scholarly journals Rational Design and Synthesis of Diverse Pyrimidine Molecules Bearing Sulfonamide Moiety as Novel ERK Inhibitors

2019 ◽  
Vol 20 (22) ◽  
pp. 5592 ◽  
Author(s):  
Halawa ◽  
Eskandrani ◽  
Elgammal ◽  
Hassan ◽  
Hassan ◽  
...  
Keyword(s):  
Map Kinase ◽  
Rational Design ◽  
Binding Pocket ◽  
Kinase Domain ◽  
Effector Proteins ◽  
Cellular Functions ◽  
Oncogenic Signaling ◽  
Design And Synthesis ◽  
Mitogen Activated Protein ◽  
Erk Kinase

Protein kinases orchestrate diverse cellular functions; however, their dysregulation is linked to metabolic dysfunctions, associated with many diseases, including cancer. Mitogen-Activated Protein (MAP) kinase is a notoriously oncogenic signaling pathway in human malignancies, where the extracellular signal-regulated kinases (ERK1/2) are focal serine/threonine kinases in the MAP kinase module with numerous cytosolic and nuclear mitogenic effector proteins. Subsequently, hampering the ERK kinase activity by small molecule inhibitors is a robust strategy to control the malignancies with aberrant MAP kinase signaling cascades. Consequently, new heterocyclic compounds, containing a sulfonamide moiety, were rationally designed, aided by the molecular docking of the starting reactant 1-(4-((4-methylpiperidin-1-yl)sulfonyl)phenyl)ethan-1-one (3) at the ATP binding pocket of the ERK kinase domain, which was relying on the molecular extension tactic. The identities of the synthesized compounds (4–33) were proven by their spectral data and elemental analysis. The target compounds exhibited pronounced anti-proliferative activities against the MCF-7, HepG-2, and HCT-116 cancerous cell lines with potencies reaching a 2.96 μM for the most active compound (22). Moreover, compounds 5, 9, 10b, 22, and 28 displayed a significant G2/M phase arrest and induction of the apoptosis, which was confirmed by the cell cycle analysis and the flow cytometry. Thus, the molecular extension of a small fragment bounded at the ERK kinase domain is a valid tactic for the rational synthesis of the ERK inhibitors to control various human malignancies.

scholarly journals Dominant Mutations of Drosophila MAP Kinase Kinase and Their Activities in Drosophila and Yeast MAP Kinase Cascades

Genetics ◽  
1997 ◽  
Vol 146 (1) ◽  
pp. 263-273 ◽  
Author(s):  
Young-Mi Lim ◽  
Leo Tsuda ◽  
Yoshihiro H Inoue ◽  
Kenji Irie ◽  
Takashi Adachi-Yamada ◽  
...  
Keyword(s):  
Map Kinase ◽  
Tyrosine Kinases ◽  
Egf Receptor ◽  
Kinase Domain ◽  
Nucleotide Sequencing ◽  
Gain Of Function ◽  
Highly Sensitive ◽  
Mitogen Activated Protein ◽  
Signal Specificity ◽  
Map Kinase Kinase

Eight alleles of Dsor1 encoding a Drosophila homologue of mitogen-activated protein (MAP) kinase kinase were obtained as dominant suppressors of the MAP kinase kinase kinase D-raf. These Dsor1 alleles themselves showed no obvious phenotypic consequences nor any effect on the viability of the flies, although they were highly sensitive to upstream signals and strongly interacted with gain-of-function mutations of upstream factors. They suppressed mutations for receptor tyrosine kinases (RTKs); torso (tor), sevenless (sev) and to a lesser extent Drosophila EGF receptor (DER). Furthermore, the Dsor1 alleles showed no significant interaction with gain-of-function mutations of DER. The observed difference in activity of the Dsor1 alleles among the RTK pathways suggests Dsor1 is one of the components of the pathway that regulates signal specificity. Expression of Dsor1 in budding yeast demonstrated that Dsor1 can activate yeast MAP kinase homologues if a proper activator of Dsor1 is coexpressed. Nucleotide sequencing of the Dsor1 mutant genes revealed that most of the mutations are associated with amino acid changes at highly conserved residues in the kinase domain. The results suggest that they function as suppressors due to increased reactivity to upstream factors.

