PTPIP51 crosslinks the NFκB signaling and the MAPK pathway in SKBR3 cells and provides a bypass mechanism for NFκB inhibition

2019 ◽  
Author(s):  
Eric Dietel ◽  
Alexander Brobeil ◽  
Claudia Tag ◽  
Stefan Gattenloehner ◽  
Monika Wimmer
Keyword(s):  
Breast Cancer ◽  
Cell Viability ◽  
Mapk Pathway ◽  
Tyrosine Phosphatase ◽  
Large Body ◽  
Therapy Resistance ◽  
Mapk Signaling ◽  
Scaffolding Protein ◽  
Hacat Cells ◽  
Interacting Protein

Abstract Background Previous studies of our group revealed an association of the scaffolding protein Protein Tyrosine Phosphatase Interacting Protein 51 (PTPIP51) with the NFκB signaling on the RelA and IκB level. The NFκB signaling plays a pivotal role in many different tumor entities. Especially HER2 amplified breast cancer cells frequently display activation of the NFκB signaling. Here, the NFκB signaling is linked to the initiation, progression, and the metastasis of the breast cancer. Furthermore, a large body of evidence associates the NFκB signaling with the development of therapy resistance. We aimed to clarify the effects of NFκB inhibition on the NFκB- and the MAPK-related interactome of PTPIP51 in HaCat cells and SKBR3 cells and their correlation with cell viability. Results Both NFκB signaling inhibitors, PDTC and IKK-16, reduced the cell viability of SKBR3 cells. IKK-16 selectively reduced the cell viability in SKBR3 cells at 5µM, while the viability of HaCat cells was not affected. PDTC impaired the cell viability of both cell lines and induced a formation of the Raf1/14-3-3/PTPIP51 complex in SKBR3 cells, indicating a shift of PTPIP51 into MAPK signaling. The MAPK-related interactome of PTPIP51 remained unaffected by IKK-16. Conclusion (1)The effectiveness and selectivity of NFκB inhibition in malignant and non-malignant signaling systems depends on the level of the targeted signaling molecule. (2) PTPIP51 might serve as the mediator between the NFκB signaling and the MAPK pathway in SKBR3 cells upon NFκB inhibition.

scholarly journals PTPIP51 crosslinks the NFκB signaling and the MAPK pathway in SKBR3 cells

2020 ◽  
Vol 6 (5) ◽  
pp. FSO463
Author(s):  
Eric Dietel ◽  
Alexander Brobeil ◽  
Claudia Tag ◽  
Stefan Gattenloehner ◽  
Monika Wimmer
Keyword(s):  
Breast Cancer ◽  
Cell Viability ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Mapk Pathway ◽  
Mapk Signaling ◽  
Hacat Cells

Aim: PTPIP51 interacts with NFκB signaling at the RelA and IκB level. NFκB signaling is linked to the initiation, progression and metastasis of breast cancer. Her2-amplified breast cancer cells frequently display activation of the NFκB signaling. We aimed to clarify the effects of NFκB inhibition on the NFκB- and MAPK-related interactome of PTPIP51 and cell viability in HaCat cells and SKBR3 cells. Results: IKK-16 selectively reduced cell viability in SKBR3 cells. PDTC induced a formation of the Raf1/14-3-3/PTPIP51 complex in SKBR3 cells, indicating a shift of PTPIP51 into MAPK signaling. Conclusion: IKK-16 selectively inhibits cell viability of SKBR3 cells. In addition, PTPIP51 might serve as the mediator between NFκB signaling and the MAPK pathway in SKBR3.

scholarly journals APPL1 mediates adiponectin-stimulated p38 MAPK activation by scaffolding the TAK1-MKK3-p38 MAPK pathway

2011 ◽  
Vol 300 (1) ◽  
pp. E103-E110 ◽  
Author(s):  
Xiaoban Xin ◽  
Lijun Zhou ◽  
Caleb M. Reyes ◽  
Feng Liu ◽  
Lily Q. Dong
Keyword(s):  
Protein Kinase ◽  
P38 Mapk ◽  
Mapk Pathway ◽  
Adaptor Protein ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Scaffolding Protein ◽  
Mapk Activation ◽  
P38 Mapk Pathway ◽  
Mitogen Activated Protein

