• BMB Reports
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• 제51권6호
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• pp.261-262
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• 2018

Aurora B is an important kinase involved in dynamic cellular events in mitosis. Aurora B activity is controlled by several post-translational modifications (PTMs). Among them, E3 ubiquitin ligase-mediated ubiquitination plays crucial roles in controlling the relocation and degradation of Aurora B. Aurora B, ubiquitinated by different E3 ligases, moves to the exact site for its mitotic function during metaphase-anaphase transition and is then degraded for cell cycle progression at the end of mitosis. However, how the stability of Aurora B is maintained until its degradation has been poorly understood. Recently, we have found that USP35 acts as a deubiquitinating enzyme (DUB) for Aurora B and affects its stability during cell division, thus being involved in the regulation of mitosis. In this review, we discuss the USP35-mediated deubiquitination of Aurora B and the regulation of mitotic progression by USP35.

• 한국미생물·생명공학회지
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• 제50권3호
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• pp.436-440
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• 2022

본 연구에서는 염색체가공기술을 이용하여 xylan으로부터 다양한 대사산물을 생산할 수 있는 유전자를 도입한 효모인 공염색체를 구축하였다. 효율적인 염색체가공기술인 PCS법을 이용하기 위해 염색체 splitting에 필요한 splitting fragment (DNA module)를 각각 제작하였고, xylan 대사에 관여하는 유전자군을 가진 YKY164 균주에 형질전환하였다. 두번의 염색체 splitting에 의해 1,124 kb의 효모 7번염색체는 887 kb-YAC, 45 kb-mini YAC와 198 kb-YAC로 가공되었으며, 총 18개의 염색체를 가진 YKY183 균주를 구축하였다. 염색체가공을 위한 splitting efficiency는 50-78%였으며, 45 kb-mini YAC 상에 있는 외래유전자의 발현 및 효소활성은 염색체가공 전과 비교하여 유의미한 변화 및 저하는 관찰되지 않았다. 또한 생산된 재조합효소에 의한 xylan의 분해산물을 확인하였으며, 160 generation 동안 미니 효모인 공염색체는 염색체의 결실없이 안정적인 mitotic stability를 유지하였다.

• Molecules and Cells
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• 제39권3호
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• pp.204-210
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• 2016

DNA damage responses are important for the maintenance of genome stability and the survival of organisms. Such responses are activated in the presence of DNA damage and lead to cell cycle arrest, apoptosis, and DNA repair. In Caenorhabditis elegans, double-strand breaks induced by DNA damaging agents have been detected indirectly by antibodies against DSB recognizing proteins. In this study we used a comet assay to detect DNA strand breaks and to measure the elimination of DNA strand breaks in mitotic germline nuclei of C. elegans. We found that C. elegans brc-1 mutants were more sensitive to ionizing radiation and camptothecin than the N2 wild-type strain and repaired DNA strand breaks less efficiently than N2. This study is the first demonstration of direct measurement of DNA strand breaks in mitotic germline nuclei of C. elegans. This newly developed assay can be applied to detect DNA strand breaks in different C. elegans mutants that are sensitive to DNA damaging agents.

• 한국자기공명학회논문지
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• 제19권2호
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• pp.88-94
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• 2015

Bub1 is one of the spindle checkpoint proteins and plays a role in recruitment of the related proteins to kinetochore. Here, we studied the structural characteristic of the evolutionarily conserved 160 amino acid region in the N-terminus (hBub1 CD1), using Circular Dichroism (CD) and NMR. Our CD results showed that hBub1 CD1 is a highly helical protein and its structure was affected by pH: as pH was elevated to basic pH, the helical propensity increased. This could be related to the surface charge of the hBub1 CD1. However, the structural change did not largely depend on the salt concentration, though the thermal stability a little increased. The previous NMR analysis revealed that the hBub1 CD1 adopts eight helices, which is consistent with the CD result. Our result would be helpful for evaluating the molecular mechanism of the hBub1 CD1 and protein-protein interactions.

• Journal of Microbiology and Biotechnology
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• 제9권5호
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• pp.668-671
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• 1999

The gene encoding Schwanniomyces occidentalis $\alpha-amylase$(AMY) was introduced into Saccharomyces cerevisiae var. diastaticus which secreted only glucoamylase, by using a linearized yeast integrating vector to develop stable strains with a capability of secreting $\alpha-amylase$and glucoamylase simultaneously. A dominant selectable marker, the geneticin(G418) resistance gene (Gt^r$), was cloned into a vector to screen wild-type diploid transformants harboring the AMY gene. The amylolytic activities of transformants were about 3-7 times higher than those of the recipient strains. When grown in nonselective media, the transformants with the linearized integrating vector containing the AMY gene exhibited almost all of the mitotic stability after 100 generations.

