scholarly journals The Severe Acute Respiratory Syndrome Coronavirus Nucleocapsid Protein Is Phosphorylated and Localizes in the Cytoplasm by 14-3-3-Mediated Translocation

2005 ◽  
Vol 79 (17) ◽  
pp. 11476-11486 ◽  
Author(s):  
Milan Surjit ◽  
Ravinder Kumar ◽  
Rabi N. Mishra ◽  
Malireddy K. Reddy ◽  
Vincent T. K. Chow ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Protein Interactions ◽  
Nucleocapsid Protein ◽  
Glycogen Synthase ◽  
In Silico Analysis ◽  
Mitogen Activated Protein Kinase ◽  
Regulatory Pathways ◽  
N Protein ◽  
Mitogen Activated Protein

ABSTRACT The severe acute respiratory syndrome coronavirus(SARS-CoV) nucleocapsid (N) protein is one of the four structural proteins of the virus and is predicted to be a 46-kDa phosphoprotein. Our in silico analysis predicted N to be heavily phosphorylated at multiple residues. Experimentally, we have shown in this report that the N protein of the SARS-CoV gets serine-phosphorylated by multiple kinases, in both the cytoplasm and the nucleus. The phosphoprotein is stable and localizes in the cytoplasm and coprecipitates with the membrane fraction. Also, using specific inhibitors of phosphorylation and an in vitro phosphorylation assay, we show that the nucleocapsid protein is a substrate of cyclin-dependent kinase (CDK), glycogen synthase kinase, mitogen-activated protein kinase, and casein kinase II. Further, we show that the phosphorylated protein is translocated to the cytoplasm by binding to 14-3-3 (tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein). 14-3-3 proteins are a family of highly conserved, ubiquitously expressed eukaryotic proteins that function primarily as adapters that modulate interactions between components of various cellular signaling and cell cycle regulatory pathways through phosphorylation-dependent protein-protein interactions. Coincidentally, the N protein was also found to downregulate the expression of the theta isoform of 14-3-3 (14-3-3θ), leading to the accumulation of phosphorylated N protein in the nucleus, in the absence of growth factors. Using short interfering RNA specific to 14-3-3θ we have inhibited its expression to show accumulation of phosphorylated N protein in the nucleus. Thus, the data presented here provide a possible mechanism for phosphorylation-dependent nucleocytoplasmic shuttling of the N protein. This 14-3-3-mediated transport of the phosphorylated N protein and its possible implications in interfering with the cellular machinery are discussed.

scholarly journals Severe acute respiratory syndrome coronavirus nucleocapsid protein expressed by an adenovirus vector is phosphorylated and immunogenic in mice

2005 ◽  
Vol 86 (1) ◽  
pp. 211-215 ◽  
Author(s):  
Alexander N. Zakhartchouk ◽  
Sathiyanarayanan Viswanathan ◽  
James B. Mahony ◽  
Jack Gauldie ◽  
Lorne A. Babiuk
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Immune Responses ◽  
Nucleocapsid Protein ◽  
Adenovirus Vector ◽  
Human Adenovirus ◽  
Cell Mediated Immunity ◽  
Aetiological Agent ◽  
N Protein ◽  
Adenovirus 5

Severe acute respiratory syndrome coronavirus (SARS-CoV) has been identified as the aetiological agent of SARS. Thus, vaccination against SARS-CoV may represent an effective approach towards controlling SARS. The nucleocapsid (N) protein is thought to play a role in induction of cell-mediated immunity to SARS-CoV and thus it is important to characterize this protein. In the present study, an E1/partially E3-deleted, replication-defective human adenovirus 5 (Ad5) vector (Ad5-N-V) expressing the SARS-CoV N protein was constructed. The N protein, expressed in vitro by Ad5-N-V, was of the expected molecular mass of 50 kDa and was phosphorylated. Vaccination of C57BL/6 mice with Ad5-N-V generated potent SARS-CoV-specific humoral and T cell-mediated immune responses. These results show that Ad5-N-V may potentially be used as a SARS-CoV vaccine.

scholarly journals Mutational Analysis of STE5 in the Yeast Saccharomyces cerevisiae: Application of a Differential Interaction Trap Assay for Examining Protein-Protein Interactions

Genetics ◽  
1997 ◽  
Vol 147 (2) ◽  
pp. 479-492 ◽  
Author(s):  
Carla Inouye ◽  
Namrita Dhillon ◽  
Tim Durfee ◽  
Patricia C Zambryski ◽  
Jeremy Thorner
Keyword(s):  
Protein Interactions ◽  
Mutational Analysis ◽  
Mapk Cascade ◽  
Mitogen Activated Protein Kinase ◽  
Missense Mutations ◽  
Protein Protein Interactions ◽  
Yeast Saccharomyces Cerevisiae ◽  
Mitogen Activated Protein

