Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

NF (nuclear factor)-kappaB is known to be a critical transcription factor in inflammatory responses. We have reported that herbimycin A, a potent Src tyrosine kinase inhibitor, attenuates the NF-kappaB activation triggered by cytokines, bacterial endotoxin, and hydrogen peroxide. Accompanying the suppression by this agent, NF-kappaB-dependent gene expressions, such as cytokine, chemokine, and inducible-type nitric oxide, are specifically inhibited in glial cells. In the present study, we attempted to elucidate the possible target protein for herbimycin A on this pathway. We demonstrate here that herbimycin A preferentially inhibits IKK (IkappaB kinase)beta. Furthermore, substituting alanine for the cysteine at 59 (Cys59) in IKKbeta resulted in the insensitivity to herbimycin A, suggesting that this compound may interact with the Cys59 residue located near the catalytic ATP binding site. Taken together, these results indicate that herbimycin A can be considered a novel candidate for an anti-inflammatory drug agent through its specific inhibition of IKKbeta, which results in prevention of the expression of NF-kappaB-dependent genes implicated in the pathogenesis of inflammatory responses.
Mol Pharmacol 2004 Jun
PMID:Herbimycin A abrogates nuclear factor-kappaB activation by interacting preferentially with the IkappaB kinase beta subunit. 1515 28

IkappaB kinase (IKK), a key regulator of immune and inflammatory responses, is known as an effector kinase mediating activation of the transcription factor NF-kappaB. Whether IKK also participates in other signaling events is not known. Here we show that IKK serves as an essential component of a signaling pathway that involves activation of the Tpl2 kinase and its downstream targets, MEK1 and ERK. Inhibition of IKKbeta in macrophages eliminates Tpl2 activation and ERK phosphorylation induced by lipopolysaccharide and tumor necrosis factor alpha. Using IKK-deficient murine fibroblasts, we further demonstrate that IKKbeta, but not IKKalpha, is required for Tpl2 activation. Moreover, this novel function of IKKbeta appears to involve phosphorylation and degradation of the Tpl2 inhibitor NF-kappaB1/p105. These findings suggest that IKKbeta exerts its immune-regulatory functions by targeting different downstream signaling pathways.
Mol Cell Biol 2004 Jul
PMID:IkappaB kinase is an essential component of the Tpl2 signaling pathway. 1519 57

Signal transduction through the T cell receptor (TCR) and a costimulatory molecule, CD28, results in the stimulation of multiple signaling pathways, leading to the activation of several transcription factors including activator protein-1 (AP-1), nuclear factor of activated T cells (NF-AT), and nuclear factor kappa B (NF-kappaB). The molecular mechanisms by which NF-kappaB is activated by TCR-CD28 have only recently become known. New findings indicate that the adaptor molecules CARMA1 and Bcl10 are essential to the process. Additionally, a critical role for MALT1/paracaspase has been identified. MALT1, CARMA1, and Bcl10 form a tripartite protein complex, in which Bcl10 is thought to facilitate the oligomerization of MALT1 monomers. Overexpression of MALT1, as observed in a subset of lymphoma patients, leads to the potent activation of NF-kappaB, suggesting that MALT1 might stimulate (directly or indirectly) the kinase complex [IKK, inhibitor of NF-kappaB (IkappaB) kinase] responsible for activating cytoplasmic NF-kappaB for translocation into the nucleus. Moreover, the MALT1-CARMA1-Bcl10 complex is responsible for ubiquitination of NEMO, a step that appears to be critical for TCR-induced NF-kappaB activation but not for induction mediated by other stimuli such as TNF or IL-1.
Mol Interv 2004 Jun
PMID:Ubiquitination for activation: new directions in the NF-kappaB roadmap. 1521 Aug 67