The adaptor protein APPL1 mediates the stimulatory effect of adiponectin on p38 mitogen-activated protein kinase (MAPK) signaling, yet the underlying mechanism remains unclear. Here we show that, in C2C12 cells, overexpression or suppression of APPL1 enhanced or suppressed, respectively, adiponectin-stimulated p38 MAPK upstream kinase cascade, consisting of transforming growth factor-β-activated kinase 1 (TAK1) and mitogen-activated protein kinase kinase 3 (MKK3). In vitro affinity binding and coimmunoprecipitation experiments revealed that TAK1 and MKK3 bind to different regions of APPL1, suggesting that APPL1 functions as a scaffolding protein to facilitate adiponectin-stimulated p38 MAPK activation. Interestingly, suppressing APPL1 had no effect on TNFα-stimulated p38 MAPK phosphorylation in C2C12 myotubes, indicating that the stimulatory effect of APPL1 on p38 MAPK activation is selective. Taken together, our study demonstrated that the TAK1-MKK3 cascade mediates adiponectin signaling and uncovers a scaffolding role of APPL1 in regulating the TAK1-MKK3-p38 MAPK pathway, specifically in response to adiponectin stimulation.

scholarly journals Dihydrochalcone Derivative Induces Breast Cancer Cell Apoptosis via Intrinsic, Extrinsic, and ER Stress Pathways but Abolishes EGFR/MAPK Pathway

2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Wasitta Rachakhom ◽  
Patompong Khaw-on ◽  
Wilart Pompimon ◽  
Ratana Banjerdpongchai
Keyword(s):  
Breast Cancer ◽  
Er Stress ◽  
Cell Lines ◽  
Cell Apoptosis ◽  
Mapk Pathway ◽  
Annexin V ◽  
Mapk Signaling ◽  
Dependent Manner ◽  
Induced Apoptosis ◽  
Mcf 7

Dihydrochalcone derivatives are active compounds that have been purified from the Thai medicinal plant Cyathostemma argenteum. The objectives of this study were to investigate the effects of two dihydrochalcone derivatives on human breast cancer MDA-MB-231 and MCF-7 cell proliferation and to study the relevant mechanisms involved. The two dihydrochalcone derivatives are 4′,6′-dihydroxy-2′,4-dimethoxy-5′-(2″-hydroxybenzyl)dihydrochalcone (compound 1) and calomelanone (2′,6′-dihydroxy-4,4′-dimethoxydihydrochalcone, compound 2), both of which induced cytotoxicity toward both cell lines in a dose-dependent manner by using MTT assay. Treatment with both derivatives induced apoptosis as determined by annexin V-FITC/propidium iodide employing flow cytometry. The reduction of mitochondrial transmembrane potential (staining with 3,3′-dihexyloxacarbocyanine iodide, DiOC6, employing a flow cytometer) was established in the compound 1-treated cells. Compound 1 induced caspase-3, caspase-8, and caspase-9 activities in both cell lines, as has been determined by specific colorimetric substrates and a spectrophotometric microplate reader which indicated the involvement of both the extrinsic and intrinsic pathways. Calcium ion levels in mitochondrial and cytosolic compartments increased in compound 1-treated cells as detected by Rhod-2AM and Fluo-3AM intensity, respectively, indicating the involvement of the endoplasmic reticulum (ER) stress pathway. Compound 1 induced cell cycle arrest via enhanced atm and atr expressions and by upregulating proapoptotic proteins, namely, Bim, Bad, and tBid. Moreover, compound 1 significantly inhibited the EGFR/MAPK signaling pathway. In conclusion, compound 1 induced MDA-MB-231 and MCF-7 cell apoptosis via intrinsic, extrinsic, and ER stress pathways, whereas it ameliorated the EGFR/MAPK pathway in the MCF-7 cell line. Consequently, it is believed that compound 1 could be effectively developed for cancer treatments.

