scholarly journals Stress- and mitogen-induced phosphorylation of the synapse-associated protein SAP90/PSD-95 by activation of SAPK3/p38gamma and ERK1/ERK2

2004 ◽  
Vol 380 (1) ◽  
pp. 19-30 ◽  
Author(s):  
Guadalupe SABIO ◽  
Suzana REUVER ◽  
Carmen FEIJOO ◽  
Masato HASEGAWA ◽  
Gareth M. THOMAS ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Protein Interactions ◽  
Pdz Domain ◽  
Mitogen Activated Protein Kinase ◽  
Protein Protein Interactions ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
A Cell ◽  
Cellular Stresses ◽  
Sb 203580

SAPK3 (stress-activated protein kinase-3, also known as p38γ) is a member of the mitogen-activated protein kinase family; it phosphorylates substrates in response to cellular stress, and has been shown to bind through its C-terminal sequence to the PDZ domain of α1-syntrophin. In the present study, we show that SAP90 [(synapse-associated protein 90; also known as PSD-95 (postsynaptic density-95)] is a novel physiological substrate for both SAPK3/p38γ and the ERK (extracellular-signal-regulated protein kinase). SAPK3/p38γ binds preferentially to the third PDZ domain of SAP90 and phosphorylates residues Thr287 and Ser290in vitro, and Ser290 in cells in response to cellular stresses. Phosphorylation of SAP90 is dependent on the binding of SAPK3/p38γ to the PDZ domain of SAP90. It is not blocked by SB 203580, which inhibits SAPK2a/p38α and SAPK2b/p38β but not SAPK3/p38γ, or by the ERK pathway inhibitor PD 184352. However, phosphorylation is abolished when cells are treated with a cell-permeant Tat fusion peptide that disrupts the interaction of SAPK3/p38γ with SAP90. ERK2 also phosphorylates SAP90 at Thr287 and Ser290in vitro, but this does not require PDZ-dependent binding. SAP90 also becomes phosphorylated in response to mitogens, and this phosphorylation is prevented by pretreatment of the cells with PD 184352, but not with SB 203580. In neurons, SAP90 and SAPK3/p38γ co-localize and they are co-immunoprecipitated from brain synaptic junctional preparations. These results demonstrate that SAP90 is a novel binding partner for SAPK3/p38γ, a first physiological substrate described for SAPK3/p38γ and a novel substrate for ERK1/ERK2, and that phosphorylation of SAP90 may play a role in regulating protein–protein interactions at the synapse in response to adverse stress- or mitogenrelated stimuli.

scholarly journals A Journey Through Mitogen-Activated Protein Kinase and Ochratoxin A Interactions

2009 ◽  
Vol 60 (4) ◽  
pp. 449-456 ◽  
Author(s):  
Lada Rumora ◽  
Tihana Grubišić
Keyword(s):  
Protein Kinase ◽  
Ochratoxin A ◽  
Mitogen Activated Protein Kinase ◽  
Balkan Endemic Nephropathy ◽  
Cytotoxic Action ◽  
Extracellular Signal ◽  
Increased Risk ◽  
Mitogen Activated Protein ◽  
Endemic Nephropathy ◽  
A Cell

A Journey Through Mitogen-Activated Protein Kinase and Ochratoxin A InteractionsOchratoxin A (OTA) is a ubiquitous mycotoxin with potential nephrotoxic, carcinogenic, and cytotoxic action. It has been proposed that OTA might be involved in the development of Balkan endemic nephropathy, which is associated with an increased risk of urinary tract tumours, and of other forms of interstitial nephritis. Cell susceptibility to OTA mainly depends on mycotoxin concentrations, duration of exposure, and intracellular molecular and genetic context. OTA can affect a cell by stimulating or inhibiting certain signalling pathways such as mitogen-activated protein kinase (MAPK). Three major mammalian MAPKs have been described: extracellular signal-regulated protein kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 MAPK. All MAPKs regulate diverse cellular programmes, but in most cases ERKs have been linked to cell survival, while JNKs, and p38 MAPKs have been implicated in cell death by apoptosis. This review looks into OTA-mediated MAPK activation and its effects.

scholarly journals Monitoring protein–protein interactions in mammalian cells by trans-SUMOylation

