• Molecules and Cells
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• 제38권8호
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• pp.705-714
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• 2015

We investigated the role of HDAC3 in anti-cancer drug-resistance. The expression of HDAC3 was decreased in cancer cell lines resistant to anti-cancer drugs such as celastrol and taxol. HDAC3 conferred sensitivity to these anti-cancer drugs. HDAC3 activity was necessary for conferring sensitivity to these anti-cancer drugs. The down-regulation of HDAC3 increased the expression of MDR1 and conferred resistance to anti-cancer drugs. The expression of tubulin ${\beta}3$ was increased in drug-resistant cancer cell lines. ChIP assays showed the binding of HDAC3 to the promoter sequences of tubulin ${\beta}3$ and HDAC6. HDAC6 showed an interaction with tubulin ${\beta}3$. HDAC3 had a negative regulatory role in the expression of tubulin ${\beta}3$ and HDAC6. The down-regulation of HDAC6 decreased the expression of MDR1 and tubulin ${\beta}3$, but did not affect HDAC3 expression. The down-regulation of HDAC6 conferred sensitivity to taxol. The down-regulation of tubulin ${\beta}3$ did not affect the expression of HDAC6 or MDR1. The down-regulation of tubulin ${\beta}3$ conferred sensitivity to anti-cancer drugs. Our results showed that tubulin ${\beta}3$ serves as a downstream target of HDAC3 and mediates resistance to microtubule-targeting drugs. Thus, the HDAC3-HDAC6-Tubulin ${\beta}$ axis can be employed for the development of anti-cancer drugs.

• Animal cells and systems
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• 제11권1호
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• pp.39-50
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• 2007

Tau plays a role in numerous neuronal processes, such as vesicle transport, microtubule-plasma membrane interaction and intracellular localization of proteins. SUMO (Small Ubiquitin-like Modifier) modification (SUMOylation) appears to regulate diverse cellular processes including nuclear transport, signal transduction, apoptosis, autophagy, cell cycle control, ubiquitin-dependent degradation, as well as gene transcription. We noticed that putative SUMOylation site is localized at $^{340}K$ of $Tau(^{339}VKSE^{342})$ with the consensus sequence information (${\Phi}KxE$ ; where ${\Phi}$ represents L, I, V or F and x is any amino acid). In this report, we demonstrated that $^{340}K$ of Tau is the SUMOylation site and that a point mutant of Tau S214E (an analog of the phospho $^{214}S$ Tau) promotes its SUMOylation at $^{340}K$ and its nuclear or nuclear vicinity localization, by co-immunoprecipitation and confocal microscopy analysis. Further, we demonstrate that the Tau S214E (neither Tau S214A nor Tau K340R) mutant increases its protein stability. However, the SUMOylation at $^{340}K$ of Tau did not influence cell survival, as determined by FACS analysis. Therefore, our results suggested that the phosphorylation of Tau on $^{214}S$ residue promotes its SUMOylation on $^{340}K$ residue and nuclear vicinity localization, and increases its stability, without influencing cell survival.

• BMB Reports
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• 제56권3호
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• pp.178-183
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• 2023

Huntington's disease (HD) is a neurodegenerative disorder, of which pathogenesis is caused by a polyglutamine expansion in the amino-terminus of huntingtin gene that resulted in the aggregation of mutant HTT proteins. HD is characterized by progressive motor dysfunction, cognitive impairment and neuropsychiatric disturbances. Histone deacetylase 6 (HDAC6), a microtubule-associated deacetylase, has been shown to induce transport- and release-defect phenotypes in HD models, whilst treatment with HDAC6 inhibitors ameliorates the phenotypic effects of HD by increasing the levels of α-tubulin acetylation, as well as decreasing the accumulation of mutant huntingtin (mHTT) aggregates, suggesting HDAC6 inhibitor as a HD therapeutics. In this study, we employed in vitro neural stem cell (NSC) model and in vivo YAC128 transgenic (TG) mouse model of HD to test the effect of a novel HDAC6 selective inhibitor, CKD-504, developed by Chong Kun Dang (CKD Pharmaceutical Corp., Korea). We found that treatment of CKD-504 increased tubulin acetylation, microtubule stabilization, axonal transport, and the decrease of mutant huntingtin protein in vitro. From in vivo study, we observed CKD-504 improved the pathology of Huntington's disease: alleviated behavioral deficits, increased axonal transport and number of neurons, restored synaptic function in corticostriatal (CS) circuit, reduced mHTT accumulation, inflammation and tau hyperphosphorylation in YAC128 TG mouse model. These novel results highlight CKD-504 as a potential therapeutic strategy in HD.

