scholarly journals Mitogen-Activated Protein Kinase Phosphatases (MKPs) in Fungal Signaling: Conservation, Function, and Regulation

2019 ◽  
Vol 20 (7) ◽  
pp. 1709 ◽  
Author(s):  
Gema González-Rubio ◽  
Teresa Fernández-Acero ◽  
Humberto Martín ◽  
María Molina
Keyword(s):  
Rna Binding ◽  
Rna Binding Proteins ◽  
Specific Interaction ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Cell Physiology ◽  
Dual Specificity ◽  
Mitogen Activated Protein ◽  
Activation Mechanisms ◽  
Dual Specificity Phosphatases

Mitogen-activated protein kinases (MAPKs) are key mediators of signaling in fungi, participating in the response to diverse stresses and in developmental processes. Since the precise regulation of MAPKs is fundamental for cell physiology, fungi bear dual specificity phosphatases (DUSPs) that act as MAP kinase phosphatases (MKPs). Whereas fungal MKPs share characteristic domains of this phosphatase subfamily, they also have specific interaction motifs and particular activation mechanisms, which, for example, allow some yeast MKPs, such as Saccharomyces cerevisiae Sdp1, to couple oxidative stress with substrate recognition. Model yeasts show that MKPs play a key role in the modulation of MAPK signaling flow. Mutants affected in S. cerevisiae Msg5 or in Schizosaccharomyces pombe Pmp1 display MAPK hyperactivation and specific phenotypes. MKPs from virulent fungi, such as Candida albicans Cpp1, Fusarium graminearum Msg5, and Pyricularia oryzae Pmp1, are relevant for pathogenicity. Apart from transcriptional regulation, MKPs can be post-transcriptionally regulated by RNA-binding proteins such as Rnc1, which stabilizes the S. pombe PMP1 mRNA. P. oryzae Pmp1 activity and S. cerevisiae Msg5 stability are regulated by phosphorylation and ubiquitination, respectively. Therefore, fungi offer a platform to gain insight into the regulatory mechanisms that control MKPs.

scholarly journals Structure of human dual-specificity phosphatase 7, a potential cancer drug target

2015 ◽  
Vol 71 (6) ◽  
pp. 650-656 ◽  
Author(s):  
George T. Lountos ◽  
Brian P. Austin ◽  
Joseph E. Tropea ◽  
David S. Waugh
Keyword(s):  
Catalytic Domain ◽  
Three Dimensional ◽  
Mitogen Activated Protein Kinase ◽  
Cancer Drug ◽  
Dual Specificity Phosphatase ◽  
Dual Specificity ◽  
Starting Point ◽  
Mitogen Activated Protein ◽  
Dual Specificity Phosphatases

Human dual-specificity phosphatase 7 (DUSP7/Pyst2) is a 320-residue protein that belongs to the mitogen-activated protein kinase phosphatase (MKP) subfamily of dual-specificity phosphatases. Although its precise biological function is still not fully understood, previous reports have demonstrated that DUSP7 is overexpressed in myeloid leukemia and other malignancies. Therefore, there is interest in developing DUSP7 inhibitors as potential therapeutic agents, especially for cancer. Here, the purification, crystallization and structure determination of the catalytic domain of DUSP7 (Ser141–Ser289/C232S) at 1.67 Å resolution are reported. The structure described here provides a starting point for structure-assisted inhibitor-design efforts and adds to the growing knowledge base of three-dimensional structures of the dual-specificity phosphatase family.

scholarly journals Chirality-Dependent Anti-Inflammatory Effect of Glutathione after Spinal Cord Injury in an Animal Model

2021 ◽  
Vol 14 (8) ◽  
pp. 792
Author(s):  
Seong-Jun Kim ◽  
Wan-Kyu Ko ◽  
Gong-Ho Han ◽  
Daye Lee ◽  
Yuhan Lee ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Therapeutic Potential ◽  
Specific Interaction ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Secondary Damage ◽  
Cord Injury ◽  
Mitogen Activated Protein ◽  
Pro Inflammatory Cytokines

