• 생명과학회지
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• 제23권7호
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• pp.947-954
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• 2013

Wnt/${\beta}$-catenin 신호는 세포의 운명 결정, 증식, 분화 등을 조절하는 척추 동물 배아 발생과 성체의 항상성 유지에 필수적인 세포신호전달경로이다. 이러한 Wnt/${\beta}$-catenin의 비정상적인 조절에 의해 선천적 기형, 암, 대사질환 등을 비롯한 다양한 질병이 유발된다. 이를 바탕으로 최근 Wnt/${\beta}$-catenin 신호의 조절을 통한 암을 비롯한 질병의 치료를 위한 연구가 활발히 진행되고 있다. 따라서 Wnt/${\beta}$-catenin 신호를 조절하는 인자의 발굴 및 자세한 작용 기전에 대한 연구가 절실히 필요하다. 본 총설에서는 최근 새롭게 알려진 Wnt/${\beta}$-catenin 신호 조절 기작에 대해 설명하고, 현재까지 알려진 Wnt/${\beta}$조절하는 인산화 효소(kinase)의 종류와 작용 기전과 새로운 약물 타겟으로 전망을 알아 보고자 한다.

• 대한의생명과학회지
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• 제2권1호
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• pp.21-30
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• 1996

Mitogen-activated protein (MAP) kinase는 여러 세포증식 촉진인자들에 의하여 자신이 인산화됨으로써 활성화되어 다른 protein kinase를 인산화시키는 역할을 하는 세포내 신호전달의 중요한 효소이다. 본 연구에서는 P388 murine leukemia 세포 파쇄액에서 SP sephadex C-50, phenyl superose, Mono Q column을 통하여 MAP kinase를 분리한 결과, 44 kD와 66kD의 isoform을 확인할 수 있었다. 면역 T 세포의 $p56^{kk}$의 N-terminal로부터 유전자 재조합 방법을 통하여 glutathion-s-transferase(GST) fusion protein을 얻은 후 분리한 MAP kinase의 기질로 사용하여 본 결과, wild type과 mutant간에 인산화 정도의 차이를 확인할 수 있어 MAP kinase의 또 다른 기질로 이용할 수 있는 가능성을 제시하였다.

• Journal of Microbiology and Biotechnology
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• 제8권4호
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• pp.325-332
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• 1998

In vitro phosphorylation experiments with a cell extract of Streptomyces coelicolor A3(2) M130 in the presence of ${\gamma}-[^32P]$]ATP revealed the presence of multiple phosphorylated proteins, including the AfsR/AfsK kinases which control the biosynthesis of A-factor, actinorhodin, and undecylprodigiosin. Phosphorylation of AfsR by a cell extract as an AfsK source was significantly inhibited by Ser/Thr protein kinase inhibitors, staurosporine and K-252a, at concentrations giving 50% inhibition ($IC_50$) of $1{\mu}M\;and\;0.1{\mu}M$, respectively. Further in vitro experiments with the cell extracts showed that phosphorylation of multiple proteins was inhibited by various protein kinase inhibitors with different inhibitory profiles. Manganese and calcium ions in the reaction mixture also modulate phosphorylation of multiple proteins. Manganese at 10 mM greatly enhanced the phosphorylation and partially circumvented the inhibition caused by staurosporine and K-252a. A calcium-activated protein kinase(s) was little affected by these inhibitors. Herbimycin and radicicol, which are known as tyrosine kinase inhibitors, did not show any significant inhibition of AfsR phosphorylation. Consistent with the in vitro effect of the kinase inhibitors, they inhibited aerial mycelium formation and pigmented antibiotic production on solid media. On the contrary, when assayed in liquid culture, the amount of actinorhodin produced was increased by staurosporine and K-252a and greatly decreased by manganese. All of these data clearly show that the genus Streptomyces possesses several protein kinases of eukaryotic types which are involved in the regulatory network for morphogenesis and secondary metabolism.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 1999년도 학술발표회 진행표 및 논문초록
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• pp.63-63
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• 1999