scholarly journals IQGAP1 Is a Scaffold for Mitogen-Activated Protein Kinase Signaling

2005 ◽  
Vol 25 (18) ◽  
pp. 7940-7952 ◽  
Author(s):  
Monideepa Roy ◽  
Zhigang Li ◽  
David B. Sacks
Keyword(s):  
Growth Factor ◽  
Map Kinase ◽  
Mitogen Activated Protein Kinase ◽  
Kinase Signaling ◽  
Cellular Functions ◽  
Molecular Scaffold ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Erk Activity

ABSTRACT IQGAP1 modulates many cellular functions such as cell-cell adhesion, transcription, cytoskeletal architecture, and selected signaling pathways. We previously documented that IQGAP1 binds extracellular signal-regulated kinase (ERK) 2 and regulates growth factor-stimulated ERK activity. Here we show that MEK, the molecule immediately upstream of ERK in the Ras/mitogen-activated protein (MAP) kinase signaling cascade, also interacts directly with IQGAP1. Both MEK1 and MEK2 bound IQGAP1 in vitro and coimmunoprecipitated with IQGAP1. The addition of ERK2 enhanced by fourfold the in vitro interaction of MEK2 with IQGAP1 without altering binding of MEK1. Similarly, ERK1 promoted MEK binding to IQGAP1, but either MEK protein altered the association between IQGAP1 and ERK. Epidermal growth factor (EGF) differentially regulated binding, enhancing MEK1 interaction while reducing MEK2 binding to IQGAP1. In addition, both knockdown and overexpression of IQGAP1 reduced EGF-stimulated activation of MEK and ERK. Analyses with selective IQGAP1 mutant constructs indicated that MEK binding is crucial for IQGAP1 to modulate EGF activation of ERK. Our data strongly suggest that IQGAP1 functions as a molecular scaffold in the Ras/MAP kinase pathway.

scholarly journals Ribosomal S6 Kinase (RSK) Regulates Phosphorylation of Filamin A on an Important Regulatory Site

2004 ◽  
Vol 24 (7) ◽  
pp. 3025-3035 ◽  
Author(s):  
Michele S. Woo ◽  
Yasutaka Ohta ◽  
Isaac Rabinovitz ◽  
Thomas P. Stossel ◽  
John Blenis
Keyword(s):  
Map Kinase ◽  
Kinase Domain ◽  
Filamin A ◽  
S6 Kinase ◽  
Membrane Ruffling ◽  
Cellular Processes ◽  
Mitogen Activated Protein ◽  
Epidermal Growth ◽  
Ribosomal S6 Kinase

ABSTRACT The Ras-mitogen-activated protein (Ras-MAP) kinase pathway regulates various cellular processes, including gene expression, cell proliferation, and survival. Ribosomal S6 kinase (RSK), a key player in this pathway, modulates the activities of several cytoplasmic and nuclear proteins via phosphorylation. Here we report the characterization of the cytoskeletal protein filamin A (FLNa) as a membrane-associated RSK target. We show that the N-terminal kinase domain of RSK phosphorylates FLNa on Ser2152 in response to mitogens. Inhibition of MAP kinase signaling with UO126 or mutation of Ser2152 to Ala on FLNa prevents epidermal growth factor (EGF)-stimulated phosphorylation of FLNa in vivo. Furthermore, phosphorylation of FLNa on Ser2152 is significantly enhanced by the expression of wild-type RSK and antagonized by kinase-inactive RSK or specific reduction of endogenous RSK. Strikingly, EGF-induced, FLNa-dependent migration of human melanoma cells is significantly reduced by UO126 treatment. Together, these data provide substantial evidence that RSK phosphorylates FLNa on Ser2152 in vivo. Given that phosphorylation of FLNa on Ser2152 is required for Pak1-mediated membrane ruffling, our results suggest a novel role for RSK in the regulation of the actin cytoskeleton.

