• BMB Reports
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• 제43권10호
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• pp.656-663
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• 2010

Amyloid precursor protein (APP), which is critically involved in the pathogenesis of Alzheimer's disease (AD), is cleaved by gamma/epsilon-secretase activity and results in the generation of different lengths of the APP Intracellular C-terminal Domain (AICD). In spite of its small size and short half-life, AICD has become the focus of studies on AD pathogenesis. Recently, it was demonstrated that AICD binds to different intracellular binding partners ('adaptor protein'), which regulate its stability and cellular localization. In terms of choice of adaptor protein, phosphorylation seems to play an important role. AICD and its various adaptor proteins are thought to take part in various cellular events, including regulation of gene transcription, apoptosis, calcium signaling, growth factor, and $NF-{\kappa}B$ pathway activation, as well as the production, trafficking, and processing of APP, and the modulation of cytoskeletal dynamics. This review discusses the possible roles of AICD in the pathogenesis of neurodegenerative diseases including AD.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2005년도 추계학술대회 및 한일 식물생명공학 심포지엄
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• pp.179-179
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• 2005

• Molecules and Cells
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• 제22권1호
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• pp.1-7
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• 2006

The NFAT family of transcription factors plays pivotal roles in the development and function of the immune system. Their activation process is tightly regulated by calcium-dependent phosphatase calcineurin and has been a target of the immunosuppressive drugs cyclosporin A and FK-506. Although the clinical use of these drugs has dramatically increased the success of organ transplantation, their therapeutic use is limited by severe side effects. Recent studies for the calcineurin/NFAT signaling pathway have identified a number of cellular proteins that inhibit calcineurin function. Specific peptide sequences that interfere with the interaction between calcineurin and NFAT have also been characterized. Moreover, diverse approaches to identify small organic molecules that modulate NFAT function have been performed. This review focuses on the recent advances in our understanding of the inhibitory modulation of NFAT function, which may open up the additional avenues for immunosuppressive therapy.

• BMB Reports
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• 제53권1호
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• pp.3-9
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• 2020

The mitochondrial genome encodes 13 proteins that are components of the oxidative phosphorylation system (OXPHOS), suggesting that precise regulation of these genes is crucial for maintaining OXPHOS functions, including ATP production, calcium buffering, cell signaling, ROS production, and apoptosis. Furthermore, heteroplasmy or mis-regulation of gene expression in mitochondria frequently is associated with human mitochondrial diseases. Thus, various approaches have been developed to investigate the roles of genes encoded by the mitochondrial genome. In this review, we will discuss a wide range of techniques available for investigating the mitochondrial genome, mitochondrial transcription, and mitochondrial translation, which provide a useful guide to understanding mitochondrial gene expression.

• 통합자연과학논문집
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• 제9권3호
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• pp.171-176
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• 2016

Rap1 is a key regulator of cell adhesion and migration. Although increasing evidence indicates that the Rap1 signaling pathway is involved in the process of bone remodeling, the mechanism by which Rap1 regulates osteoblastic differentiation and cell adhesion remains unknown. Here, we investigated the morphological characteristics and osteoblastic differentiation of cells expressing constitutively activated form of Rap1A (Rap1ACA) or Rap1 GTPase activating protein Rap1GAP and found that activated Rap1 induces osteoblastic differentiation and cell adhesion as well as cell spreading. When osteoblastic differentiation was induced, Rap1ACA cells showed considerably higher levels of calcium deposits than the wild-type and Rap1GAP-overexpressing cells did. Rap1ACA cells showed increased spreading and size, as well as strong cell adhesion and significantly decreased growth rates. F-actin staining using phalloidin revealed several thin thread-like filopodia around the protrusions in Rap1ACA cells, which possibly contribute to the increased cell adhesion.

• Genomics & Informatics
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• 제11권4호
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• pp.224-229
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• 2013

Receptor for advanced glycation endproducts (RAGE) is a multi-ligand receptor that is able to bind several different ligands, including advanced glycation endproducts, high-mobility group protein (B)1 (HMGB1), S-100 calcium-binding protein, amyloid-${\beta}$-protein, Mac-1, and phosphatidylserine. Its interaction is engaged in critical cellular processes, such as inflammation, proliferation, apoptosis, autophagy, and migration, and dysregulation of RAGE and its ligands leads to the development of numerous human diseases. In this review, we summarize the signaling pathways regulated by RAGE and its ligands identified up to date and demonstrate the effects of hyper-activation of RAGE signals on human diseases, focused mainly on renal disorders. Finally, we propose that RAGE and its ligands are the potential targets for the diagnosis, monitoring, and treatment of numerous renal diseases.