Ste5 is essential for the yeast mating pheromone response pathway and is thought to function as a scaffold that organizes the components of the mitogen-activated protein kinase (MAPK) cascade. A new method was developed to isolate missense mutations in Ste5 that differentially affect the ability of Ste5 to interact with either of two MAPK cascade constituents, the MEKK (Ste11) and the MEK (Ste7). Mutations that affect association with Ste7 or with Ste11 delineate discrete regions of Ste5 that are critical for each interaction. Co-immunoprecipitation analysis, examining the binding in vitro of Ste5 to Ste11, Ste7, Ste4 (G protein, β subunit), and Fus3 (MAPK), confirmed that each mutation specifically affects the interaction of Ste5 with only one protein. When expressed in a ste5Δ cell, mutant Ste5 proteins that are defective in their ability to interact with either Ste11 or Ste7 result in a markedly reduced mating proficiency. One mutation that clearly weakened (but did not eliminate) interaction of Ste5 with Ste7 permitted mating at wild-type efficiency, indicating that an efficacious signal is generated even when Ste5 associates with only a small fraction of (or only transiently with) Ste7. Ste5 mutants defective in association with Ste11 or Ste7 showed strong interallelic complementation when co-expressed, suggesting that the functional form of Ste5 in vivo is an oligomer.

scholarly journals In silico study of SARS-CoV-2 Nucleocapsid Protein-Protein Interactions and Potential Candidates for their Stabilization

2020 ◽  
Author(s):  
Martin Lavecchia ◽  
Julian Fernandez
Keyword(s):  
Protein Interactions ◽  
Nucleocapsid Protein ◽  
Drug Repurposing ◽  
Structural Motif ◽  
Protein Protein Interactions ◽  
Health Crisis ◽  
N Protein ◽  
Worldwide Distribution ◽  
Novel Coronavirus

The outbreak of the novel coronavirus SARS-CoV-2, the causative agent of COVID-19, has caused a global health crisis. Unfortunately, only a few treatments have proved to be effective, and their worldwide distribution remains as a challenge. Due to the urgency of the situation, drug repurposing remains as the fastest way to identify possible therapeutic options. Recent studies have shown that the stabilization of non-native Protein-Protein Interactions (PPIs) of the nucleocapsid protein of MERS coronavirus is a valid strategy to inhibit viral replication, but no study up to date has been done in SARS-CoV-2. In this work, a novel protocol for the discovery of PPIs stabilizers is presented and applied to SARS-CoV-2 N protein with a drug repurposing approach. This enabled us to identify that catechin, a structural motif present in widely distributed natural products, might be a privileged scaffold for this type of stabilization. Since many of the compounds presented in this work are generally considered nutraceuticals and have also been exhaustively studied, even though some of them contain PAINS substructures, could be good candidates for the SARS-CoV-2 nucleocapsid inhibition and be considered for further in vitro testing against COVID-19.

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.

Neural network dysfunction in bipolar depression: clues from the efficacy of lamotrigine

2009 ◽  
Vol 37 (5) ◽  
pp. 1080-1084 ◽  
Author(s):  
Charles H. Large ◽  
Elena Di Daniel ◽  
Xingbao Li ◽  
Mark S. George
Keyword(s):  
Bipolar Disorder ◽  
Valproic Acid ◽  
Protein Kinase ◽  
Glycogen Synthase ◽  
Bipolar Depression ◽  
Inhibitory Effect ◽  
Mood Stabilizers ◽  
Mitogen Activated Protein Kinase ◽  
Facilitatory Effect

One strategy to understand bipolar disorder is to study the mechanism of action of mood-stabilizing drugs, such as valproic acid and lithium. This approach has implicated a number of intracellular signalling elements, such as GSK3β (glycogen synthase kinase 3β), ERK (extracellular-signal-regulated kinase)/MAPK (mitogen-activated protein kinase) or protein kinase C. However, lamotrigine does not seem to modulate any of these targets, which is intriguing given that its profile in the clinic differs from that of valproic acid or lithium, with greater efficacy to prevent episodes of depression than mania. The primary target of lamotrigine is the voltage-gated sodium channel, but it is unclear why inhibition of these channels might confer antidepressant efficacy. In healthy volunteers, we found that lamotrigine had a facilitatory effect on the BOLD (blood-oxygen-level-dependent) response to TMS (transcranial magnetic stimulation) of the prefrontal cortex. This effect was in contrast with an inhibitory effect of lamotrigine when TMS was applied over the motor cortex. In a follow-up study, a similar prefrontal specific facilitatory effect was observed in a larger cohort of healthy subjects, whereas valproic acid inhibited motor and prefrontal cortical TMS-induced BOLD response. In vitro, we found that lamotrigine (3–10 μM) enhanced the power of gamma frequency network oscillations induced by kainic acid in the rat hippocampus, an effect that was not observed with valproic acid (100 μM). These data suggest that lamotrigine has a positive effect on corticolimbic network function that may differentiate it from other mood stabilizers. The results are also consistent with the notion of corticolimbic network dysfunction in bipolar disorder.