A structural model of a Ras-Raf signalosome

2020 ◽  
Author(s):  
Venkatesh P. Mysore ◽  
Zhi-Wei Zhou ◽  
Chiara Ambrogio ◽  
Lianbo Li ◽  
Jonas N. Kapp ◽  
...  
Keyword(s):  
Structural Model ◽  
Mapk Pathway ◽  
Large Body ◽  
Mapk Signaling ◽  
Effector Proteins ◽  
Ras Proteins ◽  
Starting Point ◽  
Galectin 3 ◽  
Dynamics Simulations ◽  
Composite Interfaces

AbstractThe protein K-Ras functions as a molecular switch in signaling pathways regulating cell growth. In the MAPK pathway, which is implicated in many cancers, multiple K-Ras proteins are thought to assemble at the cell membrane with Ras-effector proteins from the Raf family. Here we propose an atomistic structural model for such an assembly. Our starting point was an asymmetric, GTP-mediated K-Ras dimer model, which we generated using unbiased molecular dynamics simulations and verified with mutagenesis experiments. Adding further K-Ras monomers in a head-to-tail fashion led to a compact helical assembly, a model we validated using electron microscopy and cell-based experiments. This assembly stabilizes K-Ras in its active state and presents composite interfaces to facilitate Raf binding. Guided by existing experimental data, we then positioned C-Raf, the downstream kinase MEK1, and accessory proteins (Galectin-3 and 14-3-3σ) on the helical assembly. The resulting Ras-Raf signalosome model offers an explanation for a large body of data on MAPK signaling.

scholarly journals Extracellular Signal-Regulated Kinase 2 Interacts with and Is Negatively Regulated by the LIM-Only Protein FHL2 in Cardiomyocytes

2004 ◽  
Vol 24 (3) ◽  
pp. 1081-1095 ◽  
Author(s):  
Nicole H. Purcell ◽  
Dina Darwis ◽  
Orlando F. Bueno ◽  
Judith M. Müller ◽  
Roland Schüle ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Mapk Pathway ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Erk Signaling ◽  
Interacting Protein ◽  
Hypertrophic Response ◽  
Extracellular Signal ◽  
Mitogen Activated Protein

ABSTRACT The mitogen-activated protein kinase (MAPK) signaling pathway regulates diverse biologic functions including cell growth, differentiation, proliferation, and apoptosis. The extracellular signal-regulated kinases (ERKs) constitute one branch of the MAPK pathway that has been implicated in the regulation of cardiac differentiated growth, although the downstream mechanisms whereby ERK signaling affects this process are not well characterized. Here we performed a yeast two-hybrid screen with ERK2 bait and a cardiac cDNA library to identify novel proteins involved in regulating ERK signaling in cardiomyocytes. This screen identified the LIM-only factor FHL2 as an ERK interacting protein in both yeast and mammalian cells. In vivo, FHL2 and ERK2 colocalized in the cytoplasm at the level of the Z-line, and interestingly, FHL2 interacted more efficiently with the activated form of ERK2 than with the dephosphorylated form. ERK2 also interacted with FHL1 and FHL3 but not with the muscle LIM protein. Moreover, at least two LIM domains in FHL2 were required to mediate efficient interaction with ERK2. The interaction between ERK2 and FHL2 did not influence ERK1/2 activation, nor was FHL2 directly phosphorylated by ERK2. However, FHL2 inhibited the ability of activated ERK2 to reside within the nucleus, thus blocking ERK-dependent transcriptional responsiveness of ELK-1, GATA4, and the atrial natriuretic factor promoter. Finally, FHL2 partially antagonized the cardiac hypertrophic response induced by activated MEK-1, GATA4, and phenylephrine agonist stimulation. Collectively, these results suggest that FHL2 serves a repressor function in cardiomyocytes through its ability to inhibit ERK1/2 transcriptional coupling.

scholarly journals Extracellular signal-regulated kinase mediates chromatin rewiring and lineage transformation in lung cancer

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Yusuke Inoue ◽  
Ana Nikolic ◽  
Dylan Farnsworth ◽  
Rocky Shi ◽  
Fraser D Johnson ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Mapk Pathway ◽  
Neuroendocrine Differentiation ◽  
Therapy Resistance ◽  
Mapk Signaling ◽  
Chromatin Accessibility ◽  
Extracellular Signal Regulated Kinase ◽  
Pathway Activation ◽  
Extracellular Signal ◽  
Ets Factors

