scholarly journals Severe Acute Respiratory Syndrome Coronavirus 7a Accessory Protein Is a Viral Structural Protein

2006 ◽  
Vol 80 (15) ◽  
pp. 7287-7294 ◽  
Author(s):  
Cheng Huang ◽  
Naoto Ito ◽  
Chien-Te K. Tseng ◽  
Shinji Makino
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Biological Activities ◽  
Protein Translation ◽  
Host Protein ◽  
Mitogen Activated Protein Kinase ◽  
Accessory Protein ◽  
Structural Protein ◽  
S Protein ◽  
Mitogen Activated Protein ◽  
Protein Incorporation

ABSTRACT Severe acute respiratory syndrome coronavirus (SCoV) 7a protein is one of the viral accessory proteins. In expressing cells, 7a protein exhibits a variety of biological activities, including induction of apoptosis, activation of the mitogen-activated protein kinase signaling pathway, inhibition of host protein translation, and suppression of cell growth progression. Analysis of SCoV particles that were purified by either sucrose gradient equilibrium centrifugation or a virus capture assay, in which intact SCoV particles were specifically immunoprecipitated by anti-S protein monoclonal antibody, demonstrated that 7a protein was associated with purified SCoV particles. Coexpression of 7a protein with SCoV S, M, N, and E proteins resulted in production of virus-like particles (VLPs) carrying 7a protein, while 7a protein was not released from cells expressing 7a protein alone. Although interaction between 7a protein and another SCoV accessory protein, 3a, has been reported, 3a protein was dispensable for assembly of 7a protein into VLPs. S protein was not required for the 7a protein incorporation into VLPs, and yet 7a protein interacted with S protein in coexpressing cells. These data established that, in addition to 3a protein, 7a protein was a SCoV accessory protein identified as a SCoV structural protein.

scholarly journals Paeoniflorin and Albiflorin Attenuate Neuropathic Pain via MAPK Pathway in Chronic Constriction Injury Rats

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Jianyu Zhou ◽  
Linyuan Wang ◽  
Jingxia Wang ◽  
Chun Wang ◽  
Zhihui Yang ◽  
...  
Keyword(s):  
Neuropathic Pain ◽  
Chronic Constriction Injury ◽  
Mapk Pathway ◽  
Biological Activities ◽  
Neuroprotective Effect ◽  
Interleukin 1 ◽  
Underlying Mechanism ◽  
Mitogen Activated Protein Kinase ◽  
Mitogen Activated Protein ◽  
Necrosis Factor

Neuropathic pain remains as the most frequent cause of suffering and disability around the world. The isomers paeoniflorin (PF) and albiflorin (AF) are major constituents extracted from the roots ofPaeonia (P.) lactifloraPall. Neuroprotective effect of PF has been demonstrated in animal models of neuropathologies. However, only a few studies are related to the biological activities of AF and no report has been published on analgesic properties of AF about neuropathic pain to date. The aim of this study was to compare the effects of AF and PF against CCI-induced neuropathic pain in rat and explore the underlying mechanism. We had found that both PF and AF could inhibit the activation of p38 mitogen-activated protein kinase (p38 MAPK) pathway in spinal microglia and subsequent upregulated proinflammatory cytokines (interleukin-1β(IL-1β) and tumor necrosis factor-α(TNF-α)). AF further displayed remarkable effects on inhibiting the activation of astrocytes, suppressing the overelevated expression of phosphorylation of c-Jun N-terminal kinases (p-JNK) in astrocytes, and decreasing the content of chemokine CXCL1 in the spinal cord. These results suggest that both PF and AF are potential therapeutic agents for neuropathic pain, which merit further investigation.

Angiotensin II regulates phosphorylation of translation elongation factor-2 in cardiac myocytes

2001 ◽  
Vol 281 (1) ◽  
pp. H161-H167 ◽  
Author(s):  
Allen D. Everett ◽  
Tamara D. Stoops ◽  
Angus C. Nairn ◽  
David Brautigan
Keyword(s):  
Protein Synthesis ◽  
Angiotensin Ii ◽  
Cardiac Myocytes ◽  
Elongation Factor ◽  
Protein Translation ◽  
Mitogen Activated Protein Kinase ◽  
Ang Ii ◽  
Elongation Factor 2 ◽  
Mitogen Activated Protein ◽  
20 Nm

