

Neurofibrillary tangles (NFTs) of microtubule-associated protein tau are a pathological hallmark of Alzheimer's disease (AD). Endoplasmic reticulum (ER) stress has been known to be involved in the pathogenesis of AD. However, the exact role of ER stress in tau pathology has not yet been clearly elucidated. In present study, the possible relationship between tau pathology and ER stress was examined in terms of sorcin, which is a calcium binding protein and plays an important role in calcium homeostasis. Our previous yeast two hybrid study showed that sorcin is a novel tau interacting protein. Caspase-3-cleaved tau (T4C3) showed significantly increased tau-sorcin interaction compared to wild type tau (T4). Thapsigargin-induced ER stress and co-expression of constitutively active $GSK3{\beta}$ ($GSK3{\beta}-S9A$) also exhibited significantly increased tau-sorcin interactions. T4C3-expressing cells showed potentiated thapsigargin -induced apoptosis and disruption of intracellular calcium homeostasis compared to T4-expressing cells. Overexpression of sorcin significantly attenuated thapsigargin-induced apoptosis and disruption of calcium homeostasis. In contrary, siRNA-mediated knock-down of sorcin showed significantly increased thapsigargin-induced apoptosis and disruption of calcium homeostasis. These data strongly suggest that sequestration of sorcin by aberrant forms of tau compromises the function of sorcin, such as calcium homeostasis and cellular resistance by ER stress, which may consequently result in the contribution to the progression of AD.

• KSBB Journal
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• v.17 no.1
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• pp.38-43
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• 2002

Characteristics of cell growth and heavymetal adsorption by recombinant Saccharomyus cerevisiae strains harboring multiple copies of the CUP1 gene encoding metallothione (MT) protein were studied in batch cultures. Recombinant S. cerevisiae strains harboring multiple copies of the CUP1 gene were superior to the host and wild-type yeast strains in terms of cell growth and heavy metal removal, indicating that the copy number of the CUP1 gene for MT expression played an important role in the adsorption of heavy metals. It was suggested that the CUP1 promoter for the MT expression is induced by manganese and zinc as well as copper An optimum copper concentration for MT expression and concomitant adsorption of heavy metals by recombinant S. cerevisiae was found to be 0.31 mM. A nonionic surfactant Triton X-100 enhanced cell growth by 17.7% and removal of zinc by 6.1% compared with the control case.

• Journal of Microbiology
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• v.45 no.3
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• pp.227-233
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• 2007

In budding yeast, septin plays as a scaffold to recruits protein components and regulates crucial cellular events including bud site selection, bud morphogenesis, Cdc28 activation pathway, and cytokinesis. Phosphorylation of Bni5 isolated as a suppressor for septin defect is essential to Swe1-dependent regulation of bud morphogenesis and mitotic entry. The mechanism by which Bni5 regulates normal septin function is not completely understood. Here, we provide evidence that Bni5 phosphorylation is important for interaction with septin component Cdc11 and for timely delocalization from septin filament at late mitosis. Phosphorylation-deficient bni5-4A was synthetically lethal with $hof1{\Delta}$. bni5-4A cells had defective structure of septin ring and connected cell morphology, indicative of defects in cytokinesis. Two-hybrid analysis revealed that bni5-4A has a defect in direct interaction with Cdc11 and Cdc12. GFP-tagged bni5-4A was normally localized at mother-bud neck of budded cells before middle of mitosis. In contrast, at large-budded telophase cells, bni5-4A-GFP was defective in localization and disappeared from the neck approximately 2 min earlier than that of wild type, as evidenced by time-lapse analysis. Therefore, earlier delocalization of bni5-4A from septin filament is consistent with phosphorylation-dependent interaction with the septin component. These results suggest that timely de localization of Bni5 by phosphorylation is important for septin function and regulation of cytokinesis.

• Journal of Microbiology
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• v.37 no.4
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• pp.248-255
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• 1999

We have analyzed the MRE3/REC114 gene of Saccharomyces cerevisiae, previously detected in isolation of mutants defective in meiotic recombination. We cloned the MRE3/REC114 gene by complementation of the meiotic recombination defect and it has been mapped to chormosome XIII. The DNA sequence analysis revealed that the MRE3 gene is identical to the REC114 gene. The upstream region of the MRE3/REC114 gene contains a T_4C site, a URS (upstream repression sequence) and a TR (T-rich) box-like sequence, which reside upstream of many meiotic genes. Coincidentally, northern blot analysis indicated that the three sizes of MRE3/REC114 transcripts, 3.4, 1.4 and 1.2 kb, are induced in meiosis. A less abundant transcript of 1.4 kb is detected in both mitotic and meiotic cells, suggesting that it is needed in mitosis as well as meiosis. To examine the role of the MRE3/REC114 gene, we constructed mre3 disruption mutants. Strains carrying an insertion or null deletion of the MRE3/REC114 gene showed slow growth in nutrient medium and the doubling time of these cells increased approximately by 2-fond compared to the wild-type strain. Moreover, the deletion mutant (${\delta}$mre3) displayed no meiotically induced recombination and no viable spores. The mre3/rec114 spore lethality can be suppressed by spo13, a mutation that causes cells to bypass reductional division. The double-stranded breaks (DSBs) which are involved in initiation of meiotic recombination were not detected in the analysis of meiotic chromosomal DNA from the mre3/rec114 disruptant. From these results we suggest that the MRE3/REC114 gene product is essential in normal growth and in early meiotic stages involved in meiotic recombination.

• Mycobiology
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• v.47 no.3
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• pp.301-307
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• 2019

The $11{\alpha}$-hydroxylation of $16{\alpha}$, 17-epoxyprogesterone (EP) catalyzed by Rhizopus nigricans is crucial for the steroid industry. However, lower conversion rate of the biohydroxylation restricts its potential industrial application. The $11{\alpha}$-steroid hydroxylase CYP509C12 from R. oryzae were reported to play a crucial role in the $11{\alpha}$-hydroxylation in recombinant fission yeast. In the present study, the CYP509C12 of R. oryzae (RoCYP) was introduced into R. nigricans using the liposome-mediated mycelial transformation. Heterologous expression of RoCYP resulted in increased fungal growth and improved intracellular reactive oxygen species content in R. nigricans. The $H_2O_2$ levels in RoCYP transformants were approximately 2-folder that of the R. nigricans wild type (RnWT) strain, with the superoxide dismutase activities increased approximately 45% and catalase activities decreased approximately 68%. Furthermore, the $11{\alpha}$-hydroxylation rates of EP in RoCYP transformants (C4, C6 and C9) were 39.7%, 38.3% and 38.7%, which were 12.1%, 8.2% and 9.4% higher than the rate of the RnWT strain, respectively. This paper investigated the effect of heterologous expression of RoCYP in R. nigricans, providing an effective genetic method to construct the engineered strains for steroid industry.