Search results for "ASK1"
showing 10 items of 18 documents
Activation of a nuclear-localized SIPK in tobacco cells challenged by cryptogein, an elicitor of plant defence reactions.
2009
When a plant cell is challenged by a well-defined stimulus, complex signal transduction pathways are activated to promote the modulation of specific sets of genes and eventually to develop adaptive responses. In this context, protein phosphorylation plays a fundamental role through the activation of multiple protein kinase families. Although the involvement of protein kinases at the plasma membrane and cytosolic levels are now well-documented, their nuclear counterparts are still poorly investigated. In the field of plant defence reactions, no known study has yet reported the activation of a nuclear protein kinase and/or its nuclear activity in plant cells, although some protein kinases, e.…
Regulation of Nicotiana tabacum osmotic stress-activated protein kinase and its cellular partner GAPDH by nitric oxide in response to salinity
2010
Several studies focusing on elucidating the mechanism of NO (nitric oxide) signalling in plant cells have highlighted that its biological effects are partly mediated by protein kinases. The identity of these kinases and details of how NO modulates their activities, however, remain poorly investigated. In the present study, we have attempted to clarify the mechanisms underlying NO action in the regulation of NtOSAK (Nicotiana tabacum osmotic stress-activated protein kinase), a member of the SNF1 (sucrose non-fermenting 1)-related protein kinase 2 family. We found that in tobacco BY-2 (bright-yellow 2) cells exposed to salt stress, NtOSAK is rapidly activated, partly through a NO-dependent pr…
Loss of cellular FLICE-inhibitory protein promotes acute cholestatic liver injury and inflammation from bile duct ligation.
2017
Cholestatic liver injury results from impaired bile flow or metabolism and promotes hepatic inflammation and fibrogenesis. Toxic bile acids that accumulate in cholestasis induce apoptosis and contribute to early cholestatic liver injury, which is amplified by accompanying inflammation. The aim of the current study was to evaluate the role of the antiapoptotic caspase 8-homolog cellular FLICE-inhibitory (cFLIP) protein during acute cholestatic liver injury. Transgenic mice exhibiting hepatocyte-specific deletion of cFLIP (cFLIP−/−) were used for in vivo and in vitro analysis of cholestatic liver injury using bile duct ligation (BDL) and the addition of bile acids ex vivo. Loss of cFLIP in h…
Diverse stress signals activate the C1 subgroup MAP kinases ofArabidopsis
2007
AbstractMitogen-activated protein kinase (MAPK) cascades play an important role in mediating stress responses in plants. In Arabidopsis, 20 MAPKs have been identified and classified into four major groups (A–D). Little is known about the role of group C MAPKs. We have studied the activation of Arabidopsis subgroup C1 MAPKs (AtMPK1/AtMPK2) in response to mechanical injury. An increase in their kinase activity was detected in response to wounding that was blocked by cycloheximide. Jasmonic acid (JA) activated AtMPK1/AtMPK2 in the absence of wounding. Wound and JA-induction of AtMPK1/2 kinase activity was not prevented in the JA-insensitive coi1 mutant. Other stress signals, such as abscisic a…
Different Genetic Expression Profiles of Oxidative Stress and Apoptosis-Related Genes in Crohn's Disease.
2018
<b><i>Background/Aims:</i></b> Increased oxidative stress and decreased immune cell apoptosis have been reported to be important factors in the pathogenesis of Crohn’s disease (CD). Our aim was to characterize the genetic expression of molecules implicated in the regulation of oxidative stress and apoptosis in peripheral white mononuclear cells of 18 healthy volunteers (controls) and 20 patients at the onset of CD (active CD [aCD]): 10 who achieved remission (inactive CD [iCD]) and 10 who did not present a complete and deep response to treatment (aCD-T). <b><i>Methods:</i></b> mRNA expression was measured by the Agena MassARRAY quantitative ge…
Protein kinase activities associated with ribosomes of developing rat brain. Identification of eukaryotic initiation factor 2 kinases.
1986
Protein kinases associated with ribosomes in the brains of suckling (4-10 days) and adult (2 months) rats were extracted from ribosomal fraction with 0.5 M KCl. The different protein kinase activities were characterized by their ability to phosphorylate three exogenous substrates: casein, histone IIs and histone IIIs in the presence of different modulators. Ribosomal salt wash fractions contain a high casein kinase activity which was partially inhibited by heparin and stimulated by calmodulin in the presence of Ca2+, indicating the presence of casein kinase I and II and calcium/calmodulin-dependent kinases. Cyclic AMP and cyclic GMP-dependent kinases and protein kinase C (calcium/phospholip…
Differential role of p38 mitogen activated protein kinase for cellular recovery from attack by pore-forming S. aureus alpha-toxin or streptolysin O.
2006
Following the observation that cells are able to recover from membrane lesions incurred by Staphylococcus aureus alpha-toxin and streptolysin O (SLO), we investigated the role of p38 in this process. p38 phosphorylation occurred in response to attack by both toxins, commencing within minutes after toxin treatment and waning after several hours. While SLO reportedly activates p38 via ASK1 and ROS, we show that this pathway does not play a major role for p38 induction in alpha-toxin-treated cells. Strikingly divergent effects of p38 blockade were noted depending on the toxin employed. In the case of alpha-toxin, inhibition of p38 within the time frame of its activation led to disruption of th…
Tumor Necrosis Factor (TNF) Receptor 1 Signaling Downstream of TNF Receptor-associated Factor 2
1997
Like other members of the tumor necrosis factor (TNF) receptor family, p55 TNF receptor 1 (TNF-R1) lacks intrinsic signaling capacity and transduces signals by recruiting associating molecules. The TNF-R1 associated death domain protein interacts with the p55 TNF-R1 cytoplasmic domain and recruits the Fas-associated death domain protein (which directly activates the apoptotic proteases), the protein kinase receptor interacting protein, and TNF receptor-associated factor 2 (TRAF2). TRAF2 has previously been demonstrated to activate both transcription factor nuclear factor kappaB (NFkappaB) and the c-Jun N-terminal kinase/stress-activated protein kinase (JNK/SAPK) pathway, which in turn stimu…
The neuropeptide PACAP promotes ?‐secretase pathway for processing Alzheimer amyloid precursor protein
2006
SPECIFIC AIMSProteolytic cleavage of the amyloid precursor protein (APP) by α-secretase within the Aβ sequence precludes formation of amyloidogenic peptides and leads to a release of soluble APPsα,...
Activation of Cardiac c-Jun NH 2 -Terminal Kinases and p38-Mitogen–Activated Protein Kinases With Abrupt Changes in Hemodynamic Load
2001
Abstract —The role of mitogen-activated protein kinase (MAPK) pathways as signal transduction intermediates of hemodynamic stress leading to cardiac hypertrophy in the adult heart is not fully established. In a rat model of pressure-overload hypertrophy, we examined whether activation of MAPK pathways, namely, the extracellular signal–regulated protein kinase (ERK), c-Jun NH 2 -terminal kinase (JNK), and the p38-MAPK pathways, occurs during rapid changes in hemodynamic load in vivo. A slight activation of ERK2 and marked increases in JNK1 and p38-MAPK activities were observed 30 minutes after aortic banding. The increase in p38-MAPK activity was accompanied by an increase in the phosphoryl…