Molecular mechanisms of phosphorylation-regulated TTP (tristetraprolin) action and screening for further TTP-interacting proteins

2010 ◽  
Vol 38 (6) ◽  
pp. 1632-1637 ◽  
Author(s):  
Christopher Tiedje ◽  
Alexey Kotlyarov ◽  
Matthias Gaestel
Keyword(s):  
Protein Kinase ◽  
Mrna Stability ◽  
Molecular Mechanisms ◽  
Rna Binding ◽  
Hybrid Approach ◽  
Mitogen Activated Protein Kinase ◽  
Interacting Proteins ◽  
Interaction Partners ◽  
Mitogen Activated Protein ◽  
Dependent Interaction

TTP (tristetraprolin) is an RNA-binding protein which regulates mRNA stability or translation or both. The molecular mechanisms which are responsible and which discriminate between regulation of mRNA stability and translation are not completely understood so far, but are clearly dependent on p38 MAPK (mitogen-activated protein kinase)/MK (MAPK-activated protein kinase) 2/3-mediated phosphorylation of TTP. To learn more about these mechanisms, phosphorylation-dependent TTP-interacting proteins could be of great interest. Many interacting partners, which belong to the mRNA-processing and -regulating machinery, have been identified by hypothesis-driven co-immunoprecipitation and in the classical Y2H (yeast two-hybrid) approach, where TTP was identified as prey, and are summarized in the present paper. However, because of transactivating properties of TTP, an unbiased Y2H approach using TTP as bait was hindered. Since novel methods for the identification of phosphorylation-dependent interaction partners and of interactors of full-length auto-activating proteins in eukaryotic systems have evolved in the last few years, these methods should be applied to screen for additional phosphorylation-dependent interaction partners of TTP and could lead towards a complete understanding of TTP function at the molecular level.

scholarly journals Role of the RNA-binding Protein Nrd1 and Pmk1 Mitogen-activated Protein Kinase in the Regulation of Myosin mRNA Stability in Fission Yeast

2009 ◽  
Vol 20 (9) ◽  
pp. 2473-2485 ◽  
Author(s):  
Ryosuke Satoh ◽  
Takahiro Morita ◽  
Hirofumi Takada ◽  
Ayako Kita ◽  
Shunji Ishiwata ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Fission Yeast ◽  
Mrna Stability ◽  
Rna Binding ◽  
Binding Protein ◽  
Myosin Ii ◽  
Rna Binding Protein ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Mitogen Activated Protein

Myosin II is an essential component of the actomyosin contractile ring and plays a crucial role in cytokinesis by generating the forces necessary for contraction of the actomyosin ring. Cdc4 is an essential myosin II light chain in fission yeast and is required for cytokinesis. In various eukaryotes, the phosphorylation of myosin is well documented as a primary means of activating myosin II, but little is known about the regulatory mechanisms of Cdc4. Here, we isolated Nrd1, an RNA-binding protein with RNA-recognition motifs, as a multicopy suppressor of cdc4 mutants. Notably, we demonstrated that Nrd1 binds and stabilizes Cdc4 mRNA, thereby suppressing the cytokinesis defects of the cdc4 mutants. Importantly, Pmk1 mitogen-activated protein kinase (MAPK) directly phosphorylates Nrd1, thereby negatively regulating the binding activity of Nrd1 to Cdc4 mRNA. Consistently, the inactivation of Pmk1 MAPK signaling, as well as Nrd1 overexpression, stabilized the Cdc4 mRNA level, thereby suppressing the cytokinesis defects associated with the cdc4 mutants. In addition, we demonstrated the cell cycle–dependent regulation of Pmk1/Nrd1 signaling. Together, our results indicate that Nrd1 plays a role in the regulation of Cdc4 mRNA stability; moreover, our study is the first to demonstrate the posttranscriptional regulation of myosin expression by MAPK signaling.

