scholarly journals Impact of Conventional and Atypical MAPKs on the Development of Metabolic Diseases

Biomolecules ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1256
Author(s):  
Toufic Kassouf ◽  
Grzegorz Sumara

The family of mitogen-activated protein kinases (MAPKs) consists of fourteen members and has been implicated in regulation of virtually all cellular processes. MAPKs are divided into two groups, conventional and atypical MAPKs. Conventional MAPKs are further classified into four sub-families: extracellular signal-regulated kinases 1/2 (ERK1/2), c-Jun N-terminal kinase (JNK1, 2 and 3), p38 (α, β, γ, δ), and extracellular signal-regulated kinase 5 (ERK5). Four kinases, extracellular signal-regulated kinase 3, 4, and 7 (ERK3, 4 and 7) as well as Nemo-like kinase (NLK) build a group of atypical MAPKs, which are activated by different upstream mechanisms than conventional MAPKs. Early studies identified JNK1/2 and ERK1/2 as well as p38α as a central mediators of inflammation-evoked insulin resistance. These kinases have been also implicated in the development of obesity and diabetes. Recently, other members of conventional MAPKs emerged as important mediators of liver, skeletal muscle, adipose tissue, and pancreatic β-cell metabolism. Moreover, latest studies indicate that atypical members of MAPK family play a central role in the regulation of adipose tissue function. In this review, we summarize early studies on conventional MAPKs as well as recent findings implicating previously ignored members of the MAPK family. Finally, we discuss the therapeutic potential of drugs targeting specific members of the MAPK family.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Haiyan Zhou ◽  
Xinyi Peng ◽  
Jie Hu ◽  
Liwen Wang ◽  
Hairong Luo ◽  
...  

AbstractAdipose tissue-resident T cells have been recognized as a critical regulator of thermogenesis and energy expenditure, yet the underlying mechanisms remain unclear. Here, we show that high-fat diet (HFD) feeding greatly suppresses the expression of disulfide-bond A oxidoreductase-like protein (DsbA-L), a mitochondria-localized chaperone protein, in adipose-resident T cells, which correlates with reduced T cell mitochondrial function. T cell-specific knockout of DsbA-L enhances diet-induced thermogenesis in brown adipose tissue (BAT) and protects mice from HFD-induced obesity, hepatosteatosis, and insulin resistance. Mechanistically, DsbA-L deficiency in T cells reduces IFN-γ production and activates protein kinase A by reducing phosphodiesterase-4D expression, leading to increased BAT thermogenesis. Taken together, our study uncovers a mechanism by which T cells communicate with brown adipocytes to regulate BAT thermogenesis and whole-body energy homeostasis. Our findings highlight a therapeutic potential of targeting T cells for the treatment of over nutrition-induced obesity and its associated metabolic diseases.


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.


2003 ◽  
Vol 23 (13) ◽  
pp. 4542-4558 ◽  
Author(s):  
Philippe Coulombe ◽  
Geneviève Rodier ◽  
Stéphane Pelletier ◽  
Johanne Pellerin ◽  
Sylvain Meloche

ABSTRACT Mitogen-activated protein (MAP) kinases are stable enzymes that are mainly regulated by phosphorylation and subcellular targeting. Here we report that extracellular signal-regulated kinase 3 (ERK3), unlike other MAP kinases, is an unstable protein that is constitutively degraded in proliferating cells with a half-life of 30 min. The proteolysis of ERK3 is executed by the proteasome and requires ubiquitination of the protein. Contrary to other protein kinases, the catalytic activity of ERK3 is not responsible for its short half-life. Instead, analysis of ERK1/ERK3 chimeras revealed the presence of two destabilization regions (NDR1 and -2) in the N-terminal lobe of the ERK3 kinase domain that are both necessary and sufficient to target ERK3 and heterologous proteins for proteasomal degradation. To assess the physiological relevance of the rapid turnover of ERK3, we monitored the expression of the kinase in different cellular models of differentiation. We observed that ERK3 markedly accumulates during differentiation of PC12 and C2C12 cells into the neuronal and muscle lineage, respectively. The accumulation of ERK3 during myogenic differentiation is associated with the time-dependent stabilization of the protein. Terminal skeletal muscle differentiation is accompanied by cell cycle withdrawal. Interestingly, we found that expression of stabilized forms of ERK3 causes G1 arrest in NIH 3T3 cells. We propose that ERK3 biological activity is regulated by its cellular abundance through the control of protein stability.


1998 ◽  
Vol 188 (7) ◽  
pp. 1297-1306 ◽  
Author(s):  
Aimin Jiang ◽  
Andrew Craxton ◽  
Tomohiro Kurosaki ◽  
Edward A. Clark

B cell antigen receptor (BCR) cross-linking activates three distinct families of nonreceptor protein tyrosine kinases (PTKs): src-family kinases, Syk, and Btk; these PTKs are responsible for initiating downstream events. BCR cross-linking in the chicken DT40 B cell line also activates three distinct mitogen-activated protein kinases (MAPKs): extracellular signal–regulated kinase (ERK)2, c-jun NH2-terminal kinase (JNK)1, and p38 MAPK. To dissect the functional roles of these PTKs in MAPK signaling, activation of MAPKs was examined in various PTK-deficient DT40 cells. BCR-mediated activation of ERK2, although maintained in Lyn-deficient cells, was abolished in Syk-deficient cells and partially inhibited in Btk-deficient cells, indicating that BCR-mediated ERK2 activation requires Syk and that sustained ERK2 activation requires Btk. BCR-mediated JNK1 activation was maintained in Lyn-deficient cells but abolished in both Syk- and Btk-deficient cells, suggesting that JNK1 is activated via a Syk- and Btk-dependent pathway. Consistent with this, BCR-mediated JNK1 activation was dependent on intracellular calcium and phorbol myristate acetate–sensitive protein kinase Cs. In contrast, BCR-mediated p38 MAPK activation was detected in all three PTK-deficient cells, suggesting that no single PTK is essential. However, BCR-mediated p38 MAPK activation was abolished in Lyn/Syk double deficient cells, demonstrating that either Lyn or Syk alone may be sufficient to activate p38 MAPK. Our data show that BCR-mediated MAPK activation is regulated at the level of the PTKs.


Author(s):  
Andreas Gewies ◽  
Jürgen Ruland ◽  
Alexey Kotlyarov ◽  
Matthias Gaestel ◽  
Shiri Procaccia ◽  
...  

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