• BMB Reports
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• v.43 no.11
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• pp.738-743
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• 2010

The c-Jun $NH_2$-terminal kinase (JNK) signaling pathway participates in many physiological functions. In the current study we reported the cloning and characterization of five novel JNK2 transcript variants, which were designated as $JNK2\alpha3$, $JNK2\alpha4$, $JNK2\beta3$, $JNK2\gamma1$ and $JNK2\gamma2$, respectively. Among them, $JNK2\alpha4$ and $JNK2\gamma2$ are potential non-coding RNA because they contain pre-mature stop codons. Both $JNK2\alpha3$ and $JNK2\beta3$ contain an intact kinase domain, and both encode a protein product of 46 kDa, the same as those of $JNK2\alpha1$ and $JNK2\beta1$. $JNK2\gamma1$ contains a disrupted kinase domain and it showed a disable function. When over-expressed in mammalian cells, $JNK2\alpha3$ showed higher activity on AP-1 than that of $JNK2\beta3$ and $JNK2\gamma1$. Furthermore, $JNK2\alpha3$ and $JNK2\beta3$ showed different levels of substrate phosphorylation, although they both could promote the proliferation of 293T cells. Our results further demonstrate that JNK2 isoforms preferentially target different substrates and may regulate the expression of various target genes.

• Molecules and Cells
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• v.28 no.6
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• pp.509-513
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• 2009

Here, we show that JNK1 and JNK3 have different roles in ${\alpha}-$ or etoposide-induced apoptosis in HeLa cells. Dominant negative JNK1 inhibited $TNF-{\alpha}-$ or etoposide-induced apoptosis, while dominant negative JNK3 promoted $TNF-{\alpha}-$ or etoposide-induced apoptosis. During $TNF-{\alpha}$-induced apoptosis, JNK1 was activated in a biphasic manner, exhibiting both transient and sustained activity, whereas JNK3 was activated early and in a transient manner. The role of JNK3 activation was an anti-apoptotic effect, while the role of JNK1 activation was a pro-apoptotic effect. These results suggest that the anti-apoptotic mechanism of JNK3 in $TNF-{\alpha}$-induced apoptosis originates before the apoptotic machinery is triggered.

• Journal of the Korean Magnetic Resonance Society
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• v.16 no.1
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• pp.67-77
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• 2012

The small molecule binding to the c-Jun N-terminal kinase 3 (JNK3) was examined by the measurements of saturation transfer difference (STD) NMR experiments. The STD NMR experiment of ATP added to JNK3 clearly showed the binding of the nucleotide to the kinase. The STD NMR spectrum of dNTPs added to JNK3 discriminated the kinase-bound nucleotide from the unbound ones. After the five-fold addition of ATP to the dNTPs and JNK3 mixture, only signals of the cognate substrate of JNK3, ATP, were observed from the STD NMR experiment. These results signify that by the STD NMR the small molecules bound to JNK3 can be discriminated from the pool of the unbound molecules. Furthermore the binding mode of the small molecule to JNK3 can be determined by the competition experiments with ATP.

• Journal of Integrative Natural Science
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• v.15 no.4
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• pp.179-186
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• 2022

The c-Jun N-terminal kinase (JNK3) play major role in neurodegenerative diseases like Alzheimer's disease, Parkinson's disease, cerebral ischemia and other Central Nervous System disorders. Since JNK3 is primarily stated in the brain and stimulated by stress-stimuli, this situation is conceivable that inhibiting JNK3 could be a possible treatment for the mechanisms underlying neurodegenerative diseases. In this study drugs from Zinc15 database were screened to identify the JNK3 inhibitors by Molecular docking and Density functional theory approach. Molecular docking was done by Autodock vina and the ligands were selected based on the binding affinity. Our results identified top ten novel ligands as potential inhibitors against JNK3. Molecular docking revealed that Venetoclax, Fosaprepitant and Avapritinib exhibited better binding affinity and interacting with proposed binding site residues of JNK3. Density functional theory was used to compute the values for energy gap, lowest unoccupied molecular orbital (LUMO), and highest occupied molecular orbital (HOMO). The results of Density functional theory study showed that Venetoclax, Fosaprepitant and Avapritinib serves as a lead compound for the development of JNK3 small molecule inhibitors.