Control of mRNA decay by phosphorylation of tristetraprolin

2008 ◽  
Vol 36 (3) ◽  
pp. 491-496 ◽  
Author(s):  
Heike Sandler ◽  
Georg Stoecklin
Keyword(s):  
Protein Kinase ◽  
Untranslated Region ◽  
Rna Binding ◽  
Rna Binding Protein ◽  
Mitogen Activated Protein Kinase ◽  
Interacting Proteins ◽  
Mitogen Activated Protein ◽  
Kinase Cascade ◽  
Transient Stabilization ◽  
Cytokine Mrnas

TTP (tristetraprolin) is an RNA-binding protein that suppresses inflammation by accelerating the degradation of cytokine mRNAs. TTP binds to an AU-rich element in the 3′-untranslated region of its target mRNAs. In macrophages, the induction of cytokine expression requires activation of the p38-MAPK (mitogen-activated protein kinase)–MK2 [MAPKAP (MAPK-activated protein) kinase-2] kinase cascade. MK2 directly phosphorylates TTP and thereby contributes to transient stabilization of cytokine mRNAs. In the present review, we address the target specificity of TTP, summarize TTP-interacting proteins and discuss how phosphorylation regulates the activity, localization and stability of TTP.

scholarly journals The TGFβ-induced phosphorylation and activation of p38 mitogen-activated protein kinase is mediated by MAP3K4 and MAP3K10 but not TAK1

Open Biology ◽  
2013 ◽  
Vol 3 (6) ◽  
pp. 130067 ◽  
Author(s):  
Gopal P. Sapkota
Keyword(s):  
Protein Kinase ◽  
P38 Mapk ◽  
Transforming Growth Factor Beta ◽  
Molecular Mechanisms ◽  
Epithelial To Mesenchymal Transition ◽  
Transforming Growth Factor ◽  
Mitogen Activated Protein Kinase ◽  
Mapk Phosphorylation ◽  
Mesenchymal Transition ◽  
Mitogen Activated Protein

The signalling pathways downstream of the transforming growth factor beta (TGFβ) family of cytokines play critical roles in all aspects of cellular homeostasis. The phosphorylation and activation of p38 mitogen-activated protein kinase (MAPK) has been implicated in TGFβ-induced epithelial-to-mesenchymal transition and apoptosis. The precise molecular mechanisms by which TGFβ cytokines induce the phosphorylation and activation of p38 MAPK are unclear. In this study, I demonstrate that TGFβ-activated kinase 1 (TAK1/MAP3K7) does not play a role in the TGFβ-induced phosphorylation and activation of p38 MAPK in MEFs and HaCaT keratinocytes. Instead, RNAi -mediated depletion of MAP3K4 and MAP3K10 results in the inhibition of the TGFβ-induced p38 MAPK phosphorylation. Furthermore, the depletion of MAP3K10 from cells homozygously knocked-in with a catalytically inactive mutant of MAP3K4 completely abolishes the TGFβ-induced phosphorylation of p38 MAPK, implying that among MAP3Ks, MAP3K4 and MAP3K10 are sufficient for mediating the TGFβ-induced activation of p38 MAPK.

scholarly journals Role of Reactive Oxygen Species in Cancer Progression: Molecular Mechanisms and Recent Advancements

Biomolecules ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 735 ◽  
Author(s):  
Vaishali Aggarwal ◽  
Hardeep Tuli ◽  
Ayşegül Varol ◽  
Falak Thakral ◽  
Mukerrem Yerer ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Protein Kinase ◽  
Cancer Cell ◽  
Cancer Progression ◽  
Molecular Mechanisms ◽  
Reactive Oxygen ◽  
Mitogen Activated Protein Kinase ◽  
Oxygen Species ◽  
Mitogen Activated Protein ◽  
High Concentrations

Reactive oxygen species (ROS) play a pivotal role in biological processes and continuous ROS production in normal cells is controlled by the appropriate regulation between the silver lining of low and high ROS concentration mediated effects. Interestingly, ROS also dynamically influences the tumor microenvironment and is known to initiate cancer angiogenesis, metastasis, and survival at different concentrations. At moderate concentration, ROS activates the cancer cell survival signaling cascade involving mitogen-activated protein kinase/extracellular signal-regulated protein kinases 1/2 (MAPK/ERK1/2), p38, c-Jun N-terminal kinase (JNK), and phosphoinositide-3-kinase/ protein kinase B (PI3K/Akt), which in turn activate the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), matrix metalloproteinases (MMPs), and vascular endothelial growth factor (VEGF). At high concentrations, ROS can cause cancer cell apoptosis. Hence, it critically depends upon the ROS levels, to either augment tumorigenesis or lead to apoptosis. The major issue is targeting the dual actions of ROS effectively with respect to the concentration bias, which needs to be monitored carefully to impede tumor angiogenesis and metastasis for ROS to serve as potential therapeutic targets exogenously/endogenously. Overall, additional research is required to comprehend the potential of ROS as an effective anti-tumor modality and therapeutic target for treating malignancies.