Small-cell lung cancer (SCLC) is neuroendocrine in origin and rarely contains mutations in the MAPK pathway. Likewise, non-SCLC (NSCLC) that transform to SCLC concomitantly with development of therapy resistance downregulate MAPK signaling, suggesting an inverse relationship between pathway activation and lineage state. To test this, we activated MAPK in SCLC through expression of mutant KRAS or EGFR, which revealed suppression of the neuroendocrine differentiation via ERK. We found that ERK induces expression of ETS factors that mediate transformation into a NSCLC-like state. ATAC-seq demonstrated ERK-driven changes in chromatin accessibility at putative regulatory regions and global chromatin rewiring at neuroendocrine and ETS transcriptional targets. Further, induction of ETS factors and suppression of neuroendocrine differentiation were dependent on histone acetyltransferases CBP/p300. Overall, we describe how the ERK-CBP/p300-ETS axis promotes a lineage shift between neuroendocrine and non-neuroendocrine phenotypes and provide rationale for the disruption of this program during transformation-driven resistance to targeted therapy.

scholarly journals Inhibition of BRD4 inhibits proliferation and promotes apoptosis of psoriatic keratinocytes

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Xiaohui Sun ◽  
Pengfei Yang
Keyword(s):  
Mapk Pathway ◽  
Immunohistochemical Analysis ◽  
Severity Index ◽  
Mapk Signaling ◽  
Inflammatory Factors ◽  
Hacat Cells ◽  
Mice Model ◽  
Tnf Α ◽  
Related Proteins

Abstract Background Psoriasis is a common chronic recurrent inflammatory skin disease. The pathogenesis of psoriasis, such as other autoimmune diseases, is still unclear, which brings great difficulties to the treatment. This study aimed to investigate the role of bromine domain protein 4 (BRD4) in affecting the psoriatic keratinocytes. Methods Imiquimod-induced psoriasis mice model and TNF-α or IL-17A induced HaCAT cells, an experimental model in vitro for psoriasis, were constructed. The pathological skin changes at the back of mice were observed by hematoxylin and eosin (H&E) assay and evaluated by psoriasis area and severity index (PASI). KI67 expression and keratinocyte apoptosis at the skin tissues were, respectively, detected by Immunohistochemical analysis and TUNEL assay. The inflammatory factors in mice serum and culture supernatant were determined by ELISA assay. The related proteins expression of proliferation, apoptosis and MAPK pathway were detected by Western blot analysis. Results BRD4 expression was upregulated in injured skin on the back of imiquimod-induced mice and (+)-JQ1 relieved the skin injury by suppressing the inflammation and promoting apoptosis of keratinocytes. Consistently, BRD4 expression was also increased in TNF-α or IL-17A induced HaCAT cells. (+)-JQ1 suppressed the viability and inflammation, and promoted apoptosis of TNF-α or IL-17A induced HaCAT cells. In addition, the MAPK signaling pathway was inhibited by (+)-JQ1 whether in mice or HaCAT cells. Conclusions Inhibition of BRD4 inhibited proliferation and inflammation and promoted apoptosis of psoriatic keratinocytes.

scholarly journals The MAPK hypothesis: immune-regulatory effects of MAPK-pathway genetic dysregulations and implications for breast cancer immunotherapy

2017 ◽  
Vol 1 (5) ◽  
pp. 429-445 ◽  
Author(s):  
Davide Bedognetti ◽  
Jessica Roelands ◽  
Julie Decock ◽  
Ena Wang ◽  
Wouter Hendrickx
Keyword(s):  
Breast Cancer ◽  
Cell Function ◽  
Checkpoint Inhibitors ◽  
Mapk Pathway ◽  
Treatment Resistance ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Mapk Pathways ◽  
Wide Range ◽  
Regulatory Effects

