Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P05412 (c-Jun)
 11,453 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have reported previously that activation of human umbilical vein endothelial cells (HUVECs) through CD40, using a recombinant soluble form of trimerized CD40 ligand, leads to induction of E-selectin, vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1). Here, we compare the effects of CD40 ligand with those of tumor necrosis factor (TNF) and interleukin 1 (IL-1). All three ligands induce transient increases in E-selectin (peak 4 h) and VCAM-1 (peak 8-24 h), as well as sustained increases in ICAM-1 (plateau 24 h). Quantitatively, TNF is more potent than IL-1, which is much more potent than CD40 ligand. The same hierarchy is observed for transcriptional activation of an E-selectin promoter reporter gene construct in transiently transfected HUVECs. TNF and CD40 ligand each induced activation of the transcription factors NF-kappa B, IRF-1, and ATF-2/c-Jun, measured by electrophoretic mobility shift assays, but this response appeared quantitatively similar. All three agents transiently (peak 30 min) activated Jun NH2-terminal kinase (JNK), which has been implicated in transcription of E-selectin through its actions on ATF-2/c-Jun. Activation of JNK again showed a hierarchy of potency (TNF > IL-1 >> CD40 ligand), although the time course of induction was similar for all three agents. After 44 h of pretreatment, TNF, IL-1, and CD40 ligand each display homologous desensitization for reinduction of surface expression of E-selectin. A similar pattern of homologous desensitization for reactivation of JNK was observed. We conclude that TNF, IL-1, and CD40 ligand all activate similar responses in ECs, and that homologous desensitization of JNK may explain the inability of individual cytokines to reinduce E-selectin expression.
 ...
PMID:Activation and homologous desensitization of human endothelial cells by CD40 ligand, tumor necrosis factor, and interleukin 1. 869 Nov 31

The Interferon Regulatory Factors (IRFS) play an important role in the transcriptional control of growth regulatory and immunoregulatory genes. The inducibility and availability of IRF-1 and IRF-2 are influenced by external stimuli, such as virus infection or interferon treatment. In the present study, we sought to examine the potential modulatory role of phosphorylation on IRF-1 transcriptional activity. During the purification of IRF recombinant proteins, a kinase activity copurified with IRF-1 (and IRF-2) from baculovirus infected Sf9 insect cell extracts, but not from E. coli extracts. The kinase activity was also identified in Jurkat T cells, specifically interacted with IRF proteins in GST affinity chromatography, and phosphorylated IRF-1 with high specificity in vitro. Using an in gel kinase assay with recombinant IRF-1 as substrate, two molecular weight forms of the kinase (43 and 38 kDa) were identified. Biochemical criteria identified the kinase activity as the alpha catalytic subunit of casein kinase II (CKII). Furthermore, far western analysis of protein-protein interactions demonstrated that casein kinase II directly interacted with IRF-1 protein. Deletion mutation analysis of IRF-1 revealed that IRF-1 was phosphorylated at two clustered sites, one located between amino acids 138-150, the other in the C-terminal acidic activation domain between amino acids 219-231. Cotransfection studies comparing wild type and point mutated forms of IRF-1 demonstrated that mutations of the four phosphoaceptor residues in the C-terminal transactivation domain, significantly decreased transactivation by IRF-1, indicating that casein kinase II may be involved in the regulation of IRF-1 function. Strikingly, the casein kinase II clusters in IRF-1 resemble the sites identified in the C-terminal PEST domain of IkappaBalpha. The present experiments, together with previously published studies with IkappaBalpha, c-Jun and other proteins, indicate a broad role for casein kinase II phosphorylation in the regulation of transcription factor activity.
 ...
PMID:A role for casein kinase II phosphorylation in the regulation of IRF-1 transcriptional activity. 1009 6