Structures of the PKC-ι kinase domain in its ATP-bound and apo forms reveal defined structures of residues 533–551 in the C-terminal tail and their roles in ATP binding

2010 ◽  
Vol 66 (5) ◽  
pp. 577-583 ◽  
Author(s):  
Tetsuo Takimura ◽  
Kenji Kamata ◽  
Kazuhiro Fukasawa ◽  
Hirokazu Ohsawa ◽  
Hideya Komatani ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Binding Pocket ◽  
Kinase Domain ◽  
Van Der Waals Interactions ◽  
Side Chain ◽  
Phosphoryl Transfer ◽  
Atp Binding ◽  
Cellular Functions ◽  
Substrate Complex ◽  
Wide Range

Protein kinase C (PKC) plays an essential role in a wide range of cellular functions. Although crystal structures of the PKC-θ, PKC-ι and PKC-βII kinase domains have previously been determined in complexes with small-molecule inhibitors, no structure of a PKC–substrate complex has been determined. In the previously determined PKC-ι complex, residues 533–551 in the C-terminal tail were disordered. In the present study, crystal structures of the PKC-ι kinase domain in its ATP-bound and apo forms were determined at 2.1 and 2.0 Å resolution, respectively. In the ATP complex, the electron density of all of the C-terminal tail residues was well defined. In the structure, the side chain of Phe543 protrudes into the ATP-binding pocket to make van der Waals interactions with the adenine moiety of ATP; this is also observed in other AGC kinase structures such as binary and ternary substrate complexes of PKA and AKT. In addition to this interaction, the newly defined residues around the turn motif make multiple hydrogen bonds to glycine-rich-loop residues. These interactions reduce the flexibility of the glycine-rich loop, which is organized for ATP binding, and the resulting structure promotes an ATP conformation that is suitable for the subsequent phosphoryl transfer. In the case of the apo form, the structure and interaction mode of the C-terminal tail of PKC-ι are essentially identical to those of the ATP complex. These results indicate that the protein structure is pre-organized before substrate binding to PKC-ι, which is different from the case of the prototypical AGC-branch kinase PKA.

scholarly journals YopJ of Yersinia spp. Is Sufficient To Cause Downregulation of Multiple Mitogen-Activated Protein Kinases in Eukaryotic Cells

1999 ◽  
Vol 67 (2) ◽  
pp. 708-716 ◽  
Author(s):  
Lance E. Palmer ◽  
Alessandra R. Pancetti ◽  
Steven Greenberg ◽  
James B. Bliska
Keyword(s):  
Map Kinase ◽  
Map Kinases ◽  
Cell Interaction ◽  
Small Gtpase ◽  
Effector Proteins ◽  
Eukaryotic Cells ◽  
Cell Periphery ◽  
Necrosis Factor Alpha ◽  
Type Iii ◽  
Mitogen Activated Protein

ABSTRACT Pathogenic Yersinia spp. utilize a plasmid-encoded type III secretion system to deliver a set of Yop effector proteins into eukaryotic cells. Previous studies have shown that the effector YopJ is required for Yersinia to cause downregulation of the mitogen-activated protein (MAP) kinases c-Jun N-terminal kinase (JNK), p38, and extracellular signal-regulated kinase (ERK) 1 and 2 in infected macrophages. Here we demonstrate that YopJ is sufficient to cause downregulation of multiple MAP kinases in eukaryotic cells. Cellular fractionation experiments confirmed that YopJ is delivered into the cytoplasmic fraction of macrophages by the type III system. Production of YopJ in COS-1 cells by transfection significantly reduced (5- to 10-fold) activation of JNK, p38, and ERK in response to several different stimuli, including serum and tumor necrosis factor alpha. JNK activation mediated by RacV12, an activated mutant of Rac1, was also blocked by YopJ in COS-1 cells, indicating that YopJ acts downstream of this small GTPase to downregulate MAP kinase signaling. Analysis of transfected COS-1 cells by immunofluorescence microscopy revealed that YopJ is recruited from the cytoplasmic compartment to the cell periphery in response to stimuli (e.g., serum) that induce membrane ruffling. These data indicate that YopJ functions as a “MAP kinase toxin” to selectively block nuclear responses that are triggered byYersinia-host cell interaction.

scholarly journals Extracellular Signal-Regulated Kinase 7 (ERK7), a Novel ERK with a C-Terminal Domain That Regulates Its Activity, Its Cellular Localization, and Cell Growth

