scholarly journals Parallel feedback loops control the basal activity of the HOG MAPK signaling cascade

2015 ◽  
Vol 7 (4) ◽  
pp. 412-422 ◽  
Author(s):  
Hoda Sharifian ◽  
Fabienne Lampert ◽  
Klement Stojanovski ◽  
Sergi Regot ◽  
Stefania Vaga ◽  
...  

Hog1-dependent feedback inhibits the Sln1 branch by directly phosphorylating Ssk2 and components of the sensory module.

2019 ◽  
Vol 96 (1) ◽  
pp. 36-46 ◽  
Author(s):  
Kathryn E. Cronise ◽  
Belen G. Hernandez ◽  
Daniel L. Gustafson ◽  
Dawn L. Duval

2020 ◽  
Vol 21 (7) ◽  
pp. 2346 ◽  
Author(s):  
Jicheng Yue ◽  
José M. López

MAPK (mitogen-activated protein kinase) signaling pathways regulate a variety of biological processes through multiple cellular mechanisms. In most of these processes, such as apoptosis, MAPKs have a dual role since they can act as activators or inhibitors, depending on the cell type and the stimulus. In this review, we present the main pro- and anti-apoptotic mechanisms regulated by MAPKs, as well as the crosstalk observed between some MAPKs. We also describe the basic signaling properties of MAPKs (ultrasensitivity, hysteresis, digital response), and the presence of different positive feedback loops in apoptosis. We provide a simple guide to predict MAPKs’ behavior, based on the intensity and duration of the stimulus. Finally, we consider the role of MAPKs in osmostress-induced apoptosis by using Xenopus oocytes as a cell model. As we will see, apoptosis is plagued with multiple positive feedback loops. We hope this review will help to understand how MAPK signaling pathways engage irreversible cellular decisions.


Biomolecules ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 199 ◽  
Author(s):  
Md Badrul Alam ◽  
Nargis Sultana Chowdhury ◽  
Md Hossain Sohrab ◽  
Md Sohel Rana ◽  
Choudhury Mahmood Hasan ◽  
...  

As part of our continuous effort to find potential anti-inflammatory agents from endophytic fungi, a Fusarium solani strain, isolated from the plant Aponogeton undulatus Roxb., was investigated. Cerevisterol (CRVS) was identified from endophytic fungi, a Fusarium solani strain, and moreover exhibited anti-inflammatory activity. However, the underlying mode of action remains poorly understood. The aim of this study is to reveal the potential mechanisms of CRVS against inflammation on a molecular level in LPS-activated RAW 264.7 peritoneal macrophage cells. CRVS was isolated from F. solani and characterized based on spectral data analysis. The MTT assay was performed to measure cell viability in CRVS-treated macrophages. Anti-inflammatory activity was assessed by measurement of nitric oxide (NO) and prostaglandin E2 (PGE2) levels, as well as the production of various cytokines, such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and -6 (IL-6) in LPS-stimulated macrophages. RT-PCR and immunoblotting analyses were done to examine the expression of various inflammatory response genes. A reporter gene assay was conducted to measure the level of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and activator protein-1 (AP-1) transactivation. CRVS suppresses the LPS-induced production of NO and PGE2, which is a plausible mechanism for this effect is by reducing the expression of iNOS and COX-2. CRVS also decreases the expression of pro-inflammatory cytokines, such as TNF-α, IL-6, and IL-1β. CRVS halted the nuclear translocation of NF-κB by blocking the phosphorylation of inhibitory protein κBα (IκBα) and suppressing NF-κB transactivation. The mitogen-activated protein kinases (MAPK) signaling pathways are also suppressed. CRVS treatment also inhibited the transactivation of AP-1 and the phosphorylation of c-Fos. Furthermore, CRVS could induce the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) by down-regulating Kelch-like ECH-associated protein 1 (Keap-1) and up-regulating hemeoxygenases-1 (HO-1) expression. The results suggest that CRVS acts as a natural agent for treating inflammatory diseases by targeting an MAPK, NF-κB, AP-1, and Nrf2-mediated HO-1 signaling cascade.


Cancers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 490 ◽  
Author(s):  
Qiu-Ping Liu ◽  
Qing Luo ◽  
Bin Deng ◽  
Yang Ju ◽  
Guan-Bin Song

Increased extracellular matrix (ECM) stiffness and metabolic reprogramming of cancer cells are two fundamental mediators of tumor progression, including hepatocellular carcinoma (HCC). Yet, the correlation between ECM stiffness and excessive aerobic glycolysis in promoting the development of HCC remains unknown. Here, we demonstrated that stiffer ECM promotes HCC cell migration depending on their accelerated aerobic glycolysis. Our results also indicated that stiffer ECM-induced YAP activation plays a major role in promoting aerobic glycolysis of HCC cells. Moreover, we showed that JNK and p38 MAPK signaling are critical for mediating YAP activation in HCC cells. Together, our findings established that the MAPK-YAP signaling cascade that act as a mechanotransduction pathway is essential for promoting HCC cell aerobic glycolysis and migration in response to ECM stiffness.