Increased protein synthesis is the cardinal feature of cardiac hypertrophy. We have studied angiotensin II (ANG II)-dependent regulation of eukaryotic elongation factor-2 (eEF-2), an essential component of protein translation required for polypeptide elongation, in rat neonatal cardiac myocytes. eEF2 is fully active in its dephosphorylated state and is inhibited following phosphorylation by eEF2 kinase. ANG II treatment (10−10–10−7 M) for 30 min produced an AT1 receptor-specific and concentration- and time-dependent reduction in the phosphorylation of eEF-2. Protein phosphatase 2A (PP2A) inhibitors okadaic acid and fostriecin, but not the PP2B inhibitor FK506, attenuated ANG II-dependent dephosphorylation of eEF-2. ANG II activated mitogen-activated protein kinase, (MAPK) within 10 min of treatment, and blockade of MAPK activation with PD-98059 (1–20 nM) inhibited eEF-2 dephosphorylation. The effect of ANG II on eEF-2 dephosphorylation was also blocked by LY-29004 (1–20 nM), suggesting a role for phosphoinositide 3-kinase, but the mammalian target rapamycin inhibitor rapamycin (10–100 nM) had no effect. Together these results suggest that the ANG II-dependent increase in protein synthesis includes activation of eEF-2 via dephosphorylation by PP2A by a process that involves both PI3K and MAPK.

scholarly journals Mos in the Oocyte: How to Use MAPK Independently of Growth Factors and Transcription to Control Meiotic Divisions

2011 ◽  
Vol 2011 ◽  
pp. 1-15 ◽  
Author(s):  
Aude Dupré ◽  
Olivier Haccard ◽  
Catherine Jessus
Keyword(s):  
Growth Factors ◽  
Transcriptional Activation ◽  
Biological Activities ◽  
Growth Factor Receptor ◽  
Cell Types ◽  
Mitogen Activated Protein Kinase ◽  
Specific Cell ◽  
Cell Type ◽  
Specific Cell Type ◽  
Mitogen Activated Protein

In many cell types, the mitogen-activated protein kinase (MAPK) also named extracellular signal-regulated kinase (ERK) is activated in response to a variety of extracellular growth factor-receptor interactions and leads to the transcriptional activation of immediate early genes, hereby influencing a number of tissue-specific biological activities, as cell proliferation, survival and differentiation. In one specific cell type however, the female germ cell, MAPK does not follow this canonical scheme. In oocytes, MAPK is activated independently of growth factors and tyrosine kinase receptors, acts independently of transcriptional regulation, plays a crucial role in controlling meiotic divisions, and is under the control of a peculiar upstream regulator, the kinase Mos. Mos was originally identified as the transforming gene of Moloney murine sarcoma virus and its cellular homologue was the first proto-oncogene to be molecularly cloned. What could be the specific roles of Mos that render it necessary for meiosis? Which unique functions could explain the evolutionary cost to have selected one gene to only serve for few hours in one very specific cell type? This review discusses the original features of MAPK activation by Mos and the roles of this module in oocytes.

scholarly journals Embelin as a Novel Inhibitor of PKC in the Prevention of Platelet Activation and Thrombus Formation

2019 ◽  
Vol 8 (10) ◽  
pp. 1724 ◽  
Author(s):  
Jiun Yi Li ◽  
Ray Jade Chen ◽  
Li Ting Huang ◽  
Tzu Yin Lee ◽  
Wan Jung Lu ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Therapeutic Potential ◽  
Thrombus Formation ◽  
Biological Activities ◽  
Mitogen Activated Protein Kinase ◽  
Antitumor Effects ◽  
Pkc Inhibitor ◽  
Downstream Signaling ◽  
Embelia Ribes ◽  
Mitogen Activated Protein

Embelin is a quinone derivative and found in the fruits of Embelia ribes Burm.f. Embelin has been identified as a small molecular inhibitor of X-chromosome-linked inhibitor of apoptosis proteins, and has multiple biological activities, including antioxidation, anti-inflammation, and antitumor effects. However, the effect of embelin in platelets remains unclear. Thus, this study investigated the antiplatelet mechanism of embelin. Our data revealed that embelin could inhibit platelet aggregation induced by various agonists, including the protein kinase C (PKC) activator phorbol 12,13-dibutyrate (PDBu). Embelin, as well as the PKC inhibitor Ro 31-8220, markedly reduced PDBu-mediated phosphorylation of the PKC substrate, suggesting that embelin may be a PKC inhibitor for platelets. Embelin could block PKC downstream signaling and events, including the inhibition of protein kinase B and mitogen-activated protein kinase activation, granule release, and glycoprotein IIbIIIa activation. Moreover, embelin could delay thrombus formation in the mesenteric microvessels of mice, but did not significantly affect the tail bleeding time. In conclusion, we demonstrated that embelin is a PKC inhibitor and possesses antiplatelet and antithrombotic effects. The further analysis is necessary to more accurately determine clinical therapeutic potential of embelin in all clinical thromboembolic events with disturbance of thrombocyte function.

scholarly journals Screening of Duck Tembusu Virus NS3 Interacting Host Proteins and Identification of Its Specific Interplay Domains