Large conductance $Ca^{2＋}$-activated $K^{＋}$ channels (Maxi-K channel) have been implicated in many important physiological processes such as co-ordination of membrane excitability in neurons. Modulation of these channels are archived by the activity of various protein kinases. The most widely studied example of Maxi-K channel regulation by protein phosphorylation has been obtained using plasma membranes from the rat brain incorporated into lipid bilayers.(omitted)

• 생명과학회지
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• 제26권10호
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• pp.1182-1188
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• 2016

Membrane associated guanylate kinase inverted-3 (MAGI-3)는 세포-세포 연접의 형성을 유도하는 막단백질인 membrane associated guanylate kinases (MAGUKs)의 한 종류 단백질로 140 kDa 크기를 가진다. MAGI-3는 PTEN/MMAC와 함께 협력하여 AKT/PKB의 kinase 활성을 조절하거나 MAPKs 신호전달경로로 ERK 활성을 조절로 한다. Coxsackievirus B3 (CVB3)는 가장 일반적으로 감염된 심근 세포 사멸으로 인한 바이러스성 심근염을 일으키는 enterovirus에 속하는 인간 병원체이다. 이전 연구에서 protein kinase B (PKB, 또는 AKT)와 extracellular signal-regulated kinases 1/2 (ERK1/2)의 활성은 HeLa 세포에서 CVB3 복제를 위해 필수적임이 밝혀졌다. 본 연구에서 enterovirus 복제와 AKT 신호 활성조절에서 MAGI-3의 역할을 검증하였다. MAGI-3-Flag의 발현은 CVB3 감염 후에 AKT 신호 활성과 viral capsid protein VP1의 발현을 유도하였으며 이는 MAGI-3에 의한 enterovirus 증식 조절을 보여주었다. AKT 신호는 MAGI-3 발현에 의해 enterovirus 감염과 함께 유의하게 증가하고 이것은 감염 바이러스의 증식을 활발하게 유도함을 확인하였다. 이 결과는 MAGI-3의 발현은 AKT와 ERK의 활성이 증가하고, 더 나아가 바이러스 증식과 연관이 있다는 것을 입증한다. MAGI-3는 아마도 AKT 신호 조절을 통해 enterovirus 증식 조절에 중요한 역할을 할 것으로 생각된다.

• Childhood Kidney Diseases
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• 제21권1호
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• pp.1-7
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• 2017

Mitogen-activated protein kinases (MAPKs) play important roles in various cellular functions including proliferation, differentiation, and apoptosis. We showed that MAPKs are developmentally regulated in the rat kidney. p38 MAPK (p38) and extracellular signal-regulated kinase (ERK) were strongly expressed in the fetal kidney, whereas c-Jun N-terminal kinase (JNK) was detected predominantly in the adult kidney. The inhibition of p38 or ERK in organ culture resulted in reduced nephron formation with or without reduced kidney size. On the other hand, persistent fetal expression pattern of MAPKs, i.e., upregulation of p38 and ERK and downregulation of JNK, was observed in the cyst epithelium of human renal dysplasia, ovine fetal obstructive uropathy, and pcy mice, a model of polycystic kidney disease. Furthermore, activated p38 and ERK induced by cyclic stretch mediated proliferation and $TGF-{\beta}1$ expression in ureteric bud cells, probably leading to cyst formation and dysplastic changes. Inhibition of ERK slowed the disease progression in pcy mice. Finally, ERK and p38 were inactivated in the early embryonic kidney subjected to maternal nutrient restriction, characterized by reduced ureteric branching and nephron number. Thus, MAPKs mediate the development of normal and diseased kidney. Their modulation may result in novel therapeutic strategies against developmental abnormalities of the kidney.

• BMB Reports
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• 제42권3호
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• pp.142-147
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• 2009

Small-molecule inhibitors of protein kinases have contributed immensely to our understanding of biological signaling path-ways and have been exploited therapeutically for the treatment of cancers and other disease states. The pyridinyl imidazole compounds SB 203580 and SB 202190 were identified as ATP competitive antagonists of the p38 stress-activated protein kinases and have been widely used to elucidate p38-dependent cellular processes. Here, we identify SB 203580 and SB 202190 as potent inhibitors of stress-induced CREB phosphorylation on Serine 111 (Ser-111) in intact cells. Unexpectedly, we found that the inhibitory activity of SB 203580 and SB 202190 on CREB phosphorylation was independent of p38, but instead correlated with inhibition of casein kinase 1 (CK1) in vitro. The inhibition of CK1-mediated CREB phosphorylation by concentrations of pyridinyl imidazoles commonly employed to suppress p38, suggests that in some cases conclusions of p38-dependence derived solely from the use of these inhibitors may be invalid.