With the advent of checkpoint inhibition, immunotherapy has revolutionized the clinical management of several cancers, but has demonstrated limited efficacy in mammary carcinoma. Transcriptomic profiling of cancer samples defined distinct immunophenotypic categories characterized by different prognostic and predictive connotations. In breast cancer, genomic alterations leading to the dysregulation of mitogen-activated protein kinase (MAPK) pathways have been linked to an immune-silent phenotype associated with poor outcome and treatment resistance. These aberrations include mutations of MAP3K1 and MAP2K4, amplification of KRAS, BRAF, and RAF1, and truncations of NF1. Anticancer therapies targeting MAPK signaling by BRAF and MEK inhibitors have demonstrated clear immunologic effects. These off-target properties could be exploited to convert the immune-silent tumor phenotype into an immune-active one. Preclinical evidence supports that MAPK-pathway inhibition can dramatically increase the efficacy of immunotherapy. In this review, we provide a detailed overview of the immunomodulatory impact of MAPK-pathway blockade through BRAF and MEK inhibitions. While BRAF inhibition might be relevant in melanoma only, MEK inhibition is potentially applicable to a wide range of tumors. Context-dependent similarities and differences of MAPK modulation will be dissected, in light of the complexity of the MAPK pathways. Therapeutic strategies combining the favorable effects of MAPK-oriented interventions on the tumor microenvironment while maintaining T-cell function will be presented. Finally, we will discuss recent studies highlighting the rationale for the implementation of MAPK-interference approaches in combination with checkpoint inhibitors and immune agonists in breast cancer.

scholarly journals A Novel 14-Kilodalton Protein Interacts with the Mitogen-Activated Protein Kinase Scaffold Mp1 on a Late Endosomal/Lysosomal Compartment

2001 ◽  
Vol 152 (4) ◽  
pp. 765-776 ◽  
Author(s):  
Winfried Wunderlich ◽  
Irene Fialka ◽  
David Teis ◽  
Arno Alpi ◽  
Andrea Pfeifer ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Protein Complexes ◽  
Cell Types ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Scaffolding Protein ◽  
Interacting Protein ◽  
Late Endosomes ◽  
Mitogen Activated Protein

We have identified a novel, highly conserved protein of 14 kD copurifying with late endosomes/lysosomes on density gradients. The protein, now termed p14, is peripherally associated with the cytoplasmic face of late endosomes/lysosomes in a variety of different cell types. In a two-hybrid screen with p14 as a bait, we identified the mitogen-activated protein kinase (MAPK) scaffolding protein MAPK/extracellular signal–regulated kinase (ERK) kinase (MEK) partner 1 (MP1) as an interacting protein. We confirmed the specificity of this interaction in vitro by glutathione S-transferase pull-down assays and by coimmunoprecipitation, cosedimentation on glycerol gradients, and colocalization. Moreover, expression of a plasma membrane–targeted p14 causes mislocalization of coexpressed MP1. In addition, we could reconstitute protein complexes containing the p14–MP1 complex associated with ERK and MEK in vitro. The interaction between p14 and MP1 suggests a MAPK scaffolding activity localized to the cytoplasmic surface of late endosomes/lysosomes, thereby combining catalytic scaffolding and subcellular compartmentalization as means to modulate MAPK signaling within a cell.

STYX: a versatile pseudophosphatase

2017 ◽  
Vol 45 (2) ◽  
pp. 449-456 ◽  
Author(s):  
Veronika Reiterer ◽  
Krzysztof Pawłowski ◽  
Hesso Farhan
Keyword(s):  
Protein Tyrosine Phosphatase ◽  
Regulatory Mechanism ◽  
Tyrosine Phosphatase ◽  
Biological Significance ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Interacting Protein ◽  
Modes Of Action ◽  
Mitogen Activated Protein ◽  
The One

The pseudophosphatase STYX (serine/threonine/tyrosine interacting protein) is a catalytically inactive member of the protein tyrosine phosphatase family. We perform a phylogenetic analysis of STYX and ask how far does the pseudoenzyme status of STYX reaches in evolution. Based on our previous work, we use STYX as a showcase to discuss four basic modes of action that any given pseudoenzyme may exert. Our previous work on the effect of STYX on mitogen-activated protein kinase (MAPK) signaling led us to identify two complementary modes of action. On the one hand, STYX competes with active phosphatases for binding to MAPKs. On the other hand, STYX acts as a nuclear anchor for MAPKs, affecting their nucleo-cytoplasmic shuttling. Finally, we discuss our recent work on the regulation of FBXW7 by this pseudophosphatase and how it affects the ubiquitylation and degradation of its substrates. We discuss the biological significance of this regulatory mechanism and use it as an example for the versatility of pseudoenzymes that may divert away from merely regulating their active homologs.

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