• Molecules and Cells
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• 제27권1호
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• pp.1-3
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• 2009

Mitotic spindle mediates the segregation of chromosomes in the cell cycle and the proper function of the spindle is crucial to the high fidelity of chromosome segregation and to the stability of the genome. Nucleation of microtubules (MTs) from centrosomes and chromatin represents two well-characterized pathways essential for the assembly of a dynamic spindle in mitosis. Recently, we identified a third MT nucleation pathway, in which existing MTs in the spindle act as a template to promote the nucleation and polymerization of MTs, thereby efficiently amplifying MTs in the spindle. We will review here our current understanding on the molecular mechanism, the physiological function and the cell-cycle regulation of MT amplification.

• 미생물학회지
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• 제32권4호
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• pp.271-279
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• 1994

${\alpha}$-Amylase와 glucoamylase를 동시에 안정하게 분비하여 전분을 일단계로 직접 에탄올로 발효시킬수 있는 효모 균주를 개발하기 위하여 glucoamylase를 분비하는 Saccharomyces diastaticus hybrid 균주에 쥐의 침샘 유래의 ${\alpha}$-amylase cDNA 유전자를 plasmid vector를 이용하여 도입하였다. 이 균주로부터 효소생산에 필요한 유전자를 잃어버림이 없이 안정하게 분비할 수 있도록 하기 위하여 $\alpha$-amylase 유전자를 효모의 염색체에 삽입시키기 위한 integrating plasmid vector인 YIpMS$\Delta$R(LEU2)를 제작하였다. 이 vector의 효모형질전환에 있어 원형(circular)상태와 제한 효소 XbaI으로 처리된 직선화된(linearized) 상태의 두가지 형태를 비교한 결과 형질전환 효율에서나 형질전환체내의 $\alpha$-amylase 유전자 보유정도가 모두 직선화된 형태의 경우가 원형상태의 경우보다 높았다. Linearized vecotr를 가진 효모 형질전환체에서의 유전자 발현 안정도는 세포분열을 거듭할수록 episomal vecotr에 의한 효모 형질전환체에서의 발현 안정도보다 우수하게 나타났다. 또한 이 linearized vector를 가진 형질전환체는 $\alpha$-amylase와 glucoamylase를 동시에 분비하여 glucoamylase만 분비하는 원균주보다 2배 이상의 전분분해력을 보였다.

• BMB Reports
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• 제56권11호
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• pp.612-617
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• 2023

Pleiotropic regulator 1 (PLRG1), a highly conserved element in the spliceosome, can form a NineTeen Complex (NTC) with Prp19, SPF27, and CDC5L. This complex plays crucial roles in both pre-mRNA splicing and DNA repair processes. Here, we provide evidence that PLRG1 has a multifaceted impact on cancer cell proliferation. Comparing its expression levels in cancer and normal cells, we observed that PLRG1 was upregulated in various tumor tissues and cell lines. Knockdown of PLRG1 resulted in tumor-specific cell death. Depletion of PLRG1 had notable effects, including mitotic arrest, microtubule instability, endoplasmic reticulum (ER) stress, and accumulation of autophagy, ultimately culminating in apoptosis. Our results also demonstrated that PLRG1 downregulation contributed to DNA damage in cancer cells, which we confirmed through experimental validation as DNA repair impairment. Interestingly, when PLRG1 was decreased in normal cells, it induced G1 arrest as a self-protective mechanism, distinguishing it from effects observed in cancer cells. These results highlight multifaceted impacts of PLRG1 in cancer and underscore its potential as a novel anti-cancer strategy by selectively targeting cancer cells.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.162.2-162.2
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• 2003

Microtubule-organizing center (MOTC) plays pivotal roles in cell division process. Integrity of the spindle pole body (SPB) in Saccharomyces cerevisiae is required for migration and separation of sister chromatids in mitotic phase. Role of an essential SPB component, Spcl05, is poorly understood. Here we show that throughout all stage of cell division cycle, GFP-tagged Spcl05p localizes at SPB and its protein stability is fluctuated with mitosis-specific modifications. To gain new insights into the function of Spc105, we generated and characterized novel temperature sensitive spc105 mutants. (omitted)

• Journal of Microbiology and Biotechnology
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• 제8권5호
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• pp.441-448
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• 1998

A cellobiose-utilizing recombinant yeast having $\beta$-glucosidase activity was developed for ethanol production from a mixture of glucose and cellobiose. Using $\delta$-sequences of Tyl transposon of yeast as target sites for homologous recombination, a heterologous gene of $\beta$-glucosidase was integrated into the chromosome of Saccharomyces cerevisiae. The $\delta$-integrated recombinant yeast, Saccharomyces cerevisiae L2612 (Pb-BGL), showed perfect mitotic stability even in nonselective media and showed ca. 1.5 fold higher $\beta$-glucosidase activity than the recombinant yeast harboring the $2\mu$-based plasmid vector system. A mathematical model was developed to describe the $\beta$-glucosidase formation and ethanol production from the Saccharomyces cerevisiae L2612 ($p\delta-BGL$). The model newly described that the heterologous $\beta$-glucosidase production mediated by ADH1 promoter is regulated by glucose and repressed by ethanol.