• Animal cells and systems
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• 제10권3호
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• pp.115-120
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• 2006

Parkinson's disease (PD) is a neurodegenerative disease caused by selective degeneration of dopaminergic neurons in the substantia nigra. Mutations in ${\alpha}$-synuclein have been causally linked to the pathogenesis of hereditary PD. In addition, it is a major component of Lewy body found in the brains of sporadic cases as well. In the present study, we examined whether overexpression of wild type or PD-related mutant ${\alpha}$-synuclein induces unfolded protein response (UPR) and triggers the known signaling pathway of the resulting endoplasmic reticulum (ER) stress in SH-SY5Y cells. Overexpression of wild type, A30P, and A53T ${\alpha}$-synuclein all induced XBP-1 mRNA splicing, one of the late stage UPR events. However, activation of ER membrane kinases and upregulation of ER or cytoplsmic chaperones were not detected when ${\alpha}$-synuclein was overexpressed. However, basal level of cytoplsmic calcium was elevated in ${\alpha}$-synuclein-expressing cells. Our observation suggests that overexpression of ${\alpha}$-synuclein induces UPR independent of the known ER membrane kinase-mediated signaling pathway and induces ER stress by disturbing calcium homeostasis.

• Biomolecules & Therapeutics
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• 제19권4호
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• pp.371-389
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• 2011

A new strategy for cancer therapy has emerged during the past decade based on molecular targets that are less likely to be essential in all cells in the body, therefore confer a wider therapeutic window than traditional cytotoxic drugs which mechanism of action is to inhibit essential cellular functions. Exceptional heterogeneity and adaptability of cancer impose significant challenges in oncology drug discovery, and the concept of complex tumor biology has led the framework of developing many anticancer therapeutics. Protein kinases are the most pursued targets in oncology drug discovery. To date, 12 small molecule kinase inhibitors have been approved by US Food and Drug Administration, and many more are in clinical development. With demonstrated clinical efficacy of bortezomib, ubiquitin proteasome and ubiquitin-like protein conjugation systems are also emerging as new therapeutic targets in cancer therapy. In this review, strategies of targeted cancer therapies with inhibitors of kinases and proteasome systems are discussed. Combinational cancer therapy to overcome drug resistance and to achieve greater treatment benefit through the additive or synergistic effects of each individual agent is also discussed. Finally, the opportunities in the future cancer therapy with molecularly targeted anticancer therapeutics are addressed.

• Journal of Applied Biological Chemistry
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• 제65권3호
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• pp.167-172
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• 2022

Pathophysiological reaction of platelets in the blood vessel is an indispensable part of thrombosis and cardiovascular disease, which is the most common cause of death in the world. In this study, we performed in vitro assays to evaluate antiplatelet activity of artemether in human platelets and attempted to identify the mechanism responsible for protein phosphorylation. Artemether is a derivative of artemisinin, known as an active ingredient of Artemisia annua, which has been reported to be effective in treating malaria, and is known to function through antioxidant and metabolic enzyme inhibition. However, the role of artemether in platelet activation and aggregation and the mechanism of action of artemether in collagen-induced human platelets are not known until now. In this study, the effect of artesunate on collagen-induced human platelet aggregation was confirmed and the mechanism of action of artemether was clarified. Artemether inhibited the phosphorylation of PI3K/Akt and Mitogen-activated protein kinases, which are phosphoproteins that are known to act in the signal transduction process when platelets are activated. In addition, artemether decreased TXA₂ production and decreased granule secretion in platelets such as ATP and serotonin release. As a result, artemether strongly inhibited platelet aggregation induced by collagen, a strong aggregation inducer secreted from vascular endothelial cells, with an IC₅₀ of 157.92 μM. These results suggest that artemether has value as an effective antithrombotic agent for inhibiting the activation and aggregation of human platelets through vascular injury.