The interferon regulatory factor 1 (IRF-1) acts as a transcriptional inducer of the interferon beta (IFN-beta) gene and interferon-stimulated genes. Here we report that IRF-1-mediated IFN-beta induction depends on NFkappaB activity. IRF-1 by itself initiates NFkappaB activation by inducing a reduction in cellular MAD3/IkappaBalpha, an inhibitor of NFkappaB. After nuclear translocation, NFkappaB synergizes with IRF-1 on the cis-elements positive regulatory domain (PRD)II and PRDI/III to induce transcription of the IFN-beta gene. In contrast with IFN-beta transcription induced by dsRNA or virus, c-Jun/ATF-2 binding to PRDIV is not involved. Recombinant MAD3/IkappaBalpha is phosphorylated in vitro by extracts from IRF-1-expressing cells. IRF-1-dependent MAD3/IkappaBalpha degradation is not detectable in cells expressing a dominant negative mutant of the protein kinase PKR, suggesting that PKR mediates MAD3/IkappaBalpha degradation.
 ...
PMID:NFkappaB activation is required for interferon regulatory factor-1-mediated interferon beta induction. 1021 68

Interferon-tau (IFNtau) is produced by the trophectoderm of ruminant ungulates and its gene transactivation in vitro has so far been achieved only in human choriocarcinoma cells, JAR and JEG3. To examine if ovine IFNtau gene transactivation could be induced in cells other than JAR or JEG3 cells and its activation could be aided by the expression of a protooncogene(s), a transient transfection system was developed with the upstream region of ovine IFNtau gene that had been inserted into the chloramphenicol acetyltransferase (CAT) reporter plasmid (IFNtau-CAT). The effect of a protein kinase C (PKC) activator, phorbol 12-myristate 13-acetate (PMA), on IFNtau-CAT transcriptional activity was examined in JEG3, human embryonic kidney (293), HeLa and Vero cells. Upon transfection and PMA treatment, ovine IFNtau gene was transactivated in two unrelated cell lines, JEG3 and 293 cells. Since IFNtau-CAT was not induced in HeLa or Vero cells, HeLa and JEG3 cells were further examined for their ability to support IFNtau-CAT transactivation in a co-transfection system. While the expression of c-myc, interferon regulatory factor 1 or 2 (IRF-1 or IRF-2) was not effective, CAT activity was strongly enhanced in both JEG3 and HeLa cells with the co-transfection of c-Jun or c-Jun plus c-Fos. These data suggest that ovine IFNtau gene transcription induced by PMA is not specific for trophoblast cells and a protooncogene, c-jun, is a downstream effector of PMA activated nuclear factors in its signal transduction cascade resulting in IFNtau gene transactivaion.
 ...
PMID:Effects of PMA and transcription factors on ovine interferon-tau transactivation in various cell lines. 1050 90

Vasoactive intestinal peptide (VIP) and the structurally related neuropeptide pituitary adenylate cyclase activating polypeptide (PACAP), present in the microenvironment of lymphoid organs, modulate the function of inflammatory cells through specific receptors. VIP and PACAP inhibit the production of pro-inflammatory agents and stimulate the production of anti-inflammatory cytokines in activated macrophages. The effect is mediated through specific receptors and involves shedding of the CD14 lipopolysaccharide (LPS) receptor and the transcriptional regulation of cytokine genes through effects on de novo expression or nuclear translocation of NFkappaB, cAMP-element binding protein (CREB), c-Jun, and interferon regulatory factor 1 (IRF-1). The in vivo administration of VIP/PACAP results in a similar pattern of cytokine modulation which, presumably, mediates the protective effect of VIP/PACAP in a high-endotoxic murine model for septic shock. VIP/PACAP reduce the expression of the costimulatory B7.1/B7.2 molecules and the subsequent stimulatory activity for T helper (Th) cells in stimulated macrophages. In contrast, in unstimulated macrophages, VIP/PACAP induce specific B7.2 expression and promote Th2 cell differentiation. We propose that VIP/PACAP act as endogenous factors that regulate immune homeostasis and that the physiological consequences of VIP/PACAP presence in the immune microenvironment depend on the timing of the neuropeptide release and the activation stage of the neighboring immune cells.
 ...
PMID:Neuropeptides as modulators of macrophage functions. Regulation of cytokine production and antigen presentation by VIP and PACAP. 1134 14