• Biomedical Science Letters
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• v.27 no.3
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• pp.134-141
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• 2021

c-Jun N-terminal kinases (JNKs) have a Janus face, regulating both cell apoptosis and survival. The present study focused on understanding the function of JNK in tumor development and the chemoresistance underlying JNK-mediated cancer cell survival. We identified an inhibitor of JNK1, an important regulator of cancer cell survival. Kinase assay data showed that JNK1-dependent c-Jun phosphorylation was inhibited by indirubin derivatives. In particular, indirubin-3-monoxime (I3M) directly inhibited the phosphorylation of c-Jun in vitro, with a half inhibition dose (IC₅₀) of 10 nM. I3M had a significant inhibitory effect on JNK1 activity. Furthermore, we carried out assays to determine the viability, migration, and proliferation of breast cancer cells. Our results demonstrated that cell growth, scratched wound healing, and colony forming abilities were inhibited by the JNK inhibitor SP600125 and I3M. The combination of SP600125 and I3M significantly decreased cancer cell proliferation, compared with either SP600125 or I3M alone. Our studies may provide further support for JNK1-targeting cancer therapy using the indirubin derivative I3M in breast cancer.

• Tuberculosis and Respiratory Diseases
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• v.57 no.5
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• pp.449-460
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• 2004

Background : PS-341 is a novel, highly selective and potent proteasome inhibitor, which showed cytotoxicity against some tumor cells. Its anti-tumor activity has been suggested to be associated with modulation of the expression of apoptosis-associated proteins, such as p53, $p21^{WAF/CIP1}$, $p27^{KIP1}$, NF-${\kappa}B$, Bax and Bcl-2. c-Jun N-terminal kinase (JNK) and glycogen synthase kinase-$3{\beta}$ (GSK-$3{\beta}$) are important modulators of apoptosis. However, their role in PS-341-induced apoptosis is unclear. This study was undertaken to elucidate the role of JNK and GSK-$3{\beta}$ in the PS-341-induced apoptosis in lung cancer cells. Method : NCI-H157 and A549 cells were used in the experiments. The cell viability was assayed using the MTT assay and apoptosis was evaluated by proteolysis of PARP. The JNK activity was measured by an in vitro immuno complex kinase assay and by phosphorylation of endogenous c-Jun. The protein expression was evaluated by Western blot analysis. Dominant negative JNK1 (DN-JNK1) and GSK-$3{\beta}$ were overexpressed using plasmid and adenovirus vectors, respectively. Result : PS-341 reduced the cell viability via apoptosis, activated JNK and increased the c-Jun expression. Blocking of the JNK activation by overexpression of DN-JNK1, or pretreatment with SP600125, suppressed the apoptosis induced by PS-341. The activation of caspase 3 was mediated by JNK activation. Blocking of the caspase 3 activation suppressed PS-341-induced apoptosis. PS-341 activated the phosphatidylinositol 3-kinase (PI3K)/Akt pathway, but its blockade enhanced the PS-341-induced cell death via apoptosis. GSK-$3{\beta}$ was inactivated by PS-341 via the PI3K/Akt pathway. Overexpression of constitutively active GSK-$3{\beta}$ enhanced PS-341-induced apoptosis; in contrast, this was suppressed by dominant negative GSK-$3{\beta}$ (DN-GSK-$3{\beta}$). Inactivation of GSK-$3{\beta}$ by pretreatment with lithium chloride or the overexpression of DN-GSK-$3{\beta}$ suppressed both the JNK activation and c-Jun up-regulation induced by PS-341. Conclusion : The JNK/caspase pathway is involved in PS-341-induced apoptosis, which is negatively regulated by the PI3K/Akt-mediated inactivation of GSK-$3{\beta}$ in lung cancer cells.

