• International Journal of Oral Biology
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• 제34권2호
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• pp.115-121
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• 2009

Bone morphogenetic protein (BMP) 2 is a potent osteogenic factor. Although both Smad1/5 and mitogenactivated protein kinases (MAPKs) are activated by BMP2, the hierarchical relationship between them is unclear. In this study, we examined if BMP2-stimulated MAPK activation is regulated by Smad1/5 or vice versa. When C2C12 cells were treated with BMP2, the activation of extracellular signal-regulated kinase (ERK), p38 MAPK and c-Jun-N-terminal kinase was evident within 5 min. The knockdown of both Smad1 and Smad5 by small interfering RNA did not affect the activation of these MAPKs. In addition, neither the overexpression of Smad1 nor Smad5 induced ERK activation. When ERK activation was induced by constitutively active MEK1 expression, the protein level and activation of Smad1 increased. Furthermore, the inhibition of constitutively active BMP receptor type IB-induced ERK activation significantly suppressed Smad1 activation. These results indicate that Smad1/5 activation is not necessary for BMP2-induced MAPK activation and also that ERK positively regulates Smad1 activation.

• BMB Reports
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• 제40권1호
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• pp.1-6
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• 2007

Apoptosis signal-regulating kinase 1 (ASK1) is a mitogenactivated protein kinase (MAPK) kinase kinase that activates JNK and p38 kinases. ASK1 is activated by various stresses, such as reactive oxygen species (ROS), endoplasmic reticulum (ER) stress, lipopolysaccharide (LPS) and calcium influx which are thought to be responsible for the pathogenesis or exacerbations of various human diseases. Recent studies revealed the involvement of ASK1 in ROS- or ER stressrelated diseases, suggesting that ASK1 may be a potential therapeutic target of various human diseases. In this review, we focus on the current findings for the relationship between pathogenesis and ASK1-MAPK pathways.

• BMB Reports
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• 제40권3호
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• pp.325-332
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• 2007

The mitogen-activated protein kinase (MAPK) cascade is one of the major and evolutionally conserved signaling pathways and plays pivotal role in the regulation of stress and developmental signals in plants. Here, a novel gene, termed Gossypium hirsutum MAPK (GhMAPK), was isolated from cotton. The full-length cDNA of GhMAPK encodes for a 372 amino acid protein that contains all 11 of the MAPK conserved subdomains and the phosphorylationactivation motif, TEY. Amino acid sequence alignment revealed that GhMAPK shared high identity with group-C MAPK in plants and showed 83~89% similarities with MAPKs from Arabidopsis, apricot, pea, petunia, and tobacco. Southern blot analysis indicated that the GhMAPK belonged to a multygene family in cotton. Two introns were found within the region of genomic sequence. Northern blot analysis revealed that the transcripts of GhMAPK accumulated markedly when the cotton seedlings were subjected to various abiotic stimuli such as wounding, cold (4$^{\circ}C$), or salinity stress; Furthermore, GhMAPK was upregulated by the exogenous signaling molecules, such as salicylic acid (SA) and hydrogen peroxide ($H_2O_2C$), as well as pathogen attacks. These results indicate that the GhMAPK, which has a high degree of identity with group-C plant MAPKs, may also play an important role in response to environmental stresses.

• Journal of Applied Biological Chemistry
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• 제66권
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• pp.122-127
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• 2023

심혈관 질환(CVD)은 전 세계적으로 주요 사망 원인으로써 갈수록 증가하는 추세이며, 혈관 손상이 발생하였을 때, 혈전이 과도하게 형성되는 것이 그 원인인 중 하나이다. 근래에 혈소판 억제를 통한 항혈전 물질에 대한 관심이 커지고 있으며 천연 생물활성 화합물을 사용함으로써 부작용을 줄이려는 노력이 이루어지고 있다. Flavonoid 중 하나로 알려진 hydroxygenkwanin(HGK)은 팥꽃나무(Daphne genkwa)에서 정제되는 물질로서 항균, 항염증 및 항암 효과가 있다고 알려져 있으며, 혈전증을 예방하는 조직 인자의 억제제 역할을 한다고 보고되었지만 항혈소판 효과와 그 작용기전에 대해서는 거의 알려지지 않았다. 본 연구를 통해 HGK가 collagen 유도의 사람 혈소판 응집에 미치는지 확인하였고, 그 작용 기전을 확인하였다. HGK은 혈소판 신호 전달 과정에서 PI3K/AKT 및 MAPK의 인산화를 억제하였고, ATP 및 serotonin 등의 혈소판 내 과립 분비를 감소하였다. . 또한, HGK는 cPLA₂의 인산화를 억제하며 응집 촉진물질인 TXA₂ 생성을 강하게 저해하였다. 결과적으로 응집 유도 물질인 collagen가 유도한 혈소판 응집을 86.36 µM의 IC₅₀로 강하게 억제하였다. 그러므로, 본 연구를 통해 HGK가 혈관 손상을 통해 일어나는 사람 혈소판의 활성화 및 응집을 억제하는 항혈전 물질로 가치가 있음을 분명히 하였다.