scholarly journals Saccharomyces cerevisiae and Caffeine Implications on the Eukaryotic Cell

Nutrients ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2440
Author(s):  
Lavinia Liliana Ruta ◽  
Ileana Cornelia Farcasanu
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Molecular Mechanisms ◽  
Eukaryotic Cell ◽  
Pleiotropic Effect ◽  
Mitogen Activated Protein Kinase ◽  
Active Principle ◽  
Cell Integrity ◽  
Tor Signaling ◽  
Mitogen Activated Protein

Caffeine–a methylxanthine analogue of the purine bases adenine and guanine–is by far the most consumed neuro-stimulant, being the active principle of widely consumed beverages such as coffee, tea, hot chocolate, and cola. While the best-known action of caffeine is to prevent sleepiness by blocking the adenosine receptors, caffeine exerts a pleiotropic effect on cells, which lead to the activation or inhibition of various cell integrity pathways. The aim of this review is to present the main studies set to investigate the effects of caffeine on cells using the model eukaryotic microorganism Saccharomyces cerevisiae, highlighting the caffeine synergy with external cell stressors, such as irradiation or exposure to various chemical hazards, including cigarette smoke or chemical carcinogens. The review also focuses on the importance of caffeine-related yeast phenotypes used to resolve molecular mechanisms involved in cell signaling through conserved pathways, such as target of rapamycin (TOR) signaling, Pkc1-Mpk1 mitogen activated protein kinase (MAPK) cascade, or Ras/cAMP protein kinase A (PKA) pathway.

scholarly journals Phosphorylation of the ARE-binding protein DAZAP1 by ERK2 induces its dissociation from DAZ

2006 ◽  
Vol 399 (2) ◽  
pp. 265-273 ◽  
Author(s):  
Simon Morton ◽  
Huei-Ting Yang ◽  
Ntsane Moleleki ◽  
David G. Campbell ◽  
Philip Cohen ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Rna Binding ◽  
Binding Protein ◽  
Mitogen Activated Protein Kinase ◽  
Raw 264.7 ◽  
Raw 264.7 Macrophages ◽  
Hek 293 ◽  
Extracellular Signal ◽  
Mitogen Activated Protein

A protein in RAW 264.7 macrophages, which became phosphorylated in response to LPS (lipopolysaccharide), was identified as the RNA-binding protein called DAZAP1 [DAZ (deleted in azoospermia)-associated protein 1]. The phosphorylation of this protein was prevented by specific inhibition of MKK1 [MAPK (mitogen-activated protein kinase) kinase 1], indicating that it was phosphorylated via the classical MAPK cascade. Further experiments showed that DAZAP1 was phosphorylated stoichiometrically in vitro by ERK2 (extracellular-signal-regulated protein kinase 2) at two Thr-Pro sequences (Thr269 and Thr315), and that both sites became phosphorylated in HEK-293 (human embryonic kidney 293) cells in response to PMA or EGF (epidermal growth factor), or RAW 264.7 macrophages in response to LPS. Phosphorylation induced by each stimulus was prevented by two structurally distinct inhibitors of MKK1 (PD184352 and U0126), demonstrating that DAZAP1 is a physiological substrate for ERK1/ERK2. The mutation of Thr269 and Thr315 to aspartate or the phosphorylation of these residues caused DAZAP1 to dissociate from its binding partner DAZ. DAZ interacts with PABP [poly(A)-binding protein] and thereby stimulates the translation of mRNAs containing short poly(A) tails [Collier, Gorgoni, Loveridge, Cooke and Gray (2005) EMBO J. 24, 2656–2666]. In the present study we have shown that DAZ cannot bind simultaneously to DAZAP1 and PABP, and suggest that the phosphorylation-induced dissociation of DAZ and DAZAP1 may allow the former to stimulate translation by interacting with PABP.

scholarly journals Regulation of Cyclooxygenase 2 mRNA Stability by the Mitogen-Activated Protein Kinase p38 Signaling Cascade

2000 ◽  
Vol 20 (12) ◽  
pp. 4265-4274 ◽  
Author(s):  
Marina Lasa ◽  
Kamal R. Mahtani ◽  
Andrew Finch ◽  
Gary Brewer ◽  
Jeremy Saklatvala ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Mrna Stability ◽  
Active Form ◽  
Cyclooxygenase 2 ◽  
Dominant Negative ◽  
Mitogen Activated Protein Kinase ◽  
Signaling Cascade ◽  
Mitogen Activated Protein ◽  
Cox 2 ◽  
Constitutively Active