2011 ◽  
Vol 438 (3) ◽  
pp. 495-503 ◽  
Author(s):  
Ratnesh K. Srivastav ◽  
Susan Schwede ◽  
Malte Klaus ◽  
Jessica Schwermann ◽  
Matthias Gaestel ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Protein Interactions ◽  
Mammalian Cells ◽  
Glutathione Transferase ◽  
Mitogen Activated Protein Kinase ◽  
Protein Protein Interactions ◽  
Sumoylation Site ◽  
Endogenous Expression ◽  
Mitogen Activated Protein

Protein–protein interactions are essential for almost all cellular processes, hence understanding these processes mainly depends on the identification and characterization of the relevant protein–protein interactions. In the present paper, we introduce the concept of TRS (trans-SUMOylation), a new method developed to identify and verify protein–protein interactions in mammalian cells in vivo. TRS utilizes Ubc9-fusion proteins that trans-SUMOylate co-expressed interacting proteins. Using TRS, we analysed interactions of 65 protein pairs co-expressed in HEK (human embryonic kidney)-293 cells. We identified seven new and confirmed 16 known protein interactions, which were determined via endogenous SUMOylation sites of the binding partners or by using SUMOylation-site tags respectively. Four of the new protein interactions were confirmed by GST (glutathione transferase) pull-down and the p38α–Edr2 interaction was verified by co-localization analysis. Functionally, this p38α–Edr2 interaction could possibly be involved in the recruitment of p38α to the polycomb chromatin-remodelling complex to phosphorylate Bmi1. We also used TRS to characterize protein-interaction domains of the protein kinase pairs p38α–MK2 [MK is MAPK (mitogen-activated protein kinase)-activated protein kinase] and ERK3 (extracellular-signal-regulated kinase 3)–MK5 and of the p38α–p53 complex. The ability of TRS to monitor protein interactions in mammalian cells in vivo at levels similar to endogenous expression makes it an excellent new tool that can help in defining the protein interactome of mammalian cells.

scholarly journals Meaningful relationships: the regulation of the Ras/Raf/MEK/ERK pathway by protein interactions

2000 ◽  
Vol 351 (2) ◽  
pp. 289-305 ◽  
Author(s):  
Walter KOLCH
Keyword(s):  
Protein Interactions ◽  
Mitogen Activated Protein Kinase ◽  
Protein Protein Interactions ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Substrate Phosphorylation ◽  
Meaningful Relationships ◽  
Kinase Pathway

The Ras/Raf/MEK (mitogen-activated protein kinase/ERK kinase)/ERK (extracellular-signal-regulated kinase) pathway is at the heart of signalling networks that govern proliferation, differentiation and cell survival. Although the basic regulatory steps have been elucidated, many features of this pathway are only beginning to emerge. This review focuses on the role of protein–protein interactions in the regulation of this pathway, and how they contribute to co-ordinate activation steps, subcellular redistribution, substrate phosphorylation and cross-talk with other signalling pathways.

scholarly journals Exercise-induced mitogen-activated protein kinase signalling in skeletal muscle

2004 ◽  
Vol 63 (2) ◽  
pp. 227-232 ◽  
Author(s):  
Yun Chau Long ◽  
Ulrika Widegren ◽  
Juleen R. Zierath
Keyword(s):  
Skeletal Muscle ◽  
Protein Kinase ◽  
Muscle Contraction ◽  
Mitogen Activated Protein Kinase ◽  
Mapk Cascades ◽  
Extracellular Signal ◽  
Mapk Signalling ◽  
Mitogen Activated Protein ◽  
Exercise Induced ◽  
Response To Exercise

Exercise training improves glucose homeostasis through enhanced insulin sensitivity in skeletal muscle. Muscle contraction through physical exercise is a physiological stimulus that elicits multiple biochemical and biophysical responses and therefore requires an appropriate control network. Mitogen-activated protein kinase (MAPK) signalling pathways constitute a network of phosphorylation cascades that link cellular stress to changes in transcriptional activity. MAPK cascades are divided into four major subfamilies, including extracellular signal-regulated kinases 1 and 2, p38 MAPK, c-Jun NH2-terminal kinase and extracellular signal-regulated kinase 5. The present review will present the current understanding of parallel MAPK signalling in human skeletal muscle in response to exercise and muscle contraction, with an emphasis on identifying potential signalling mechanisms responsible for changes in gene expression.

scholarly journals TRAF6-Dependent Mitogen-Activated Protein Kinase Activation Differentially Regulates the Production of Interleukin-12 by Macrophages in Response to Toxoplasma gondii