1999 ◽  
Vol 19 (2) ◽  
pp. 1301-1312 ◽  
Author(s):  
Mark K. Abe ◽  
Wen-Liang Kuo ◽  
Marc B. Hershenson ◽  
Marsha Rich Rosner
Keyword(s):  
Map Kinase ◽  
Cellular Localization ◽  
Map Kinases ◽  
Kinase Domain ◽  
Extracellular Signal Regulated Kinase ◽  
Terminal Domain ◽  
Inhibition Of Growth ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
And Function

ABSTRACT Mitogen-activated protein (MAP) kinases play distinct roles in a variety of cellular signaling pathways and are regulated through multiple mechanisms. In this study, a novel 61-kDa member of the MAP kinase family, termed extracellular signal-regulated kinase 7 (ERK7), has been cloned and characterized. Although it has the signature TEY activation motif of ERK1 and ERK2, ERK7 is not activated by extracellular stimuli that typically activate ERK1 and ERK2 or by common activators of c-Jun N-terminal kinase (JNK) and p38 kinase. Instead, ERK7 has appreciable constitutive activity in serum-starved cells that is dependent on the presence of its C-terminal domain. Interestingly, the C-terminal tail, not the kinase domain, of ERK7 regulates its nuclear localization and inhibition of growth. Taken together, these results elucidate a novel type of MAP kinase whereby interactions via its C-terminal tail, rather than extracellular signal-mediated activation cascades, regulate its activity, localization, and function.

scholarly journals Interleukin-6-induced STAT3 transactivation and Ser727 phosphorylation involves Vav, Rac-1 and the kinase SEK-1/MKK-4 as signal transduction components

2000 ◽  
Vol 347 (1) ◽  
pp. 89-96 ◽  
Author(s):  
Jan-Jacob SCHURINGA ◽  
Luigi J. C. JONK ◽  
Wim H. A. DOKTER ◽  
Edo VELLENGA ◽  
Wiebe KRUIJER
Keyword(s):  
Signal Transduction ◽  
Protein Kinase ◽  
Map Kinase ◽  
Hepg2 Cells ◽  
Mek Inhibitor ◽  
Dominant Negative ◽  
Negative Regulator ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Erk Kinase

In the present study, signal transducer and activator of transcription 3 (STAT3) Ser727 phosphorylation and transactivation was investigated in relation to activation of mitogen-activated protein (MAP) kinase family members including extracellular-signal-regulated protein kinase (ERK)-1, c-Jun N-terminal kinase (JNK)-1 and p38 (‘reactivating kinase’) in response to interleukin (IL)-6 stimulation. Although IL-6 can activate ERK-1 in HepG2 cells, STAT3 transactivation and Ser727 phosphorylation were not reduced by using the MAP kinase/ERK kinase (MEK) inhibitor PD98059 or by overexpression of dominant-negative Raf. IL-6 did not activate JNK-1 in HepG2 cells and STAT3 was a poor substrate for JNK-1 activated by anisomycin, excluding a role for JNK1 in IL-6-induced STAT3 activation. However, SEK-1/MKK-4 [where SEK-1 stands for stress-activated protein kinase (SAPK)/ERK kinase 1, and MKK-4 stands for MAP kinase kinase 4] was activated in response to IL-6 and overexpression of dominant-negative SEK-1/MKK-4(A-L) reduced both IL-6-induced STAT3 Ser727 phosphorylation as well as STAT3 transactivation. Subsequently, the SEK-1/MKK-4 upstream components Vav, Rac-1 and MEKK were identified as components of a signal transduction cascade that leads to STAT3 transactivation in response to IL-6 stimulation. Furthermore, inhibition of p38 kinase activity with the inhibitor SB203580 did not block STAT3 Ser727 phosphorylation but rather increased both basal as well as IL-6-induced STAT3 transactivation, indicating that p38 may act as a negative regulator of IL-6-induced STAT3 transactivation through a presently unknown mechanism. In conclusion, these data indicate that IL-6-induced STAT3 transactivation and Ser727 phosphorylation is independent of ERK-1 or JNK-1 activity, but involves a gp130 receptor-signalling cascade that includes Vav, Rac-1, MEKK and SEK-1/MKK-4 as signal transduction components.

scholarly journals Evolutionary Diversification of Host-Targeted Bartonella Effectors Proteins Derived from a Conserved FicTA Toxin-Antitoxin Module