• Bulletin of the Korean Chemical Society
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• v.31 no.8
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• pp.2147-2150
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• 2010

c-Jun N-terminal kinase 1 (JNK1) is involved in apoptosis, cell differentiation and proliferation. It has been reported that a flavonol, quercetin, induces cell apoptosis and JNK inhibition. In order to understand the interactions of quercetin and JNK1, we performed receptor-oriented pharmacophore based in silico screening and determined a binding model of human JNK1 and quercetin at the ATP binding site of JNK1. 5-OH of A-ring and carbonyl oxygen of C-ring of quercetin participated in hydrogen bonding interactions with backbone of E109 and M111. Additionally, 3'-OH of quercetin formed a hydrogen bond with backbone of I32. One hydrophobic interaction is related on the binding of quercetin to JNK1 with I32, N114, and V158. Based on this model, we conducted a docking study with other 8 flavonols to find possible flavonoids inhibitors of JNK1. We proposed that one flavonols, rhamnetin, can be a potent inhibitor of JNK and 5-OH of A-ring and 3'-OH of B-ring of flavonols are the essential features for JNK1 inhibition.

• Journal of Integrative Natural Science
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• v.8 no.2
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• pp.81-88
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• 2015

c-Jun N-terminal kinase-3 (JNK3) is a member of the mitogen-activated protein kinase family (MAPK), and plays an important role in neurological disorders. Therefore, identification of selective JNK3 inhibitor may contribute towards neuroprotection therapies. In this work, we performed hologram quantitative structure-activity relationship (HQSAR) on a series of thiophene trisubstituted derivatives. The best predictions were obtained for HQSAR model with $q^2=0.628$ and $r^2=0.986$. Statistical parameters from the generated QSAR models indicated the data is well fitted and have high predictive ability. HQSAR result showed that atom, bond and chirality descriptors play an important role in JNK3 activity and also shows that electronegative groups is highly favourble to enhance the biological activity. Our results could be useful to design novel and selective JNK3 inhibitors.

• Journal of Integrative Natural Science
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• v.5 no.1
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• pp.6-12
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• 2012

c-Jun N-terminal kinase-3 (JNK-3) has been identified as a promising target for neuronal apoptosis and has the effective therapeutic for neurodegenerative diseases such as Parkinson's disease, Alzheimer's disease, and other CNS disorders. Herein, we report the essential structural and chemical parameters for JNK-3 inhibitors utilizing comparative molecular field similarity indices analysis (CoMSIA) using the derivatives of 3,5-disubstituted quinolines. The best predictions were obtained CoMSIA model (q2=0.834, r2=0.987) and the statistical parameters from the generated 3D-QSAR models were indicated that the data are well fitted and have high predictive ability. The resulting contour map from 3D-QSAR models might be helpful to design novel and more potent JNK3 derivatives.

• Journal of Integrative Natural Science
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• v.7 no.1
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• pp.45-49
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• 2014

The (c-Jun N-terminal kinase 3) JNK3 is a potential therapeutic target for various neurological disorders. Here, a three dimensional quantitative structure-activity relationship (3D-QSAR) study on phenoxypyridine as JNK3 inhibitors was performed to rationalize the structural requirements responsible for the inhibitory activity of these compounds. The comparative molecular field analysis (CoMFA) using different partial atomic charges, was employed to understand the structural factors affecting JNK3 inhibitory potency. The Gasteiger-Marsili yielded a CoMFA model with cross-validated correlation coefficient ($q^2$) of 0.54 and non-cross-validated correlation coefficient ($r^2$) of 0.93 with five components. Furthermore, contour maps suggested that bulky substitution with oxygen atom in $R^3$ position could enhance the activity considerably. The work suggests that further chemical modifications of the compounds could lead to enhanced activity and could assist in the design of novel JNK3 inhibitors.