Neuroinflammation forms a glial scar following a spinal cord injury (SCI). The injured axon cannot regenerate across the scar, suggesting permanent paraplegia. Molecular chirality can show an entirely different bio-function by means of chiral-specific interaction. In this study, we report that d-chiral glutathione (D-GSH) suppresses the inflammatory response after SCI and leads to axon regeneration of the injured spinal cord to a greater extent than l-chiral glutathione (L-GSH). After SCI, axon regrowth in D-GSH-treated rats was significantly increased compared with that in L-GSH-treated rats (*** p < 0.001). Secondary damage and motor function were significantly improved in D-GSH-treated rats compared with those outcomes in L-GSH-treated rats (** p < 0.01). Moreover, D-GSH significantly decreased pro-inflammatory cytokines and glial fibrillary acidic protein (GFAP) via inhibition of the mitogen-activated protein kinase (MAPK) signaling pathway compared with L-GSH (*** p < 0.001). In primary cultured macrophages, we found that D-GSH undergoes more intracellular interaction with activated macrophages than L-GSH (*** p < 0.001). These findings reveal a potential new regenerative function of chiral GSH in SCI and suggest that chiral GSH has therapeutic potential as a treatment of other diseases.

scholarly journals JCPyV-Induced MAPK Signaling Activates Transcription Factors during Infection

2019 ◽  
Vol 20 (19) ◽  
pp. 4779 ◽  
Author(s):  
Jeanne K. DuShane ◽  
Colleen L. Mayberry ◽  
Michael P. Wilczek ◽  
Sarah L. Nichols ◽  
Melissa S. Maginnis
Keyword(s):  
Transcription Factors ◽  
Mapk Signaling ◽  
Mapk Cascade ◽  
Mitogen Activated Protein Kinase ◽  
Erk Pathway ◽  
Downstream Signaling ◽  
Dual Specificity ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Underlying Mechanisms

JC polyomavirus (JCPyV), a ubiquitous human pathogen, is the etiological agent of the fatal neurodegenerative disease progressive multifocal leukoencephalopathy (PML). Like most viruses, JCPyV infection requires the activation of host-cell signaling pathways in order to promote viral replication processes. Previous works have established the necessity of the extracellular signal-regulated kinase (ERK), the terminal core kinase of the mitogen-activated protein kinase (MAPK) cascade (MAPK-ERK) for facilitating transcription of the JCPyV genome. However, the underlying mechanisms by which the MAPK-ERK pathway becomes activated and induces viral transcription are poorly understood. Treatment of cells with siRNAs specific for Raf and MAP kinase kinase (MEK) targets proteins in the MAPK-ERK cascade, significantly reducing JCPyV infection. MEK, the dual-specificity kinase responsible for the phosphorylation of ERK, is phosphorylated at times congruent with early events in the virus infectious cycle. Moreover, a MAPK-specific signaling array revealed that transcription factors downstream of the MAPK cascade, including cMyc and SMAD4, are upregulated within infected cells. Confocal microscopy analysis demonstrated that cMyc and SMAD4 shuttle to the nucleus during infection, and nuclear localization is reduced when ERK is inhibited. These findings suggest that JCPyV induction of the MAPK-ERK pathway is mediated by Raf and MEK and leads to the activation of downstream transcription factors during infection. This study further defines the role of the MAPK cascade during JCPyV infection and the downstream signaling consequences, illuminating kinases as potential therapeutic targets for viral infection.

MKP-2: out of the DUSP-bin and back into the limelight

2012 ◽  
Vol 40 (1) ◽  
pp. 235-239 ◽  
Author(s):  
Ahmed Lawan ◽  
Emma Torrance ◽  
Sameer Al-Harthi ◽  
Muhannad Shweash ◽  
Sulaiman Alnasser ◽  
...  
Keyword(s):  
Cell Cycle Progression ◽  
Metabolic Disorders ◽  
Mitogen Activated Protein Kinase ◽  
Cycle Progression ◽  
Extracellular Signal Regulated Kinase ◽  
Dual Specificity ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Dual Specificity Phosphatases