• 생명과학회지
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• 제33권11호
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• pp.950-955
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• 2023

세포 분열은 생명체의 생존과 발달에 필수적인 과정이며, 이 과정에서 복제된 염색체가 오류 없이 정확하게 두 개로 분리되는 것이 중요하다. 중심체(centrosome)는 미세소관 형성 센터(microtubule-organizing center, MTOC)를 구성하는 핵심 기관이며, MTOC는 세포 분열과정에서 방추체를 구성하는 미세소관을 형성한다. 또한 중심체는 세포에서의 신호 경로와 운동성에 관여한다. 정상적인 세포에서 중심체는 한개씩 존재하지만, S 기에서 2개로 복제되어 세포의 양쪽 끝으로 이동하며, MTOC로부터 생성된 방추사는 복제된 염색체와 결합하여 염색체를 양쪽 끝으로 이동시킨다. 이후 세포는 두 개로 나눠져 세포 분열을 종결한다. 하지만 중심체가 정상적인 숫자보다 많은 중심체 증폭(centrosome amplification) 현상은 암세포에서 흔하게 발생하며, 이것은 염색체 불안정성(chromosomal instability, CIN)을 일으키는 원인이 될 수 있다. 본 논문에서는 중심체 복제 과정에 대해 알아보고, 이 과정에서 PLK4의 역할에 대해 알아본다. 또한 중심체 증폭이 일으킬 수 있는 결과에 대해 알아보고, 중심체 증폭의 핵심 인산화효소인 PLK4를 저해하는 약물이 어떻게 특정 종류의 암세포를 치료하는 데 있어 기여할 수 있는지 고찰해 보고자 한다.

• 한국발생생물학회지:발생과생식
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• 제27권3호
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• pp.149-157
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• 2023

We investigated the involvement of autophagy with steroidogenesis in testicular Leydig cells. Human chorionic gonadotropin (hCG)-stimulated T production in Leydig cells was not remarkably altered in the presence of an autophagy inhibitor 3-methyladenine (3-MA). Although pretreatment with 3-MA demonstrated a tendency to decrease hCG-induced T production, the differences were significant only at a higher time point of 24 h following hCG. Microtubule associated protein light chain 3 (LC3)-II was detectable in the control cells in all the experiments. The hCG-induced increase in steroidogenic acute regulatory protein (StAR) and cytochrome P450 side chain cleave (P450scc) protein levels were not significantly altered by 3-MA. Leydig cells isolated from immature rat testes 12 h following hCG treatment showed relatively increased levels of LC3-II protein compared to the control group. Furthermore, LC3-II levels shown in these cells reached almost the identical to those from normal adult testes. However, LC3-II protein levels were almost comparable or even slightly lower than the controls at 48 h following hCG. Expression of StAR and P450scc was upregulated at both 12 and 48 h after hCG. We also used MA-10 cells, the mouse Leydig cell line, in this experiment. When dibutyryl cyclic-AMP was treated with MA-10 cells, P4 levels were significantly increased in the cell culture medium. However, P4 levels tended to decrease in the presence of 3-MA, but the difference was not statistically significant. This was consistent with the results of the rat Leydig cell experiments. Together, we believe that although autophagy participates in steroidogenesis and enhances steroidogenic efficacy of Leydig cells, it may not be a decisive cellular process for steroidogenesis, specifically in the mature Leydig cells.

