The constitutive activation of JNK has been implicated in Ras-induced cellular transformation and activated JNK is down-regulated by the tumor suppressor protein, RASSF1A. In this study, we examined whether RASSF1A blocked oncogenic Ras-induced JNK activation. Exogenous expression of H-RasG12V induced JNK phosphorylation and RASSF1A co-transfected with H-RasG12V efficiently suppressed Ras-trigg...

The c-Jun N-terminal protein kinase (JNK) signaling pathway is implicated in neuronal apoptosis. The mechanism by which activated JNK induces neuronal apoptosis is strongly linked to mitochondrial apoptogenic proteins, although the molecular machinery downstream of JNK has not been precisely elucidated. Our study examined the relevance of proapoptotic Bcl-2 family members in JNKmediated apoptos...

The c-Jun N-terminal kinase (JNK) is part of a stress signalling pathway strongly activated by NMDA-stimulation and involved in synaptic plasticity. Many studies have been focused on the post-synaptic mechanism of JNK action, and less is known about JNK presynaptic localization and its physiological role at this site. Here we examined whether JNK is present at the presynaptic site and its activ...

In this study, phosphorylation of c-Jun N-terminal kinase (JNK) by the prothoracicotropic hormone (PTTH) was investigated in prothoracic glands (PGs) of the silkworm, Bombyx mori. Results showed that JNK phosphorylation was stimulated by the PTTH in time- and dose-dependent manners. In vitro activation of JNK phosphorylation in PGs by the PTTH was also confirmed in an in vivo experiment, in whi...

BACKGROUND Mounting evidence points to individual contributions of tumour necrosis factor-alpha (TNF) and the c-Jun N-terminal kinase (JNK) pathway to the induction and maintenance of various pain states. Here we explore the role of spinal TNF and JNK in carrageenan-induced hypersensitivity. As links between TNF and JNK have been demonstrated in vitro, we investigated if TNF regulates spinal JN...

The c-Jun amino-terminal kinase (JNK) proteins are a subgroup of the mitogen-activated protein kinase family. They play a complex role in cell proliferation, survival, and apoptosis. Here, we report a novel role of JNK signalling in hair cell regeneration. We eliminated hair cells of 5-day post-fertilization zebrafish larvae using neomycin followed by JNK inhibition with SP600125. JNK inhibitio...

Exposure of primary murine embryonic fibroblasts to tumor necrosis factor (TNF) causes biphasic activation of the c-Jun NH(2)-terminal kinase (JNK) signaling pathway. The early phase (30 min) of the response to TNF is a large and transient increase in JNK activity. This response is followed by a second and more sustained phase of JNK activation that lasts many hours. We employed a chemical gene...

We report here the cleavage of the c-Jun N-terminal Kinase (JNK) pathway scaffold protein, JNK Interacting Protein-1 (JIP1), by caspases during both Tumour Necrosis Factor-Related Apoptosis-Inducing Ligand (TRAIL) and staurosporine-induced apoptosis in HeLa cells. During the initiation of apoptosis, maximal JNK activation is observed when JIP1 is intact, whereas cleavage of JIP1 correlates with...

Hyperactivation of c-Jun NH2-terminal protein kinase (JNK) has been found in various malignant lymphocytes and inhibition of JNK activity leads to cell cycle arrest and apoptosis. However, the role of JNK activity in the oncogenic growth of T-cell acute lymphoblastic leukemia (T-ALL) cells remains largely unknown. Here, we report that treatment of T-ALL cells with JNK inhibitors led to cell cyc...

JIP1 is a scaffold protein that assembles and facilitates the activation of the mixed lineage kinase-dependent JNK module. Results of earlier work led us to propose a model for JIP1-JNK complex regulation that predicts that under basal conditions, JIP1 maintains DLK in a monomeric, unphosphorylated, and catalytically inactive state. Upon appropriate module stimulation, JNK-JIP1 binding affinity...