2002 ◽  
Vol 22 (21) ◽  
pp. 7593-7602 ◽  
Author(s):  
Amy M. Delaney ◽  
John A. Printen ◽  
Huifen Chen ◽  
Eric B. Fauman ◽  
David T. Dudley

ABSTRACT Utilizing a genetic screen in the yeast Saccharomyces cerevisiae, we identified a novel autoactivation region in mammalian MEK1 that is involved in binding the specific MEK inhibitor, PD 184352. The genetic screen is possible due to the homology between components of the yeast pheromone response pathway and the eukaryotic Raf-MEK-ERK signaling cascade. Using the FUS1::HIS3 reporter as a functional readout for activation of a reconstituted Raf-MEK-ERK signaling cascade, randomly mutagenized MEK variants that were insensitive to PD 184352 were obtained. Seven single-base-change mutations were identified, five of which mapped to kinase subdomains III and IV of MEK. Of the seven variants, only one, a leucine-to-proline substitution at amino acid 115 (Leu115Pro), was completely insensitive to PD 184352 in vitro (50% inhibitory concentration >10 μM). However, all seven mutants displayed strikingly high basal activity compared to wild-type MEK. Overexpression of the MEK variants in HEK293T cells resulted in an increase in mitogen-activated protein (MAP) kinase phosphorylation, a finding consistent with the elevated basal activity of these constructs. Further, treatment with PD 184352 failed to inhibit Leu115Pro-stimulated MAP kinase activation in HEK293T cells, whereas all other variants had some reduction in phospho-MAP kinase levels. By using cyclic AMP-dependent protein kinase (1CDK) as a template, an MEK homology model was generated, with five of the seven identified residues clustered together, forming a potential hydrophobic binding pocket for PD 184352. Additionally, the model allowed identification of other potential residues that would interact with the inhibitor. Directed mutation of these residues supported this region's involvement with inhibitor binding.


2015 ◽  
Vol 16 (12) ◽  
pp. 12345-12359 ◽  
Author(s):  
Yuan Zhou ◽  
Yongzheng He ◽  
Richa Sharma ◽  
Wen Xing ◽  
Selina Estwick ◽  
...  

2010 ◽  
Vol 8 (4) ◽  
pp. 497-503
Author(s):  
Sreemathy Ramaswamy ◽  
Ivana Yen ◽  
Steve Sideris ◽  
Shiva Malek ◽  
Christopher E. Heise

2017 ◽  
Vol 114 (14) ◽  
pp. 3684-3689 ◽  
Author(s):  
Guang Li ◽  
Xian Liu ◽  
Chaofan Xing ◽  
Huayang Zhang ◽  
Sebastian M. Shimeld ◽  
...  

Many bilaterally symmetrical animals develop genetically programmed left–right asymmetries. In vertebrates, this process is under the control of Nodal signaling, which is restricted to the left side by Nodal antagonists Cerberus and Lefty. Amphioxus, the earliest diverging chordate lineage, has profound left–right asymmetry as a larva. We show that Cerberus, Nodal, Lefty, and their target transcription factor Pitx are sequentially activated in amphioxus embryos. We then address their function by transcription activator-like effector nucleases (TALEN)-based knockout and heat-shock promoter (HSP)-driven overexpression. Knockout of Cerberus leads to ectopic right-sided expression of Nodal, Lefty, and Pitx, whereas overexpression of Cerberus represses their left-sided expression. Overexpression of Nodal in turn represses Cerberus and activates Lefty and Pitx ectopically on the right side. We also show Lefty represses Nodal, whereas Pitx activates Nodal. These data combine in a model in which Cerberus determines whether the left-sided gene expression cassette is activated or repressed. These regulatory steps are essential for normal left–right asymmetry to develop, as when they are disrupted embryos may instead form two phenotypic left sides or two phenotypic right sides. Our study shows the regulatory cassette controlling left–right asymmetry was in place in the ancestor of amphioxus and vertebrates. This includes the Nodal inhibitors Cerberus and Lefty, both of which operate in feedback loops with Nodal and combine to establish asymmetric Pitx expression. Cerberus and Lefty are missing from most invertebrate lineages, marking this mechanism as an innovation in the lineage leading to modern chordates.


2007 ◽  
Vol 292 (5) ◽  
pp. F1471-F1478 ◽  
Author(s):  
Sung Il Kim ◽  
Joon Hyeok Kwak ◽  
Mareena Zachariah ◽  
Yanjuan He ◽  
Lin Wang ◽  
...  

We have previously demonstrated that transforming growth factor-β1 (TGF-β1) rapidly activates the mitogen-activated protein kinase kinase 3 (MKK3)-p38 MAPK signaling cascade, leading to the induction of type I collagen synthesis in mouse glomerular mesangial cells (Wang L, Ma R, Flavell RA, Choi ME. J Biol Chem 277: 47257–47262, 2002). In the present study, we investigated the functional role of upstream TGF-β-activated kinase 1 (TAK1) and TAK1-binding protein 1 (TAB1) in the TGF-β1 signaling cascade. Rapid activation of endogenous TAK1 activity by TGF-β1 was observed in mouse mesangial cells. Transient overexpression of TAK1 with TAB1 enhanced the activation of MKK3 and p38 MAPK with or without TGF-β1 stimulation, whereas a dominant-negative mutant of TAK1 (TAK1DN) suppressed TGF-β1-induced activation of MKK3 and p38 MAPK. Moreover, constitutive expression of TAK1DN reduced steady-state protein levels of MKK3 and p38 MAPK as well as MKK3 phosphorylation. Increased p38α MAPK activity by ectopic expression of either TAB1 or wild-type p38α MAPK resulted in enhanced TGF-β1-induced type I collagen expression. In contrast, constitutive expression of TAK1DN inhibited collagen induction. Taken together, our data indicate that TAK1 and TAB1 play a pivotal role as upstream signal transducers activating the MKK3-p38 MAPK signaling cascade that leads to the induction of type I collagen expression by TGF-β1. In addition, our findings also suggest that TAK1 has a novel function in regulation of the steady-state protein levels of MKK3 and p38 MAPK.


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