Activation of the inducible transcription factor nuclear factor kappaB (NF-kappaB) occurs in cells exposed to oxidative stress, and the serine/threonine kinase protein kinase D (PKD) is critical for signal relay to NF-kappaB. We have recently delineated two coordinated events that control PKD activation in response to oxidative stress: phosphorylation at Tyr463 by the tyrosine kinase Abl, and phosphorylation at the activation loop Ser738/Ser742 by the protein kinase C (PKC) isoform PKCdelta. The result is fully active PKD that controls NF-kappaB activation through the IkappaB kinase (IKK) complex. Here, we investigate the mechanism by which PKD controls IKK/NF-kappaB activation. Resveratrol, a potent antioxidant, blocks both PKD activation and NF-kappaB induction. In particular, resveratrol blocked PKD activation loop phosphorylation and activity, and this was caused by a specific inhibition of the Ser738/Ser742 kinase PKCdelta. On the other hand, resveratrol did not affect Abl kinase activity and had no effect on Tyr463 phosphorylation. Moreover, we show that the mechanism by which resveratrol inhibits NF-kappaB is by blocking the translocation of PKD to the IKK complex, specifically by inhibiting Ser738/Ser742 phosphorylation. We therefore propose that rather than acting as an antioxidant, resveratrol specifically blocks oxidative stress-dependent NF-kappaB activation by interfering with PKD phosphorylation and association with the IKK complex.
Mol Pharmacol 2004 Oct
PMID:Activation loop phosphorylation controls protein kinase D-dependent activation of nuclear factor kappaB. 1522 14

Toll-like receptors (TLRs) recognize conserved products of microbial pathogens to initiate the innate immune response. TLR4 signaling is triggered upon binding of lipopolysaccharides (LPS) from gram-negative bacteria. Using comparative gene expression profiling, we demonstrate a master regulatory role of IkappaB kinase (IKK)/NF-kappaB signaling for immediate-early gene induction after LPS engagement in precursor B cells. IKK/NF-kappaB signaling controls a large panel of gene products associated with signaling and transcriptional activation and repression. Intriguingly, the induction of AP-1 activity by LPS in precursor B cells and primary dendritic cells fully depends on the IKK/NF-kappaB pathway, which promotes expression of several AP-1 family members, including JunB, JunD, and B-ATF. In pre-B cells, AP-1 augments induction of a subset of primary NF-kappaB targets, as shown for chemokine receptor 7 (CCR7) and immunoglobulin kappa light chain. Thus, our data illustrate that NF-kappaB orchestrates immediate-early effects of LPS signaling and controls secondary AP-1 activation to mount an appropriate biological response.
Mol Cell Biol 2004 Jul
PMID:The IkappaB kinase complex and NF-kappaB act as master regulators of lipopolysaccharide-induced gene expression and control subordinate activation of AP-1. 1522 48

Incontinentia Pigmenti (IP) is an X-linked genodermatosis that is lethal for males and present in females with abnormal skin pigmentation and high variable clinical signs, including retinal detachment, anodontia, alopecia, nail dystrophy and nervous system defects. The NF-kappaB essential modulator (NEMO) gene, responsible for IP, encodes the regulatory subunit of the IkappaB kinase (IKK) complex required for nuclear factor kappaB (NF-kappaB) activation. We analyzed the NEMO gene in 122 IP patients and identified mutations in 83 (36 familiar and 47 sporadic cases). The recurrent NEMO exon 4-10 deletion that is the major cause of the disease was present in 73 females (59.8%). In addition 10 point alterations (8.2% of females) were identified: three frameshift, three nonsense, three missense and one in-frame deletion of a single amino acid. We measured the effects of these NEMO point-mutations on NF-kappaB signaling in nemo(-/-) deficient murine pre-B cells. A mutation in the N-terminal domain, required for IKK assembly, reduced but did not abolish NF-kappaB activation following lipopolysaccharide stimulation. Mutations that disrupt the C-terminal domain, required for the recruitment of upstream factors, showed lower or no NF-kappaB activation. A phenotype score based on clinical features of our IP patients was applied for summarizing disease severity. The score did not correlate with mutation type or domain affected indicating that other factors influence the severity of IP. Such a factor is likely to be X-inactivation. Indeed, 64% of our patients have extremely skewed X-inactivation pattern (>/=80 : 20). Overall IP pathogenesis thus depends on a combination of X-inactivation and protein domain that recruit upstream factors and activate NF-kappaB.
Hum Mol Genet 2004 Aug 15
PMID:Molecular analysis of the genetic defect in a large cohort of IP patients and identification of novel NEMO mutations interfering with NF-kappaB activation. 1522 84