• 생명과학회지
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• 제32권2호
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• pp.108-118
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• 2022

뇌실하 영역은 뇌에서 신경줄기세포가 분포하는 곳으로 평생에 걸쳐 새로운 신경세포를 생성하는 곳이다. 많은 세포 안팎의 인자들이 신경줄기세포의 세포 증식과 신경세포로의 분화에 영향을 미친다. 최근 들어, L-type 칼슘 채널이 신경계의 발달을 조절하고 뇌실하 영역에 있는 신경줄기세포, 신경세포로 분화 중인 세포, 그리고 성숙한 신경세포에 분포한다고 밝혀졌다. L-type 칼슘 채널의 저해제인 nifedipine은 고혈압의 치료제로 오랜 기간 사용되어 왔다. 신경줄기세포에 nifedipine을 사용하여 L-type 칼슘 채널을 저해하는 연구는 많이 없는 상황이다. 이번 연구에서, 우리는 5일령 쥐의 뇌실하 영역에서 배양한 신경줄기세포에 nifedipine을 처리하여 신경세포로의 분화에 미치는 영향을 관찰하였다. Nifedipine은 Tuj1을 발현하는 신경세포의 수를 증가시킨 반면, Olig2를 발현하는 희소 돌기 아교 세포(oligodendrocytes)의 수에는 큰 영향을 미치지 않았다. Nifedipine은 S기를 표지하는 5-ethynyl-2'-deoxyuridine (EdU)가 들어간 세포의 수를 증가시켰고, 세포 분열시 나타나는 인산화된 히스톤 H3(PH3)를 발현하는 세포의 수를 증가시켰다. Nifedipine은 신경세포로의 분화를 촉진하는 Dlx2 유전자의 전사를 증가시켰고, 초기 신경세포에서 보이는 Mash1의 양도 증가시켰다. Nifedipine 외 또다른 L-type 칼슘 채널의 저해제인 verapamil을 처리하자, 신경세포로의 분화가 소폭 증가하였으나, 통계적 유의미성은 매우 낮았다. T-type 칼슘 채널의 저해제 유전자인 Cav3.1, Cav3.2, Cav3.3가 발현함을 관찰하여, T-type 칼슘 채널의 저해제인 pimozide를 신경줄기세포에 처리하였으나, 신경세포로의 분화에는 변화가 없었다. 이러한 결과를 통해 nifedipine이 신경줄기세포의 초기 분화를 증진함을 알 수 있으며, L-type 칼슘 채널이 신경세포로의 분화에 관여함을 알 수 있다.

• 생명과학회지
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• 제27권12호
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• pp.1393-1402
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• 2017

식물에서, 칼슘-의존적 단백질 카이네즈(CDPKs)는 $Ca^{2+}$ 신호전달에서 중요한 $Ca^{2+}$ 수용체이다. 벼(Oryza sativa L.)의 CDPKs인 3개의 OsCPKs는 생물정보에 대한 분석이 이루어졌으나, OsCPK11 유전자는 연구가 완전히 수행되지 않았다. 다양한 조직에서 OsCPK11 유전자가 전사수준에서 발현한다는 것은 알려져 있으나, 단백질 수준에서 발현과 생화학적인 특징은 잘 알려져 있지 않다. 이 연구는 OsCPK11의 몇 가지 생화학적 특징을 알아보기 위해 이루어졌다. 먼저 in vitro에서 E. coli를 이용하여 GST-OsCPK11를 발현시키고, 카이네즈 활성 측정과 칼슘-의존적 단백질 카이네즈로서 OsCPK11의 생화학적 분석도 수행하였다. OsCPK11은 스스로 자가인산화하며, $Ca^{2+}$의 존재 하에서 기질로서 histone III-s와 MBP로 인산기 전달 작용을 수행한다. 재조합 OsCPK11의 활성은 $Mg^{2+}$에 의해 영향을 받으며, pH 7.0-7.5에서 최적의 활성을 보인다. 또한 OsCPK11의 활성은 높은 수준의 $Ca^{2+}$가 존재하는 조건에서는 $Mg^{2+}$, $Mn^{2+}$, $Na^+$의 영향을 받지 않는다. 또한 OsCPK11의 자가인산화는 OsCPK11의 $Ca^{2+}$ 민감도를 감소시키는 것으로 밝혀졌다. 마지막으로, OsCPK11의 N-말단 다양화 지역으로 토끼 항체를 만들었고, immunoblot을 기초로 polyclonal antibody는 95.5 kD의 GST-OsCPK11를 인식하는 것으로 나타났다. 이 결과는 벼의 $Ca^{2+}$ 매개 신호전달에서 OsCPK11의 기능을 더 잘 이해하는데 도움을 줄 것이며, 심화 연구를 위해 다양한 OsCPKs의 단백질 정보를 결정하는 것이 필요할 것이다.

