scholarly journals MAPK Pathway under Chronic Copper Excess in Green Macroalgae (Chlorophyta): Involvement in the Regulation of Detoxification Mechanisms

2019 ◽  
Vol 20 (18) ◽  
pp. 4546 ◽  
Author(s):  
Fernanda Rodríguez-Rojas ◽  
Paula S. M. Celis-Plá ◽  
Lorena Méndez ◽  
Fabiola Moenne ◽  
Pamela T. Muñoz ◽  
...  

Following the physiological complementary/parallel Celis-Plá et al., by inhibiting extracellular signal regulated kinases (ERK), c-Jun N-terminal kinases (JNK), and cytokinin specific binding protein (p38), we assessed the role of the mitogen-activated protein kinases (MAPK) pathway in detoxification responses mediated by chronic copper (10 µM) in U. compressa. Parameters were taken at 6, 24, and 48 h, and 6 days (d). H2O2 and lipid peroxidation under copper and inhibition of ERK, JNK, or p38 alone increased but recovered by the sixth day. By blocking two or more MAPKs under copper, H2O2 and lipid peroxidation decayed even below controls. Inhibition of more than one MAPK (at 6 d) caused a decrease in total glutathione (reduced glutathione (GSH) + oxidised glutathione (GSSG)) and ascorbate (reduced ascorbate (ASC) + dehydroascorbate (DHA)), although in the latter it did not occur when the whole MAPK was blocked. Catalase (CAT), superoxide dismutase (SOD), thioredoxin (TRX) ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), and glutathione synthase (GS), were downregulated when blocking more than one MAPK pathway. When one MAPK pathway was blocked under copper, a recovery and even enhancement of detoxification mechanisms was observed, likely due to crosstalk within the MAPKs and/or other signalling processes. In contrast, when more than one MAPK pathway were blocked under copper, impairment of detoxification defences occurred, demonstrating that MAPKs were key signalling mechanisms for detoxification in macroalgae.

2008 ◽  
Vol 115 (7) ◽  
pp. 203-218 ◽  
Author(s):  
Anthony J. Muslin

Intracellular MAPK (mitogen-activated protein kinase) signalling cascades probably play an important role in the pathogenesis of cardiac and vascular disease. A substantial amount of basic science research has defined many of the details of MAPK pathway organization and activation, but the role of individual signalling proteins in the pathogenesis of various cardiovascular diseases is still being elucidated. In the present review, the role of the MAPKs ERK (extracellular signal-regulated kinase), JNK (c-Jun N-terminal kinase) and p38 MAPK in cardiac hypertrophy, cardiac remodelling after myocardial infarction, atherosclerosis and vascular restenosis will be examined, with attention paid to genetically modified murine model systems and to the use of pharmacological inhibitors of protein kinases. Despite the complexities of this field of research, attractive targets for pharmacological therapy are emerging.


2006 ◽  
Vol 73 ◽  
pp. 121-129 ◽  
Author(s):  
Shen-Hsi Yang ◽  
Andrew D. Sharrocks

The ETS-domain transcription factor Elk-1 is regulated by phosphorylation in response to activation of the MAPK (mitogen-activated protein kinase) pathways. This phosphorylation triggers a series of molecular events that convert Elk-1 from a transcriptionally silent state into a highly active state and then back to a basal level. At the same time, activation of the ERK (extracellular-signal-regulated kinase) MAPK pathway leads to loss of modification of Elk-1 by SUMO (small ubiquitin-related modifier). As SUMO imparts repressive properties on Elk-1, ERK-mediated SUMO loss leads to de-repression at the same time as the ERK pathway promotes activation of Elk-1. Thus a two-step mechanism is employed to convert Elk-1 into its fully activated state. Here, the molecular events underlying these changes in Elk-1 status, and the role of PIASxα [protein inhibitor of activated STAT (signal transducer and activator of transcription) xα] as a co-activator that facilitates this process, are discussed.


2021 ◽  
Author(s):  
Saara-Anne Azizi ◽  
Tian Qiu ◽  
Noah Brookes ◽  
Bryan C Dickinson