The mechanisms of cellular recognition for virus infection remain poorly understood despite the wealth of information regarding the signaling events and transcriptional responses that ensue. Host cells respond to viral infection through the activation of multiple signaling cascades, including the activation of NF-kappaB, c-Jun/ATF-2 (AP-1), and the interferon regulatory factors (IRFs). Although viral products such as double-stranded RNA (dsRNA) and the processes of viral binding and fusion have been implicated in the activation of NF-kappaB and AP-1, the mechanism(s) of IRF-1, IRF-3, and IRF-7 activation has yet to be fully elucidated. Using recombinant measles virus (MeV) constructs, we now demonstrate that phosphorylation-dependent IRF-3 activation represents a novel cellular detection system that recognizes the MeV nucleocapsid structure. At low multiplicities of infection, IRF-3 activation is dependent on viral transcription, since UV cross-linking and a deficient MeV containing a truncated polymerase L gene failed to induce IRF-3 phosphorylation. Expression of the MeV nucleocapsid (N) protein, without the requirement for any additional viral proteins or the generation of dsRNA, was sufficient for IRF-3 activation. In addition, the nucleocapsid protein was found to associate with both IRF-3 and the IRF-3 virus-activated kinase, suggesting that it may aid in the colocalization of the kinase and the substrate. Altogether, this study suggests that IRF-3 recognizes nucleocapsid structures during the course of an MeV infection and triggers the induction of interferon production.
 ...
PMID:Recognition of the measles virus nucleocapsid as a mechanism of IRF-3 activation. 1190 5

The structurally related neuropeptides VIP and PACAP are released within the lymphoid organs following antigenic stimulation, and modulate the function of inflammatory cells through specific receptors. In activated macrophages, VIP and PACAP inhibit the production of pro-inflammatory agents (cytokines, chemokines, and nitric oxide), and stimulate the production of the anti-inflammatory cytokine IL-10. These events are mediated through the VIP/PACAP effects on de novo expression or nuclear translocation of several transcription factors, i.e., NFkappaB, CREB, c-Jun, JunB, and IRF-1. The in vivo administration of VIP/PACAP results in a similar pattern of cytokine and chemokine modulation, which presumably mediates the protective effect of VIP/PACAP in septic shock. In addition, VIP/PACAP reduce the expression of the co-stimulatory molecules B7.1/B7.2, and the subsequent stimulatory activity of macrophages for T-helper cells. In T-cells expressing specific VIP/PACAP receptors, VIP and PACAP inhibit the expression of FasL through effects on NFkappaB, NFAT, and Egr2/3. The reduction of FasL expression has several biological consequences: inhibition of antigen-induced cell death in CD4 T-cells, inhibition of the FasL-mediated cytotoxicity of CD8 and CD4 effectors against direct and bystander targets, and promotion of long-term memory Th2 cells, through a positive effect on the survival of Th2, but not Th1, effectors. The various biological effects of VIP and PACAP are discussed within the range of a general anti-inflammatory model.
 ...
PMID:Vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating polypeptide (PACAP) as modulators of both innate and adaptive immunity. 1209 Apr 63

The structurally related neuropeptides vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase activating polypeptide (PACAP) are released within the lymphoid organs following antigenic stimulation, and modulate the function of inflammatory cells through specific receptors. In activated macrophages, VIP and PACAP inhibit the expression at both mRNA and protein level of pro-inflammatory cytokines and chemokines, through effects on de novo expression or nuclear translocation of a number of transcription factors, i.e. NFkB, CREB, c-Jun, JunB, and IRF-1. In addition, VIP and PACAP promote Th2-type, and inhibit Th1-type responses in vivo and in vitro, through several mechanisms, including preferential survival of Th2 effectors and subsequent generation of Th2 memory cells. The function of VIP/PACAP as "macrophage deactivating factors" appears to be responsible for their protective effect in vivo in models of septic shock. Both deactivation of macrophages and inhibition of Th1-type responses appear to be responsible for the beneficial effect of VIP/PACAP in models of Th1-type autoimmune diseases such as rheumatoid arthritis.
 ...
PMID:The neuropeptides VIP/PACAP and T cells: inhibitors or activators? 1267 66