Viruses ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 740 ◽  
Author(s):  
Yawen Wang ◽  
Shuai Zhang ◽  
Yi Tang ◽  
Youxiang Diao
Keyword(s):  
Mitogen Activated Protein Kinase ◽  
Structural Protein ◽  
Host Proteins ◽  
Host Immune Responses ◽  
Yeast Two Hybrid System ◽  
Duck Tembusu Virus ◽  
Ns3 Protein ◽  
Mitogen Activated Protein ◽  
Tembusu Virus ◽  
Information Database

NS3 protein is a member of the non-structural protein of duck Tembusu virus (DTMUV), which contains three domains, each of which has serine protease, nucleotide triphosphatase, and RNA helicase activities, respectively. It performs a variety of biological functions that are involved in the regulation of the viral life cycle and host immune response. Based on the yeast two-hybrid system, we successfully transformed pGBKT7-NS3 bait plasmid into Y2H Gold, tested it to prove that it has no self-activation and toxicity, and then hybridized it with the prey yeast strain of the duck embryo fibroblast cDNA library for screening. After high-stringency selection, positive alignment with the National Center for Biotechnology Information database revealed nine potential interactive proteins: MGST1, ERCC4, WIF1, WDR75, ACBD3, PRDX1, RPS7, ND5, and LDHA. The most interesting one (PRDX1) was selected to be verified with full-length NS3 protein and its three domains S7/DEXDc/HELICc using yeast regressive verification and GST Pull-Down assay. It denoted that PRDX1 does indeed interact with HELICc domains of NS3. NS3 is involved in the RNA uncoiling process of viral replication, which may cause mitochondrial overload to create oxidative stress (OS) during DTMUV attack. We deduced that the HELICc domain binding partner PRDX1, which regulates the p38/mitogen-activated protein kinase pathway (p38/MAPK) to avert OS, causing apoptosis, making it possible for viruses to escape host immune responses.

scholarly journals The tRNA Modification Complex Elongator Regulates the Cdc42-Dependent Mitogen-Activated Protein Kinase Pathway That Controls Filamentous Growth in Yeast

2009 ◽  
Vol 8 (9) ◽  
pp. 1362-1372 ◽  
Author(s):  
Ummi Abdullah ◽  
Paul J. Cullen
Keyword(s):  
Protein Kinase ◽  
Mapk Pathway ◽  
Protein Translation ◽  
Filamentous Growth ◽  
Cell Polarization ◽  
Mitogen Activated Protein Kinase ◽  
Global Changes ◽  
Trna Modification ◽  
Mitogen Activated Protein ◽  
Growth Pathway

ABSTRACT Signal transduction pathways control multiple aspects of cellular behavior, including global changes to the cell cycle, cell polarity, and gene expression, which can result in the formation of a new cell type. In the budding yeast Saccharomyces cerevisiae, the mitogen-activated protein kinase (MAPK) pathway that controls filamentous growth induces a dimorphic foraging response under nutrient-limiting conditions. How nutritional cues feed into MAPK activation remains an open question. Here we report a functional connection between the elongator tRNA modification complex (ELP genes) and activity of the filamentous growth pathway. Elongator was required for filamentous growth pathway signaling, and elp mutants were defective for invasive growth, cell polarization, and MAPK-dependent mat formation. Genetic suppression analysis showed that elongator functions at the level of Msb2p, the signaling mucin that operates at the head of the pathway, which led to the finding that elongator regulates the starvation-dependent expression of the MSB2 gene. The Elp complex was not required for activation of related pathways (pheromone response or high osmolarity glycerol response) that share components with the filamentous growth pathway. Because protein translation provides a rough metric of cellular nutritional status, elongator may convey nutritional information to the filamentous growth pathway at the level of MSB2 expression.

Distinct roles for extracellular-signal-regulated protein kinase (ERK) mitogen-activated protein kinases and phosphatidylinositol 3-kinase in the regulation of Mcl-1 synthesis

2001 ◽  
Vol 356 (2) ◽  
pp. 473-480 ◽  
Author(s):  
Kathryn M. SCHUBERT ◽  
Vincent DURONIO
Keyword(s):  
Protein Kinase ◽  
Mapk Pathway ◽  
Family Members ◽  
Protein Translation ◽  
Mitogen Activated Protein Kinase ◽  
Mrna Levels ◽  
Phosphatidylinositol 3 Kinase ◽  
Extracellular Signal ◽  
Mitogen Activated Protein ◽  
Phosphatidylinositol 3