scholarly journals Role for the Ran Binding Protein, Mog1p, in Saccharomyces cerevisiae SLN1-SKN7 Signal Transduction

2004 ◽  
Vol 3 (6) ◽  
pp. 1544-1556 ◽  
Author(s):  
Jade Mei-Yeh Lu ◽  
Robert J. Deschenes ◽  
Jan S. Fassler
Keyword(s):  
Signal Transduction ◽  
Transcription Factor ◽  
Osmotic Stress ◽  
Kinase Activity ◽  
Mitogen Activated Protein Kinase ◽  
Osmotic Response ◽  
Mitogen Activated Protein ◽  
Kinase Pathway

ABSTRACT Yeast Sln1p is an osmotic stress sensor with histidine kinase activity. Modulation of Sln1 kinase activity in response to changes in the osmotic environment regulates the activity of the osmotic response mitogen-activated protein kinase pathway and the activity of the Skn7p transcription factor, both important for adaptation to changing osmotic stress conditions. Many aspects of Sln1 function, such as how kinase activity is regulated to allow a rapid response to the continually changing osmotic environment, are not understood. To gain insight into Sln1p function, we conducted a two-hybrid screen to identify interactors. Mog1p, a protein that interacts with the yeast Ran1 homolog, Gsp1p, was identified in this screen. The interaction with Mog1p was characterized in vitro, and its importance was assessed in vivo. mog1 mutants exhibit defects in SLN1-SKN7 signal transduction and mislocalization of the Skn7p transcription factor. The requirement for Mog1p in normal localization of Skn7p to the nucleus does not fully account for the mog1-related defects in SLN1-SKN7 signal transduction, raising the possibility that Mog1p may play a role in Skn7 binding and activation of osmotic response genes.

The Effect of Wnt Family Member 5a Gene Silencing on the Proliferation of Achondroplasia Using a DNAzymes-CoOOH Nanocomposite

2021 ◽  
Vol 17 (7) ◽  
pp. 1426-1434
Author(s):  
Hairui Xie ◽  
Lili Zhou ◽  
Zhijiang Chen ◽  
Hong Zhao
Keyword(s):  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Family Member ◽  
Interaction Analysis ◽  
Mitogen Activated Protein Kinase ◽  
Mitogen Activated Protein ◽  
Endoplasmic Reticulum Stress Pathway ◽  
Protein Kinase Signaling ◽  
Kinase Signaling Pathway

Achondroplasia is a kind of congenital dysplasia due to the defect of endochondral ossification. Achondroplasia is considered to be a protein folding disease leading to endoplasmic reticulum stress. Endoplasmic reticulum stress may lead to disease by affecting the function and survival state of chondrocytes, but the specific mechanism requires further study. In this study, bioinformatics methods, online database mining, screening of differentially expressed genes for pathway enrichment, and interaction analysis were conducted to detect the Wnt family member 5a (Wnt5a) gene. Additionally, we designed a novel DNAzymes-based nanocomposite that can simultaneously silence Wnt5a genes in chondrocytes. The nanocomposite was composed of amino-functionalized cobalt oxyhydroxide nanoflakes modified by DNAzymes that target the Wnt5a gene. Further, we conducted in vitro experiments to verify that Wnt5a can mediate the mitogen-activated protein kinase signaling pathway through the endoplasmic reticulum stress pathway to affect the proliferation of chondrocytes.

Far1 and Fus3 link the mating pheromone signal transduction pathway to three G1-phase Cdc28 kinase complexes

1993 ◽  
Vol 13 (9) ◽  
pp. 5659-5669 ◽  
Author(s):  
M Tyers ◽  
B Futcher
Keyword(s):  
Signal Transduction ◽  
Protein Kinase ◽  
Signal Transduction Pathway ◽  
Mitogen Activated Protein Kinase ◽  
G1 Phase ◽  
Transduction Pathway ◽  
Yeast Saccharomyces Cerevisiae ◽  
Alpha Factor ◽  
Mitogen Activated Protein

In the yeast Saccharomyces cerevisiae, the Cdc28 protein kinase controls commitment to cell division at Start, but no biologically relevant G1-phase substrates have been identified. We have studied the kinase complexes formed between Cdc28 and each of the G1 cyclins Cln1, Cln2, and Cln3. Each complex has a specific array of coprecipitated in vitro substrates. We identify one of these as Far1, a protein required for pheromone-induced arrest at Start. Treatment with alpha-factor induces a preferential association and/or phosphorylation of Far1 by the Cln1, Cln2, and Cln3 kinase complexes. This induced interaction depends upon the Fus3 protein kinase, a mitogen-activated protein kinase homolog that functions near the bottom of the alpha-factor signal transduction pathway. Thus, we trace a path through which a mitogen-activated protein kinase regulates a Cdc2 kinase.

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