Nuclear factor kappaB (NF-kappaB) and activator protein 1 (AP-1) transcription factors regulate many important biological and pathological processes. Activation of NF-kappaB is regulated by the inducible phosphorylation of NF-kappaB inhibitor IkappaB by IkappaB kinase. In contrast, Fos, a key component of AP-1, is primarily transcriptionally regulated by serum responsive factors (SRFs) and ternary complex factors (TCFs). Despite these different regulatory mechanisms, there is an intriguing possibility that NF-kappaB and AP-1 may modulate each other, thus expanding the scope of these two rapidly inducible transcription factors. To determine whether NF-kappaB activity is involved in the regulation of fos expression in response to various stimuli, we analyzed activity of AP-1 and expression of fos, fosB, fra-1, fra-2, jun, junB, and junD, as well as AP-1 downstream target gene VEGF, using MDAPanc-28 and MDAPanc-28/IkappaBalphaM pancreatic tumor cells and wild-type, IKK1-/-, and IKK2-/- murine embryonic fibroblast cells. Our results show that elk-1, a member of TCFs, is one of the NF-kappaB downstream target genes. Inhibition of NF-kappaB activity greatly decreased expression of elk-1. Consequently, the reduced level of activated Elk-1 protein by extracellular signal-regulated kinase impeded constitutive, serum-, and superoxide-inducible c-fos expression. Thus, our study revealed a distinct and essential role of NF-kappaB in participating in the regulation of elk-1, c-fos, and VEGF expression.
Mol Cell Biol 2004 Sep
PMID:NF-kappaB and AP-1 connection: mechanism of NF-kappaB-dependent regulation of AP-1 activity. 1531 85

We investigated the effect of gamma-mangostin purified from the fruit hull of the medicinal plant Garcinia mangostana on spontaneous prostaglandin E(2) (PGE(2)) genase release and inducible cyclooxy-2 (COX-2) gene expression in C6 rat glioma cells. An 18-h treatment with gamma-mangostin potently inhibited spontaneous PGE(2) release in a concentration-dependent manner with the IC(50) value of approximately 2 microM, without affecting the cell viability even at 30 microM. By immunoblotting and reverse-transcription polymerase chain reaction, we showed that gamma-mangostin concentration-dependently inhibited lipopolysaccharide (LPS)-induced expression of COX-2 protein and its mRNA, but not those of constitutive COX-1 cyclooxygenase. Because LPS is known to stimulate inhibitor kappaB (IkappaB) kinase (IKK)-mediated phosphorylation of IkappaB followed by its degradation, which in turn induces nuclear factor (NF)-kappaB nuclear translocation leading to transcriptional activation of COX-2 gene, the effect of gamma-mangostin on the IKK/IkappaB cascade controlling the NF-kappaB activation was examined. An in vitro IKK assay using IKK protein immunoprecipitated from C6 cell extract showed that this compound inhibited IKK activity in a concentration-dependent manner, with the IC(50) value of approximately 10 microM. Consistently gamma-mangostin was also observed to decrease the LPS-induced IkappaB degradation and phosphorylation in a concentration-dependent manner, as assayed by immunoblotting. Furthermore, luciferase reporter assays showed that gamma-mangostin reduced the LPS-inducible activation of NF-kappaB-and human COX-2 gene promoter region-dependent transcription. gamma-Mangostin also inhibited rat carrageenan-induced paw edema. These results suggest that gamma-mangostin directly inhibits IKK activity and thereby prevents COX-2 gene transcription, an NF-kappaB target gene, probably to decrease the inflammatory agent-stimulated PGE(2) production in vivo, and is a new useful lead compound for anti-inflammatory drug development.
Mol Pharmacol 2004 Sep
PMID:gamma-Mangostin inhibits inhibitor-kappaB kinase activity and decreases lipopolysaccharide-induced cyclooxygenase-2 gene expression in C6 rat glioma cells. 1532 59