• 생명과학회지
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• 제33권7호
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• pp.531-537
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• 2023

세포 내 수송 및 축삭 수송은 kinesin 및 cytoplasmic dynein과 같은 미세소관 의존성 모터단백질에 의해 운반된다. Kinesin은 미세소관을 따라 미세소관의 플러스 쪽 끝으로 이동하고, dynein은 미세소관의 마이너스 쪽 끝으로 이동한다. Kinesin-1은 kinesin superfamily protein (KIF)중에서 처음으로 확인된 kinesin으로, 카복실(C)-말단 영역과 cargo간 결합을 통해 세포내 소기관, 신경전달물질 수용체 및 mRNA-단백질 복합체를 포함한 다양한 cargo의 세포내 수송 기능을 수행한다. Kinesin-1은 다양한 cargo들을 수송하지만, kinsin-1과 cargo 사이를 매개하는 어댑터/스캐폴더 단백질은 아직 완전히 확인되지 않았다. KIF5A의 C-말단 영역과 상호 작용하는 어댑터 단백질을 규명하기 위해 효모 2-하이브리드 스크리닝을 하여, cyclin-dependent kinase 2-associated protein 1 (CDK2AP1)를 확인하였다. CDK2AP1은 KIF5A의 C-말단 영역에 결합하고 KIF3A, KIF5B, KIF5C 및 kinesin light chain 1 (KLC1)과는 결합하지 않았다. CDK2AP1의 C-말단 영역은 KIF5A와의 결합에 필수적이었다. HEK-293T 세포에 CDK2AP1 및 kinesin-1은 동시 발현하여 면역침강하면 CDK2AP1 및 kinesin-1은 같이 면역침강하였다. 그리고 CDK2AP1 및 kinesin-1은 세포내에서도 같은 위치에 발현하였다. 이러한 결과들은 KIF5A-CDK2AP1결합은 kinesin-1이 cargo를 운반할 때 kinesin-1과 cargo 사이를 연결하는 어댑터 단백질 역할을 시사한다.

• Animal cells and systems
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• 제1권2호
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• pp.317-321
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• 1997

Tau protein is one of the microtubule-associated proteins in the mammalian brain. In Alzheimer's disease, tau protein is immobilized in the somatodendritic compartment of certain nerve cells, where it forms a part of the paired helical filament (PHF). To understand the role of tau protein in the formation of PHF, a recombinant human tau protein expressed in Escherichia coli and five synthetic peptide fragments (peptide 1 to peptide 5), corresponding to the C-terminal region of tau protein, were prepared and their ability in self-assembly to form filamentous structures was examined. The recombinant human tau protein formed short rod-like structures in 0.1M MES buffer containing 1 mM $MgCI_2$, while a synthetic peptide fragment 1 containing 55 amino acid residues could assemble into a lot of long filamentous structures in water and particularly twisted helical structures in 0.1M MES buffer containing 1 mM $MgCI_2$. This suggests that the C-terminal region possesses a filament-forming ability and may be related to the formation of the helical structure by providing a powerful filament-forming driving force.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2004년도 춘계학술발표대회
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• pp.199-199
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• 2004

This study was conducted to investigate cytoskeleton alterations during vitrified (Open Pulled Straw method) porcine immature oocytes, to utilize Taxol/sup TM/ (polymerization of tubulin molecules) and Cytochalasin B (CB, depolymerization of actin filaments) during vitrification to stabilize microtubule and microfilaments (MT and MF), and to determine in vitro maturation, fertilization and development of cytoskeletal-stabilized and vitrified porcine immature oocytes. (omitted)

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2004년도 춘계학술발표대회
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• pp.258-258
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• 2004

Successful cryopreservation of mammalian oocytes would provide a source of materials for in vitro embryo production. This study was conducted to determine vitrification conditions for bovine immature oocytes using micro-drop method and, to examine maturation, fertilization and development of vitrified bovine immature oocytes. (omitted)

• Biotechnology and Bioprocess Engineering:BBE
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• 제6권4호
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• pp.252-263
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• 2001

Nematode infections compromise human health and reduce agricultural productivtiy. Experiments that exploit the powerful molecular genetics of the free-living nematode Caenorhabdl - elegans have contributed to our understanding of how the major classes of anthelmintic nema-tocides kill worms and how worms might evolve resistance to these drugs In C. elegans, as in parasites, benzimidixoles interfere with microtubule polyumerization the imidazothiazoles/tetra-hydropyrimidines activate nicotinic acetylcholine receptors, and the macrocyclic la ctones activate qlutamate-gate chloride chanels. Mutant alleles of genes that encode drug targes often confer resistance in C. elegans. Preliminary evidence suggests that alleles of homologous genes in parasites will, in many cases, also play a role in resistance. Thus information acquired from C. elegans can be usefully applied to understand the mechanisms of drug sensitivity and the genetics of resis-tance in parasites.