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)

The receptor activator of NF-kappaB (RANK) and its ligand RANKL are key molecules for differentiation and activation of osteoclasts. RANKL stimulates transcription factors AP-1 through mitogen-activated protein kinase (MAPK) activation, and NF-kappaB through IkappaB kinase (IKK) activation. Tumor necrosis factor receptor-associated factor 6 (TRAF6) is essential for activation of these kinases. In the interleukin-1 signaling pathway, TAK1 MAPK kinase kinase (MAPKKK) mediates MAPK and IKK activation via interaction with TRAF6, and TAB2 acts as an adapter linking TAK1 and TRAF6. Here, we demonstrate that TAK1 and TAB2 participate in the RANK signaling pathway. Dominant negative forms of TAK1 and TAB2 inhibit NF-kappaB activation induced by overexpression of RANK. In 293 cells stably transfected with full-length RANK, RANKL stimulation facilitates the formation of a complex containing RANK, TRAF6, TAB2, and TAK1, leading to the activation of TAK1. Furthermore, in murine monocyte RAW 264.7 cells, dominant negative forms of TAK1 and TAB2 inhibit NF-kappaB activation induced by RANKL and endogenous TAK1 is activated in response to RANKL stimulation. These results suggest that the formation of the TRAF6-TAB2-TAK1 complex is involved in the RANK signaling pathway and may regulate the development and function of osteoclasts.
Mol Cell Biol 2002 Feb
PMID:Receptor activator of NF-kappaB ligand (RANKL) activates TAK1 mitogen-activated protein kinase kinase kinase through a signaling complex containing RANK, TAB2, and TRAF6. 1180 92

The IKK complex, containing two catalytic subunits IKKalpha and IKKbeta and a regulatory subunit NEMO, plays central roles in signal-dependent activation of NF-kappaB. We identify Cdc37 and Hsp90 as two additional components of the IKK complex. IKKalpha/IKKbeta/NEMO and Cdc37/Hsp90 form an approximately 900 kDa heterocomplex, which is assembled via direct interactions of Cdc37 with Hsp90 and with the kinase domain of IKKalpha/IKKbeta. Geldanamycin (GA), an antitumor agent that disrupts the formation of this heterocomplex, prevents TNF-induced activation of IKK and NF-kappaB. GA treatment reduces the size of the IKK complex and abolishes TNF-dependent recruitment of the IKK complex to TNF receptor 1 (TNF-R1). Therefore, heterocomplex formation with Cdc37/Hsp90 is a prerequisite for TNF-induced activation and trafficking of IKK from the cytoplasm to the membrane.
Mol Cell 2002 Feb
PMID:TNF-induced recruitment and activation of the IKK complex require Cdc37 and Hsp90. 1186 12

Endothelial activation induces expression of pro-inflammatory molecules that are thought to play an important role in atherogenesis through enhanced vascular monocyte recruitment. Many pro-inflammatory endothelial signals are transcriptionally regulated by members of the NF- kappa B family. The serine-threonine kinase, IKK beta, can mediate NF- kappa B activation although several alternative pathways exist. To test whether IKK beta is necessary for cytokine activation of human vascular endothelium and endothelial recruitment of human monocytes under laminar flow, we constructed a recombinant adenoviral vector carrying a dominant negative mutant of IKK beta (Ad.dnIKK beta) to transduce human umbilical vein endothelial cells (HUVEC) in vitro. We found that dnIKK beta expression effectively blocked NF-kappa B activation as assessed by nuclear translocation of NF-kappa B, I kappa B degradation, and NF-kappa B dependent reporter expression, without affecting activation of the other relevant signaling pathways, SAPK/JNK and p38. Furthermore, overexpression of dnIKK beta in TNF-alpha-stimulated HUVEC blocked induction of the surface adhesion molecules E-selectin, ICAM-1, and VCAM-1. Under simulated physiologic flow conditions, both firm adhesion and rolling of human peripheral monocytes on dnIKK beta-transduced endothelial monolayers were markedly inhibited. We conclude that IKK beta is necessary for the cytokine-induced inflammatory phenotype of human endothelium and endothelial recruitment of human monocytes under flow.
J Mol Cell Cardiol 2002 Mar
PMID:Endothelial IKK beta signaling is required for monocyte adhesion under laminar flow conditions. 1194 26