Intercellular adhesion molecule-1 (ICAM-1) has been implicated in the processes of inflammation and carcinogenesis. Flavonoids, which are polyphenolic compounds with a wide distribution throughout the plant kingdom, have potent anti-inflammatory properties. We investigated the effects of flavonols (kaempferol, quercetin, and myricetin) and flavones (flavone, chrysin, apigenin, luteolin, baicalein, and baicalin) on the tumor necrosis factor-alpha (TNF-alpha)-stimulated ICAM-1 expression. Among those flavonoids tested, kaempferol, chrysin, apigenin, and luteolin are active inhibitors of ICAM-1 expression. Additional experiments suggested that apigenin and luteolin were actively inhibiting the IkappaB kinase (IKK) activity, the IkappaBalpha degradation, the nuclear factor-kappaB (NF-kappaB) DNA-protein binding, and the NF-kappaB luciferase activity. TNF-alpha-induced ICAM-1 promoter activity was attenuated using an activator protein-1 (AP-1) site deletion mutant, indicating the involvement of AP-1 in ICAM-1 expression. AP-1-specific DNA-protein binding activity was increased by TNF-alpha, and the supershift assay identified the components of c-fos and c-jun. Extracellular signal-regulated kinase (ERK) and p38 were involved in the c-fos mRNA expression, and c-Jun NH(2)-terminal kinase (JNK) was involved in the c-jun mRNA expression. All three mitogen-activated protein kinase (MAPK) activities were inhibited by apigenin and luteolin. In comparison, kaempferol and chrysin only inhibited the JNK activity. The inhibitory effects of apigenin and luteolin on ICAM-1 expression are mediated by the sequential attenuation of the three MAPKs activities, the c-fos and c-jun mRNA expressions, and the AP-1 transcriptional activity. IKK/NF-kappaB pathway is also involved; however, kaempferol- and chrysin-mediated inhibitions are primarily executed through the attenuation of JNK activity, c-jun mRNA expression, and AP-1 activity. The structure-activity relationships are also explored, and the important role of -OH group at positions 5 and 7 of A ring and at position 4 of B ring is noted. Finally, our results suggested that AP-1 seems to play a more significant role than NF-kappaB in the flavonoid-induced ICAM-1 inhibition.
Mol Pharmacol 2004 Sep
PMID:Flavonoids inhibit tumor necrosis factor-alpha-induced up-regulation of intercellular adhesion molecule-1 (ICAM-1) in respiratory epithelial cells through activator protein-1 and nuclear factor-kappaB: structure-activity relationships. 1532 61

The activation of NF-kappaB and IKK requires an upstream kinase complex consisting of TAK1 and adaptor proteins such as TAB1, TAB2, or TAB3. TAK1 is in turn activated by TRAF6, a RING domain ubiquitin ligase that facilitates the synthesis of lysine 63-linked polyubiquitin chains. Here we present evidence that TAB2 and TAB3 are receptors that bind preferentially to lysine 63-linked polyubiquitin chains through a highly conserved zinc finger (ZnF) domain. Mutations of the ZnF domain abolish the ability of TAB2 and TAB3 to bind polyubiquitin chains, as well as their ability to activate TAK1 and IKK. Significantly, replacement of the ZnF domain with a heterologous ubiquitin binding domain restored the ability of TAB2 and TAB3 to activate TAK1 and IKK. We also show that TAB2 binds to polyubiquitinated RIP following TNFalpha stimulation. These results indicate that polyubiquitin binding domains represent a new class of signaling domains that regulate protein kinase activity through a nonproteolytic mechanism.
Mol Cell 2004 Aug 27
PMID:TAB2 and TAB3 activate the NF-kappaB pathway through binding to polyubiquitin chains. 1532 70


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