The interferon-beta promoter has been studied extensively as a model system for combinatorial transcriptional regulation. In virus-infected cells the transcription factors ATF-2, c-Jun, interferon regulatory factor (IRF)-3, IRF-7 and NF-kappaB, and the coactivators p300/CBP play critical roles in the activation of this and other promoters. It remains unclear, however, why most other combinations of AP-1, IRF and Rel proteins fail to activate the interferon-beta gene. Here we have explored how different IRFs may cooperate with other factors to activate transcription. First we showed in undifferentiated embryonic carcinoma cells that ectopic expression of either IRF-3 or IRF-7, but not IRF-1, was sufficient to allow virus-dependent activation of the interferon-beta promoter. Moreover, the activity of IRF-3 and IRF-7 was strongly affected by promoter context, with IRF-7 preferentially being recruited to the natural interferon-beta promoter. We fully reconstituted activation of this promoter in insect cells. Maximal synergy required IRF-3 and IRF-7 but not IRF-1, and was strongly dependent on the presence of p300/CBP, even when these coactivators only modestly affected the activity of each factor by itself. These results suggest that specificity in activation of the interferon-beta gene depends on a unique promoter context and on the role played by coactivators as architectural factors.
 ...
PMID:Mechanism for transcriptional synergy between interferon regulatory factor (IRF)-3 and IRF-7 in activation of the interferon-beta gene promoter. 1535 47

(5R)-5-Hydroxytriptolide (LLDT-8) is a novel analog of triptolide that has antiarthritic, hepatoprotective, and antiallogenic transplantation-rejective effects. In the present study, we report that LLDT-8 inhibited nitric oxide (NO) production and inducible nitric-oxide synthase (iNOS) expression in macrophages. LLDT-8 significantly attenuated NO production, in a dose-dependent manner, in primary peritoneal macrophages and a macrophage cell line of Raw 264.7 cells following stimulation with interferon (IFN)-gamma, lipopolysaccharide (LPS), and IFN-gamma plus LPS. It also reduced the production of tumor necrosis factor-alpha from LPS-stimulated Raw 264.7 cells. To further elucidate the mechanism responsible for the inhibition of NO, we examined the effect of LLDT-8 on IFN-gamma and LPS-induced iNOS expression. Indeed, LLDT-8 prevented NO generation by inhibiting iNOS expression at mRNA level and protein level, rather than by interfering its enzymatic activity. In IFN-gamma-stimulated Raw 264.7 cells, LLDT-8 suppressed the gene transcription of signal transducer and activator of transcription 1alpha and interferon regulatory factor (IRF)-1, but it displayed no apparent effect on IFN-gamma receptor level on cell surface. After LPS challenge, LLDT-8 further abrogated the expression of LPS receptor complex, including CD14, Toll-like receptor 4, and myeloid differentiation protein-2; decreased the LPS-induced phosphorylation of stress-activated protein kinase/c-Jun NH(2)-terminal kinase, extracellular signal-regulated kinase 1/2, and p38 mitogen-activated protein kinase (MAPK); retarded the degradation of IkappaBalpha; and ameliorated the DNA binding activity of nuclear factor-kappaB (NF-kappaB) to nuclear proteins that accounts for transcriptional regulation of iNOS. Taken together, these results suggest that LLDT-8 reduces NO production and iNOS expression by inhibiting IFN-gamma-triggered IRF-1 expression and LPS-triggered MAPK phosphorylation and NF-kappaB activation.
 ...
PMID:Inhibition of inducible nitric-oxide synthase expression by (5R)-5-hydroxytriptolide in interferon-gamma- and bacterial lipopolysaccharide-stimulated macrophages. 1616 70


1 2 Next >>