Alterations in the expression of various Bcl-2 family members may act as one means by which a cell's survival may be regulated. The mechanism by which cytokines regulate expression of Bcl-2 family members was examined in the haemopoietic cell line TF-1. Cytokine-induced Mcl-1 protein expression was shown to be controlled through a pathway dependent upon phosphatidylinositol 3-kinase (PI 3-kinase). The cytokine-induced increase in mRNA transcription was not dependent upon PI 3-kinase, thus dissociating the immediate-early transcription factors responsible for Mcl-1 transcription from the PI 3-kinase signalling pathway. In contrast, Mcl-1 mRNA levels were dependent upon MEK [mitogen-activated protein kinase (MAPK)/extracellular-signal-regulated protein kinase kinase] activation, suggesting a role for the Ras/MEK/MAPK pathway in Mcl-1 transcription. Activation of PI 3-kinase was shown to be necessary to stimulate Mcl-1 protein translation. This was not due to any effect on prolonging the half-life of the protein. Finally, the lipid second messenger ceramide was shown to cause a reduction in Mcl-1 protein translation, probably via its ability to inhibit protein kinase B activation, providing further clues regarding the death-inducing effect of this lipid.

scholarly journals Role of Muramyl Dipeptide in Lipopolysaccharide-Mediated Biological Activity and Osteoclast Activity

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Hideki Kitaura ◽  
Masahiko Ishida ◽  
Keisuke Kimura ◽  
Haruki Sugisawa ◽  
Akiko Kishikawa ◽  
...  
Keyword(s):  
Biological Activities ◽  
Muramyl Dipeptide ◽  
Mapk Signaling ◽  
Osteoclast Formation ◽  
Mitogen Activated Protein Kinase ◽  
Immunological Activity ◽  
Mitogen Activated Protein

Lipopolysaccharide (LPS) is an endotoxin and bacterial cell wall component that is capable of inducing inflammation and immunological activity. Muramyl dipeptide (MDP), the minimal essential structural unit responsible for the immunological activity of peptidoglycans, is another inflammation-inducing molecule that is ubiquitously expressed by bacteria. Several studies have shown that inflammation-related biological activities were synergistically induced by interactions between LPS and MDP. MDP synergistically enhances production of proinflammatory cytokines that are induced by LPS exposure. Injection of MDP induces lethal shock in mice challenged with LPS. LPS also induces osteoclast formation and pathological bone resorption; MDP enhances LPS induction of both processes. Furthermore, MDP enhances the LPS-induced receptor activator of NF-κB ligand (RANKL) expression and toll-like receptor 4 (TLR4) expression bothin vivoandin vitro. Additionally, MDP enhances LPS-induced mitogen-activated protein kinase (MAPK) signaling in stromal cells. Taken together, these findings suggest that MDP plays an important role in LPS-induced biological activities. This review discusses the role of MDP in LPS-mediated biological activities, primarily in relation to osteoclastogenesis.

scholarly journals Identification of an Antigenic Determinant on the S2 Domain of the Severe Acute Respiratory Syndrome Coronavirus Spike Glycoprotein Capable of Inducing Neutralizing Antibodies

2004 ◽  
Vol 78 (13) ◽  
pp. 6938-6945 ◽  
Author(s):  
Hong Zhang ◽  
Guangwen Wang ◽  
Jian Li ◽  
Yuchun Nie ◽  
Xuanling Shi ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Antigenic Determinant ◽  
Neutralizing Antibodies ◽  
Antigenic Structure ◽  
Antigenic Determinants ◽  
Structural Protein ◽  
Binding Ability ◽  
S Protein ◽  
Life Threatening ◽  
Carboxyl Terminal

ABSTRACT Severe acute respiratory syndrome (SARS) is a life-threatening disease caused by a newly identified coronavirus (CoV), SARS-CoV. The spike (S) glycoprotein of CoV is the major structural protein responsible for induction of host immune response and virus neutralization by antibodies. Hence, knowledge of neutralization determinants on the S protein is helpful for designing protective vaccines. To analyze the antigenic structure of the SARS-CoV S2 domain, the carboxyl-terminal half of the S protein, we first used sera from convalescent SARS patients to test the antigenicity of 12 overlapping fragments spanning the entire S2 and identified two antigenic determinants (Leu 803 to Ala 828 and Pro 1061 to Ser 1093). To determine whether neutralizing antibodies can be elicited by these two determinants, we immunized animals and found that both of them could induce the S2-specific antisera. In some animals, however, only one determinant (Leu 803 to Ala 828) was able to induce the antisera with the binding ability to the native S protein and the neutralizing activity to the SARS-CoV pseudovirus. This determinant is highly conserved across different SARS-CoV isolates. Identification of a conserved antigenic determinant on the S2 domain of the SARS-CoV S protein, which has the potential for inducing neutralizing antibodies, has implications in the development of effective vaccines against SARS-CoV.

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