ABSTRACT A tetracycline-regulated reporter system was used to investigate the regulation of cyclooxygenase 2 (Cox-2) mRNA stability by the mitogen-activated protein kinase (MAPK) p38 signaling cascade. The stable β-globin mRNA was rendered unstable by insertion of the 2,500-nucleotide Cox-2 3′ untranslated region (3′ UTR). The chimeric transcript was stabilized by a constitutively active form of MAPK kinase 6, an activator of p38. This stabilization was blocked by SB203580, an inhibitor of p38, and by two different dominant negative forms of MAPK-activated protein kinase 2 (MAPKAPK-2), a kinase lying downstream of p38. Constitutively active MAPKAPK-2 was also able to stabilize chimeric β-globin–Cox-2 transcripts. The MAPKAPK-2 substrate hsp27 may be involved in stabilization, as β-globin–Cox-2 transcripts were partially stabilized by phosphomimetic mutant forms of hsp27. A short (123-nucleotide) fragment of the Cox-2 3′ UTR was necessary and sufficient for the regulation of mRNA stability by the p38 cascade and interacted with a HeLa protein immunologically related to AU-rich element/poly(U) binding factor 1.

scholarly journals CircRNA LRIG3 knockdown inhibits hepatocellular carcinoma progression by regulating miR-223-3p and MAPK/ERK pathway

2021 ◽  
Author(s):  
Hui Sun ◽  
Junwei Zhai ◽  
Li Zhang ◽  
Yingnan Chen
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Proliferation ◽  
Protein Kinase ◽  
Molecular Mechanisms ◽  
Mitogen Activated Protein Kinase ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Erk Pathway ◽  
Mitogen Activated Protein ◽  
Hcc Cells

IntroductionEmerging evidence suggests that circular RNAs (circRNAs) play critical roles in tumorigenesis. However, the roles and molecular mechanisms of circRNA leucine-rich repeat immunoglobulin domain-containing protein 3 (circ_LRIG3) in hepatocellular carcinoma (HCC) has not been investigated.Material and methodsThe expression levels of circ_LRIG3, miR-223-3p, and mitogen-activated protein kinase kinase 6 (MAP2K6) were determined by qRT-PCR. Flow cytometry was applied to determine the cell cycle distribution and apoptosis. Cell proliferation, migration and invasion were assessed by MTT, colony formation, and transwell assays. Western blot assay was employed to measure the protein levels of the snail, E-cadherin, MAP2K6, mitogen-activated protein kinase (MAPK), phospho-MAPK (p-MAPK), extracellular signal-regulated kinases (ERKs), and phospho-ERKs (p- ERKs). The relationship between miR-223-3p and circ_LRIG3 or MAP2K6 was predicted by bioinformatics tools and verified by dual-luciferase reporter assay. A xenograft tumor model was established to confirm the functions of circ_LRIG3 in vivo.ResultsCirc_LRIG3 and MAP2K6 expression were enhanced while miR-223-3p abundance was reduced in HCC tissues and cells. Knockdown of circ_LRIG3 inhibited cell proliferation, metastasis, and increasing apoptosis. MiR-223-3p was a target of circ_LRIG3, and its downregulation reversed the inhibitory effect of circ_LRIG3 knockdown on the progression of HCC cells. Moreover, MAP2K6 could bind to miR-223-3p, and MAP2K6 upregulation also abolished the suppressive impact of circ_LRIG3 interference on progression of HCC cells. Additionally, the silence of circ_LRIG3 suppressed the activation of the MAPK/ERK pathway and tumor growth by upregulating miR-223-3p and downregulating MAP2K6.ConclusionsCirc_LRIG3 knockdown inhibited HCC progression through regulating miR-223-3p/MAP2K6 axis and inactivating MAPK/ERK pathway.

scholarly journals Ras-Related C3 Botulinum Toxin Substrate 1 Combining With the Mixed Lineage Kinase 3- Mitogen-Activated Protein Kinase 7- c-Jun N-Terminal Kinase Signaling Module Accelerates Diabetic Nephropathy