The MKPs (mitogen-activated protein kinase phosphatases) are a family of at least ten DUSPs (dual-specificity phosphatases) which function to terminate the activity of the MAPKs (mitogen-activated protein kinases). Several members have already been demonstrated to have distinct roles in immune function, cancer, fetal development and metabolic disorders. One DUSP of renewed interest is the inducible nuclear phosphatase MKP-2, which dephosphorylates both ERK (extracellular-signal-regulated kinase) and JNK (c-Jun N-terminal kinase) in vitro. Recently, the understanding of MKP-2 function has been advanced due to the development of mouse knockout models, which has resulted in the discovery of novel roles for MKP-2 in the regulation of sepsis, infection and cell-cycle progression that are distinct from those of other DUSPs. However, many functions for MKP-2 still await to be characterized.

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.

Dual-specificity phosphatases: critical regulators with diverse cellular targets

2009 ◽  
Vol 418 (3) ◽  
pp. 475-489 ◽  
Author(s):  
Kate I. Patterson ◽  
Tilman Brummer ◽  
Philippa M. O'brien ◽  
Roger J. Daly
Keyword(s):  
Protein Kinase ◽  
Sequence Similarity ◽  
Mitogen Activated Protein Kinase ◽  
Cellular Targets ◽  
Dual Specificity ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Dual Specificity Phosphatases ◽  
The One ◽  
And Function

DUSPs (dual-specificity phosphatases) are a heterogeneous group of protein phosphatases that can dephosphorylate both phosphotyrosine and phosphoserine/phosphothreonine residues within the one substrate. DUSPs have been implicated as major modulators of critical signalling pathways that are dysregulated in various diseases. DUSPs can be divided into six subgroups on the basis of sequence similarity that include slingshots, PRLs (phosphatases of regenerating liver), Cdc14 phosphatases (Cdc is cell division cycle), PTENs (phosphatase and tensin homologues deleted on chromosome 10), myotubularins, MKPs (mitogen-activated protein kinase phosphatases) and atypical DUSPs. Of these subgroups, a great deal of research has focused on the characterization of the MKPs. As their name suggests, MKPs dephosphorylate MAPK (mitogen-activated protein kinase) proteins ERK (extracellular-signal-regulated kinase), JNK (c-Jun N-terminal kinase) and p38 with specificity distinct from that of individual MKP proteins. Atypical DUSPs are mostly of low-molecular-mass and lack the N-terminal CH2 (Cdc25 homology 2) domain common to MKPs. The discovery of most atypical DUSPs has occurred in the last 6 years, which has initiated a large amount of interest in their role and regulation. In the past, atypical DUSPs have generally been grouped together with the MKPs and characterized for their role in MAPK signalling cascades. Indeed, some have been shown to dephosphorylate MAPKs. The current literature hints at the potential of the atypical DUSPs as important signalling regulators, but is crowded with conflicting reports. The present review provides an overview of the DUSP family before focusing on atypical DUSPs, emerging as a group of proteins with vastly diverse substrate specificity and function.

scholarly journals Dual-Specificity Phosphatase Regulation in Neurons and Glial Cells

2019 ◽  
Vol 20 (8) ◽  
pp. 1999 ◽  
Author(s):  
Pérez-Sen ◽  
Queipo ◽  
Gil-Redondo ◽  
Ortega ◽  
Gómez-Villafuertes ◽  
...  
Keyword(s):  
Map Kinases ◽  
Protein Phosphatases ◽  
Mapk Signaling ◽  
Protein Stabilization ◽  
Mitogen Activated Protein Kinase ◽  
Brain Diseases ◽  
General Terms ◽  
Dual Specificity ◽  
Mitogen Activated Protein ◽  
Specificity Protein