2004 ◽  
Vol 72 (10) ◽  
pp. 5662-5667 ◽  
Author(s):  
Nicola J. Mason ◽  
Jim Fiore ◽  
Takashi Kobayashi ◽  
Katherine S. Masek ◽  
Yongwon Choi ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Toxoplasma Gondii ◽  
Signaling Pathways ◽  
Intracellular Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Interleukin 12 ◽  
Wild Type ◽  
Kinase Activation ◽  
Extracellular Signal ◽  
Mitogen Activated Protein

ABSTRACT The production of interleukin-12 (IL-12) is critical to the development of innate and adaptive immune responses required for the control of intracellular pathogens. Many microbial products signal through Toll-like receptors (TLR) and activate NF-κB family members that are required for the production of IL-12. Recent studies suggest that components of the TLR pathway are required for the production of IL-12 in response to the parasite Toxoplasma gondii; however, the production of IL-12 in response to this parasite is independent of NF-κB activation. The adaptor molecule TRAF6 is involved in TLR signaling pathways and associates with serine/threonine kinases involved in the activation of both NF-κB and mitogen-activated protein kinase (MAPK). To elucidate the intracellular signaling pathways involved in the production of IL-12 in response to soluble toxoplasma antigen (STAg), wild-type and TRAF6−/− mice were inoculated with STAg, and the production of IL-12(p40) was determined. TRAF6−/− mice failed to produce IL-12(p40) in response to STAg, and TRAF6−/− macrophages stimulated with STAg also failed to produce IL-12(p40). Studies using Western blot analysis of wild-type and TRAF6−/− macrophages revealed that stimulation with STAg resulted in the rapid TRAF6-dependent phosphorylation of p38 and extracellular signal-related kinase, which differentially regulated the production of IL-12(p40). The studies presented here demonstrate for the first time that the production of IL-12(p40) in response to toxoplasma is dependent upon TRAF6 and p38 MAPK.

scholarly journals Cross-talk between IRAK-4 and the NADPH oxidase1

2007 ◽  
Vol 403 (3) ◽  
pp. 451-461 ◽  
Author(s):  
Sandrine Pacquelet ◽  
Jennifer L. Johnson ◽  
Beverly A. Ellis ◽  
Agnieszka A. Brzezinska ◽  
William S. Lane ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Nadph Oxidase ◽  
P38 Mapk ◽  
Interleukin 1 ◽  
Mitogen Activated Protein Kinase ◽  
Free System ◽  
Mitogen Activated Protein ◽  
A Cell ◽  
Tlr4 Activation

Exposure of neutrophils to LPS (lipopolysaccharide) triggers their oxidative response. However, the relationship between the signalling downstream of TLR4 (Toll-like receptor 4) after LPS stimulation and the activation of the oxidase remains elusive. Phosphorylation of the cytosolic factor p47phox is essential for activation of the NADPH oxidase. In the present study, we examined the hypothesis that IRAK-4 (interleukin-1 receptor-associated kinase-4), the main regulatory kinase downstream of TLR4 activation, regulates the NADPH oxidase through phosphorylation of p47phox. We show that p47phox is a substrate for IRAK-4. Unlike PKC (protein kinase C), IRAK-4 phosphorylates p47phox not only at serine residues, but also at threonine residues. Target residues were identified by tandem MS, revealing a novel threonine-rich regulatory domain. We also show that p47phox is phosphorylated in granulocytes in response to LPS stimulation. LPS-dependent phosphorylation of p47phox was enhanced by the inhibition of p38 MAPK (mitogen-activated protein kinase), confirming that the kinase operates upstream of p38 MAPK. IRAK-4-phosphorylated p47phox activated the NADPH oxidase in a cell-free system, and IRAK-4 overexpression increased NADPH oxidase activity in response to LPS. We have shown that endogenous IRAK-4 interacts with p47phox and they co-localize at the plasma membrane after LPS stimulation, using immunoprecipitation assays and immunofluorescence microscopy respectively. IRAK-4 was activated in neutrophils in response to LPS stimulation. We found that Thr133, Ser288 and Thr356, targets for IRAK-4 phosphorylation in vitro, are also phosphorylated in endogenous p47phox after LPS stimulation. We conclude that IRAK-4 phosphorylates p47phox and regulates NADPH oxidase activation after LPS stimulation.

Sign in / Sign up

Export Citation Format

Share Document