2021 ◽  
Vol 12 ◽  
Author(s):  
Changjiang Ying ◽  
Jiao Dai ◽  
Gaoxia Fan ◽  
Zhongyuan Zhou ◽  
Tian Gan ◽  
...  
Keyword(s):  
Diabetic Nephropathy ◽  
Botulinum Toxin ◽  
Protein Kinase ◽  
Molecular Mechanisms ◽  
Caspase 3 ◽  
Mitogen Activated Protein Kinase ◽  
Jnk Signaling ◽  
Mixed Lineage Kinase ◽  
Mitogen Activated Protein ◽  
Mixed Lineage Kinase 3

Ras-related C3 botulinum toxin substrate 1 (RAC1) activation plays a vital role in diabetic nephropathy (DN), but the exact mechanism remains unclear. In this study, we attempted to elucidate the precise mechanism of how RAC1 aggravates DN through cellular and animal experiments. In this study, DN was induced in mice by intraperitoneal injection of streptozotocin (STZ, 150mg/kg), and the RAC1 inhibitor NSC23766 was administered by tail vein injection. Biochemical indicators, cell proliferation and apoptosis, and morphological changes in the kidney were detected. The expression of phosphorylated c-Jun N-terminal kinase (p-JNK), nuclear factor-κB (NF-κB), and cleaved caspase-3 and the interaction between RAC1 and the mixed lineage kinase 3 (MLK3)-mitogen-activated protein kinase 7 (MKK7)-JNK signaling module were determined. Furthermore, the colocalization and direct co-interaction of RAC1 and MLK3 were confirmed. Our results showed that RAC1 accelerates renal damage and increases the expression of p-JNK, NF-κB, and cleaved caspase-3. However, inhibition of RAC1 ameliorated DN by downregulating p-JNK, NF-κB, and cleaved caspase-3. Also, RAC1 promoted the assembly of MLK3-MKK7-JNK, and NSC23766 blocked the interaction between RAC1 and MLK3-MKK7-JNK and inhibited the assembly of the MLK3-MKK7-JNK signaling module. Furthermore, RAC1 was combined with MLK3 directly, but the RAC1 Y40C mutant inhibited the interaction between RAC1 and MLK3. We demonstrated that RAC1 combining with MLK3 activates the MLK3-MKK7-JNK signaling module, accelerating DN occurrence and development, and RAC1 Y40 is an important site for binding of RAC1 to MLK3. This study illustrates the cellular and molecular mechanisms of how RAC1 accelerates DN and provides evidence of DN-targeted therapy.

Activation of members of the mitogen-activated protein kinase family by glucose in endothelial cells

2000 ◽  
Vol 279 (4) ◽  
pp. E782-E790 ◽  
Author(s):  
Wenli Liu ◽  
Aaron Schoenkerman ◽  
William L. Lowe
Keyword(s):  
Endothelial Cells ◽  
Protein Kinase ◽  
Molecular Mechanisms ◽  
Normal Growth ◽  
Inhibitory Effect ◽  
Mitogen Activated Protein Kinase ◽  
P38 Kinase ◽  
Hexosamine Pathway ◽  
Mitogen Activated Protein ◽  
Effect Of Glucose

To better understand the molecular mechanisms for hyperglycemia-induced proatherogenic changes in endothelial cells, the effect of high glucose on activation of members of the mitogen-activated protein kinase (MAPK) family, including c-Jun NH2-terminal kinase (JNK), extracellular signal-regulated kinase (ERK)-1, -2, and -5, and p38 kinase, was examined in bovine pulmonary artery endothelial cells (PAEC). Glucose, fructose, and raffinose induced a concentration-dependent decrease in PAEC growth. Addition of 25 mM glucose, fructose, or raffinose to normal growth medium stimulated an approximately twofold increase in JNK1 activity that was maximal after 24 h, whereas only glucose markedly increased ERK5 activity. Neither ERK1/2 nor p38 kinase activity was increased by glucose, fructose, or raffinose. The antioxidant N-acetylcysteine partially abrogated the glucose-induced increase in ERK5 activity but had no effect on the increase in JNK1 activity. In contrast, azaserine, which prevents increased flux through the hexosamine pathway, decreased glucose-induced JNK1 activity but had no effect on fructose- or raffinose-induced JNK1 activity. Consistent with this finding, glucosamine stimulated a 2.4-fold increase in JNK1 activity and reproduced the inhibitory effect of glucose on PAEC growth. In summary, glucose activates different members of the MAPK family in PAEC via distinct mechanisms. Moreover, the correlation between the ability of different sugars to activate JNK1 and inhibit cell growth suggests that activation of this signaling pathway may contribute to the growth inhibitory effect of glucose in endothelial cells.

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