Dual-specificity protein phosphatases comprise a protein phosphatase subfamily with selectivity towards mitogen-activated protein (MAP) kinases, also named MKPs, or mitogen-activated protein kinase (MAPK) phosphatases. As powerful regulators of the intensity and duration of MAPK signaling, a relevant role is envisioned for dual-specificity protein phosphatases (DUSPs) in the regulation of biological processes in the nervous system, such as differentiation, synaptic plasticity, and survival. Important neural mediators include nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) that contribute to DUSP transcriptional induction and post-translational mechanisms of DUSP protein stabilization to maintain neuronal survival and differentiation. Potent DUSP gene inducers also include cannabinoids, which preserve DUSP activity in inflammatory conditions. Additionally, nucleotides activating P2X7 and P2Y13 nucleotide receptors behave as novel players in the regulation of DUSP function. They increase cell survival in stressful conditions, regulating DUSP protein turnover and inducing DUSP gene expression. In general terms, in the context of neural cells exposed to damaging conditions, the recovery of DUSP activity is neuroprotective and counteracts pro-apoptotic over-activation of p38 and JNK. In addition, remarkable changes in DUSP function take place during the onset of neuropathologies. The restoration of proper DUSP levels and recovery of MAPK homeostasis underlie the therapeutic effect, indicating that DUSPs can be relevant targets for brain diseases.

scholarly journals RNA-Binding Protein Rnc1 Regulates Cell Length at Division and Acute Stress Response in Fission Yeast through Negative Feedback Modulation of the Stress-Activated Mitogen-Activated Protein Kinase Pathway

mBio ◽  
2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Francisco Prieto-Ruiz ◽  
Jero Vicente-Soler ◽  
Alejandro Franco ◽  
Elisa Gómez-Gil ◽  
Marta Sánchez-Marinas ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Fission Yeast ◽  
Binding Proteins ◽  
Rna Binding ◽  
Acute Stress ◽  
Rna Binding Proteins ◽  
Cell Length ◽  
Mitogen Activated Protein Kinase ◽  
Content Type ◽  
Mitogen Activated Protein

ABSTRACT RNA-binding proteins (RBPs) play a major role during control of mRNA localization, stability, and translation and are central to most cellular processes. In the fission yeast Schizosaccharomyces pombe, the multiple K homology (KH) domain RBP Rnc1 downregulates the activity of the cell integrity pathway (CIP) via stabilization of pmp1+ mRNA, which encodes the Pmp1 phosphatase that inactivates Pmk1, the mitogen-activated protein kinase (MAPK) component of this signaling cascade. However, Rnc1 likely regulates the half-life/stability of additional mRNAs. We show that Rnc1 downregulates the activity of Sty1, the MAPK of the stress-activated MAPK pathway (SAPK), during control of cell length at division and recovery in response to acute stress. Importantly, this control strictly depends on Rnc1’s ability to bind mRNAs encoding activators (Wak1 MAPKKK, Wis1 MAPKK) and downregulators (Atf1 transcription factor, Pyp1 and Pyp2 phosphatases) of Sty1 phosphorylation through its KH domains. Moreover, Sty1 is responsible for Rnc1 phosphorylation in vivo at multiple phosphosites during growth and stress, and these modifications trigger Rnc1 for proper binding and destabilization of the above mRNA targets. Phosphorylation by Sty1 prompts Rnc1-dependent mRNA destabilization to negatively control SAPK signaling, thus revealing an additional feedback mechanism that allows precise tuning of MAPK activity during unperturbed cell growth and stress. IMPORTANCE Control of mRNA localization, stability, turnover, and translation by RNA-binding proteins (RBPs) influences essential processes in all eukaryotes, including signaling by mitogen-activated protein kinase (MAPK) pathways. We describe that in the fission yeast Schizosaccharomyces pombe the RBP Rnc1 negatively regulates cell length at division during unperturbed growth and recovery after acute stress by reducing the activity of the MAPK Sty1, which regulates cell growth and differentiation during environmental cues. This mechanism relies on Rnc1 binding to specific mRNAs encoding both enhancers and negative regulators of Sty1 activity. Remarkably, multiple phosphorylation of Rnc1 by Sty1 favors RBP binding and destabilization of the above mRNAs. Thus, posttranscriptional modulation of MAP kinase signaling by RNA-binding proteins emerges as a major regulatory mechanism that dictates the growth cycle and cellular adaptation in response to the changing environment in eukaryotic organisms.

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