• The Korean Journal of Physiology and Pharmacology
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• 제9권2호
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• pp.103-108
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• 2005

To study the direct effect of somatostatin (SS) on calcium channel current ($I_{Ba}$) in guinea-pig gastric myocytes, $I_{Ba}$ was recorded by using whole-cell patch clamp technique in single smooth muscle cells. Nicardipine ($1{\mu}M$), a L-type $Ca^{2+}$ channel blocker, inhibited $I_{Ba}$ by $98{\pm}1.9$% (n=5), however $I_{Ba}$ was decreased in a reversible manner by application of SS. The peak $I_{Ba}$ at 0 mV were decreased to $95{\pm}1.5$, $92{\pm}1.9$, $82{\pm}4.0$, $66{\pm}5.8$, $10{\pm}2.9$% at $10^{-10}$, $10^{-9}$, $10^{-8}$, $10^{-7}$, $10^{-5}$ M of SS, respectively (n=3∼6; $mean{\pm}SEM$). The steady-state activation and inactivation curves of $I_{Ba}$ as a function of membrane potentials were well fitted by a Boltzmann equation. Voltage of half-activation ($V_{0.5}$) was $-12{\pm}0.5$ mV in control and $-11{\pm}1.9$ mV in SS treated groups (respectively, n=5). The same values of half-inactivation were $-35{\pm}1.4$ mV and $-35{\pm}1.9$ mV (respectively, n=5). There was no significant difference in activation and inactivation kinetics of $I_{Ba}$ by SS. Inhibitory effect of SS on $I_{Ba}$ was significantly reduced by either dialysis of intracellular solution with $GDP_{\beta}S$, a non-hydrolysable G protein inhibitor, or pretreatment with pertussis toxin (PTX). SS also decreased contraction of guinea-pig gastric antral smooth muscle. In conclusion, SS decreases voltage-dependent L-type calcium channel current ($VDCC_L$) via PTXsensitive signaling pathways in guinea-pig antral circular myocytes.

• Journal of Ginseng Research
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• 제39권3호
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• pp.279-285
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• 2015

Background: Korean Red Ginseng has been used as a traditional oriental medicine to treat illness and to promote health for several thousand years in Eastern Asia. It is widely accepted that ginseng saponins, ginsenosides, are the major active ingredients responsible for Korean Red Ginseng's therapeutic activity against many kinds of illness. Although the crude saponin fraction (CSF) displayed antiplatelet activity, the molecular mechanism of its action remains to be elucidated. Methods: The platelet aggregation was induced by collagen, the ligand of integrin ${\alpha}_{II}{\beta}_I$ and glycoprotein VI. The crude saponin's effects on granule secretion [e.g., calcium ion mobilization and adenosine triphosphate (ATP) release] were determined. The activation of mitogen-activated protein kinases (MAPKs), including extracellular signal-regulated protein kinase 1/2 (ERK1/2), c-Jun N-terminal kinases (JNKs), and p38 MAPK, and phosphoinositide 3-kinase (PI3K)/Akt was analyzed by immunoblotting. In addition, the activation of integrin ${\alpha}_{II}b{\beta}_{III}$ was examined by fluorocytometry. Results: CSF strongly inhibited collagen-induced platelet aggregation and ATP release in a concentration-dependent manner. It also markedly suppressed $[Ca^{2+}]_i$ mobilization in collagen-stimulated platelets. Immunoblotting assay revealed that CSF significantly suppressed ERK1/2, p38, JNK, PI3K, Akt, and mitogen-activated protein kinase kinase 1/2 phosphorylation. In addition, our fraction strongly inhibited the fibrinogen binding to integrin ${\alpha}_{IIb}{\beta}_3$. Conclusion: Our present data suggest that CSF may have a strong antiplatelet property and it can be considered as a candidate with therapeutic potential for the treatment of cardiovascular disorders involving abnormal platelet function.