2021 ◽  
Vol 9 (8) ◽  
pp. 1645
Author(s):  
Tilman Schirmer ◽  
Tjaart A. P. de Beer ◽  
Stefanie Tamegger ◽  
Alexander Harms ◽  
Nikolaus Dietz ◽  
...  
Keyword(s):  
Structural Changes ◽  
Molecular Mechanisms ◽  
Phylogenetic Analyses ◽  
Substrate Binding ◽  
Binding Pocket ◽  
Effector Proteins ◽  
Host Cells ◽  
Cellular Functions ◽  
X Ray Crystallography ◽  
Evolutionary Diversification

Proteins containing a FIC domain catalyze AMPylation and other post-translational modifications (PTMs). In bacteria, they are typically part of FicTA toxin-antitoxin modules that control conserved biochemical processes such as topoisomerase activity, but they have also repeatedly diversified into host-targeted virulence factors. Among these, Bartonella effector proteins (Beps) comprise a particularly diverse ensemble of FIC domains that subvert various host cellular functions. However, no comprehensive comparative analysis has been performed to infer molecular mechanisms underlying the biochemical and functional diversification of FIC domains in the vast Bep family. Here, we used X-ray crystallography, structural modelling, and phylogenetic analyses to unravel the expansion and diversification of Bep repertoires that evolved in parallel in three Bartonella lineages from a single ancestral FicTA toxin-antitoxin module. Our analysis is based on 99 non-redundant Bep sequences and nine crystal structures. Inferred from the conservation of the FIC signature motif that comprises the catalytic histidine and residues involved in substrate binding, about half of them represent AMP transferases. A quarter of Beps show a glutamate in a strategic position in the putative substrate binding pocket that would interfere with triphosphate-nucleotide binding but may allow binding of an AMPylated target for deAMPylation or another substrate to catalyze a distinct PTM. The β-hairpin flap that registers the modifiable target segment to the active site exhibits remarkable structural variability. The corresponding sequences form few well-defined groups that may recognize distinct target proteins. The binding of Beps to promiscuous FicA antitoxins is well conserved, indicating a role of the antitoxin to inhibit enzymatic activity or to serve as a chaperone for the FIC domain before translocation of the Bep into host cells. Taken together, our analysis indicates a remarkable functional plasticity of Beps that is mostly brought about by structural changes in the substrate pocket and the target dock. These findings may guide future structure–function analyses of the highly versatile FIC domains.

scholarly journals Structural and Functional Basis for p38-MK2-Activated Rsk Signaling in Toll-Like Receptor-Stimulated Dendritic Cells

2014 ◽  
Vol 35 (1) ◽  
pp. 132-140 ◽  
Author(s):  
Rossana Zaru ◽  
Alexander J. Edgar ◽  
André Hanauer ◽  
Colin Watts
Keyword(s):  
Dendritic Cells ◽  
Map Kinase ◽  
Kinase Domain ◽  
Type I Interferons ◽  
Type I ◽  
Toll Like Receptor ◽  
Partial Explanation ◽  
Mitogen Activated Protein ◽  
Noncanonical Pathway ◽  
And Migration

Rsk kinases play important roles in several cellular processes such as proliferation, metabolism, and migration. Until recently, Rsk activation was thought to be exclusively initiated by Erk1/2, but in dendritic cells (DC) Rsk is also activated by p38 mitogen-activated protein (MAP) kinase via its downstream substrates, MK2/3. How and why this noncanonical configuration of the MAP kinase pathway is adopted by these key immune cells are not known. We demonstrate that the Erk1/2-activated C-terminal kinase domain of Rsk is dispensable for p38-MK2/3 activation and show that compared with fibroblasts, a greater fraction of p38 and MK2/3 is located in the cytosol of DC prior to stimulation, suggesting a partial explanation for the operation of the noncanonical pathway of Rsk activation in these cells. p38/MK2/3-activated Rsk phosphorylated downstream targets and is physiologically important because in plasmacytoid DC (pDC) stimulated with Toll-like receptor 7 (TLR7) agonists, Erk1/2 activation is very weak relative to p38. As a result, Rsk activation is entirely p38 dependent. We show that this unusual configuration of MAP kinase signaling contributes substantially to production of type I interferons, a hallmark of pDC activation.

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