The extracellular signal-regulated kinases (ERK1/2) are key effector proteins of the mitogen activated protein kinase pathway, choreographing essential processes of cellular physiology. Critical in regulating these regulators are a patchwork of mechanisms, including post-translational modifications (PTMs) such as MEK-mediated phosphorylation. Here, we discover that ERK1/2 are subject to S-palmitoylation, a reversible lipid modification of cysteine residues, at C271/C254. Moreover, the levels of ERK1/2 S-acylation are modulated by epidermal growth factor (EGF) signaling, mirroring its phosphorylation dynamics, and palmitoylation-deficient ERK2 displays altered phosphorylation patterns at key sites. We find that chemical inhibition of either lipid addition or removal significantly alters ERK1/2's EGF-triggered transcriptional program. We also identify a subset of "writer" protein acyl transferases (PATs) and an "eraser" acyl protein thioesterase (APT) that drive ERK1/2's cycle of palmitoylation and depalmitoylation. Finally, we examine ERK1/2 S-acylation in a mouse model of metabolic syndrome, correlating changes in its lipidation levels with alterations in writer/eraser expression and solidifying the link between ERK1/2 activity, ERK1/2 lipidation, and organismal health. This study not only presents a previously undescribed mode of ERK1/2 regulation and a node to modulate MAPK pathway signaling in pathophysiological conditions, it also offers insight into the role of dynamic S29 palmitoylation in cell signaling more generally.


2012 ◽  
Vol 40 (1) ◽  
pp. 251-256 ◽  
Author(s):  
Pamela A. Lochhead ◽  
Rebecca Gilley ◽  
Simon J. Cook

The MEK5 [MAPK (mitogen-activated protein kinase)/ERK (extracellular-signal-regulated kinase) kinase 5]/ERK5 pathway is the least well studied MAPK signalling module. It has been proposed to play a role in the pathology of cancer. In the present paper, we review the role of the MEK5/ERK5 pathway using the ‘hallmarks of cancer’ as a framework and consider how this pathway is deregulated. As well as playing a key role in endothelial cell survival and tubular morphogenesis during tumour neovascularization, ERK5 is also emerging as a regulator of tumour cell invasion and migration. Several oncogenes can stimulate ERK5 activity, and protein levels are increased by a novel amplification at chromosome locus 17p11 and by down-regulation of the microRNAs miR-143 and miR-145. Together, these finding underscore the case for further investigation into understanding the role of ERK5 in cancer.


2019 ◽  
Vol 20 (6) ◽  
pp. 1426 ◽  
Author(s):  
Barbara Stecca ◽  
Elisabetta Rovida

Extracellular signal-regulated kinase 5 (ERK5) belongs to the mitogen-activated protein kinase (MAPK) family that consists of highly conserved enzymes expressed in all eukaryotic cells and elicits several biological responses, including cell survival, proliferation, migration, and differentiation. In recent years, accumulating lines of evidence point to a relevant role of ERK5 in the onset and progression of several types of cancer. In particular, it has been reported that ERK5 is a key signaling molecule involved in almost all the biological features of cancer cells so that its targeting is emerging as a promising strategy to suppress tumor growth and spreading. Based on that, in this review, we pinpoint the hallmark-specific role of ERK5 in cancer in order to identify biological features that will potentially benefit from ERK5 targeting.


2001 ◽  
Vol 69 (5) ◽  
pp. 3143-3149 ◽  
Author(s):  
S. Bonner ◽  
S. R. Yan ◽  
D. M. Byers ◽  
R. Bortolussi

ABSTRACT Neutrophils exposed to low concentrations of gram-negative lipopolysaccharide (LPS) become primed and have an increased oxidative response to a second stimulus (e.g., formyl-methionyl-leucyl-phenylalanine [fMLP]). In studies aimed at understanding newborn sepsis, we have shown that neutrophils of newborns are not primed in response to LPS. To further understand the processes involved in LPS-mediated priming of neutrophils, we explored the role of extracellular signal-related protein kinases (ERK 1 and 2) of the mitogen-activated protein kinase family. We found that LPS activated ERK 1 and 2 in cells of both adults and newborns and that activation was plasma dependent (maximal at ≥5%) through LPS-binding protein. Although fibronectin in plasma is required for LPS-mediated priming of neutrophils of adults assessed by fMLP-triggered oxidative burst, it was not required for LPS-mediated activation of ERK 1 and 2. LPS-mediated activation was dose and time dependent; maximal activation occurred with approximately 5 ng of LPS per ml and at 10 to 40 min. We used the inhibitor PD 98059 to study the role of ERK 1 and 2 in the LPS-primed fMLP-triggered oxidative burst. While Western blotting showed that 100 μM PD 98059 completely inhibited LPS-mediated ERK activation, oxidative response to fMLP by a chemiluminescence assay revealed that the same concentration inhibited the LPS-primed oxidative burst by only 40%. We conclude that in neutrophils, LPS-mediated activation of ERK 1 and 2 requires plasma and that this activation is not dependent on fibronectin. In addition, we found that the ERK pathway is not responsible for the lack of LPS priming in neutrophils of newborns but may be required for 40% of the LPS-primed fMLP-triggered oxidative burst in cells of adults.


Sign in / Sign up

Export Citation Format

Share Document