Listeriolysin O (LLO) is a pore-forming cytolysin secreted by the pathogen Listeria monocytogenes and is required for its intracellular survival. We recently demonstrated that in endothelial cells, LLO activates the NF-kappaB signalling pathway. In this work, we studied the LLO-induced molecular cascade of NF-kappaB activation with a cellular model extensively used to analyse the signalling pathway of NF-kappaB activation, i.e. the human embryonic kidney HEK-293 cell line and its derivatives (transfectants or mutants). When the stably transfected derivative HEK-293 cells expressing IL-1RI were exposed to LLO, a strong NF-kappaB activation was detected, contrasting with other cell lines (HEK-293 wild type, HEK-293.T and COS) expressing a very low level of IL-1RI. Although a delayed kinetics of LLO-dependent NF-kappaB activation suggests an autocrine or paracrine IL-1-dependent pathway, we found that LLO-dependent NF-kappaB activation did not require the IL-1 protein synthesis nor the interaction with the IL-1RI specific receptor. Herein, we demonstrated that LLO-dependent NF-kappaB activation requires the activation of the IkappaB kinase beta (IKKbeta) subunit of IKK complex to phosphorylate and degrade cytoplasmic IkappaBalpha, a natural inhibitor of NF-kappaB. The activation induced by LLO does not require the adapters MyD88 and IL-1R-associated kinase (IRAK). We suggested that LLO induces a distinct signalling pathway from that of IL-1 and its receptor.
Mol Microbiol 2002 Jun
PMID:Listeriolysin O secreted by Listeria monocytogenes induces NF-kappaB signalling by activating the IkappaB kinase complex. 1202 84

Endothelins have been implicated in the regulation of cell proliferation, differentiation, and apoptosis, but the mechanisms of these complex events are not yet fully understood. Although the nuclear factor-kappaB (NF-kappaB) was shown to play a prominent role in the above processes, its participation in endothelin receptor A (ET(A)R) signaling has not been previously demonstrated. This study provides evidence that NF-kappaB is involved in ET(A)R-induced proliferation and inhibition of apoptosis. Endothelin (ET)-1, ET-3, and sarafotoxin b induce cell proliferation and prevent apoptosis induced by serum deprivation in a Chinese hamster lung (CCL39) cell line that stably expresses ET(A)R (CCL39ET(A)). Activation of ET(A)R resulted in enhanced DNA-binding activity of NF-kappaB and degradation of IkappaB-alpha. Expression of the dominant negative form of IkappaB-alpha (IkappaB deltaN) inhibited the proliferative activities mediated by ET(A)R as well as its anti-apoptotic activities. Treatment of the cells with prostaglandin A1, an inhibitor of IkappaB kinase-beta, reduced ET-1-induced proliferation and its anti-apoptotic effect. These findings indicate that the regulation of cell proliferation and apoptosis by ET(A)R is mediated by the ET(A)R-activated NF-kappaB.
Cell Mol Neurobiol 2001 Dec
PMID:Involvement of nuclear factor-kappaB in endothelin-A-receptor-induced proliferation and inhibition of apoptosis. 1204 40

To elucidate the mechanisms involved in cell protection by aurintricarboxylic acid (ATA), an endonuclease inhibitor, high nitric oxide (NO)-induced macrophage apoptosis was studied. In RAW 264.7 macrophages, a high level of NO production accompanied by cell apoptosis was apparent with lipopolysaccharide (LPS) treatment. Direct NO donor sodium nitroprusside (SNP) also dramatically induced cell death, with an EC(50) of 1 mM. Coincubation of ATA (1-500 microM) in LPS-stimulated RAW 264.7 cells resulted in a striking reduction of NO production and cell apoptosis, whereas only a partial cell protection was achieved in response to SNP. This suggests that abrogation of inducible nitric-oxide synthase (iNOS)-dependent NO production might contribute to ATA protection of LPS-treated cells. Immunoblotting and reverse transcription-polymerase chain reaction analysis revealed that ATA down-regulated iNOS protein through transcriptional inhibition of iNOS gene expression but was unrelated to iNOS protein stability. ATA not only inhibited nuclear factor-kappaB (NF-kappaB) activation through impairment of the targeting and degradation of IkappaBs but also reduced LPS-induced activator protein-1 (AP-1) activation. These actions of ATA were not caused by the influence on LPS binding to macrophage membrane. Kinase assays indicated that ATA inhibited IkappaB kinase (IKK), extracellular signal-regulated kinase (ERK), and p38 mitogen-activated protein kinase (MAPK) activity both in vivo and in vitro, suggesting a direct interaction between ATA and these signaling molecules. Taken together, these results provide novel action targets of ATA and indicate that ATA protection of macrophages from LPS-mediated cell death is primarily the result of its inhibition of NO production, which closely relates to the inactivation of NF-kappaB and AP-1 and inhibition of IKK, ERK and p38 MAPK.
Mol Pharmacol 2002 Jul
PMID:Aurintricarboxylic acid protects against cell death caused by lipopolysaccharide in macrophages by decreasing inducible nitric-oxide synthase induction via IkappaB kinase, extracellular signal-regulated kinase, and p38 mitogen-activated protein kinase inhibition. 1206 59

Tumor necrosis factor receptor 1 (TNFR1) can trigger distinct signaling pathways leading to either the activation of NF-kappaB transcription factors or apoptosis. NF-kappaB activation results in the expression of antiapoptotic genes that inhibit the apoptosis pathway that is activated in parallel. However, the molecular mechanism of this inhibition remains poorly characterized. We have isolated a Jurkat T-cell mutant that exhibits enhanced sensitivity to TNF-induced apoptosis as a result of a deficiency in I-kappaB kinase gamma (IKKgamma)/NEMO, an essential component of the IKK complex and NF-kappaB pathway. We show here that the zinc finger protein A20 is an NF-kappaB-inducible gene that can protect the IKKgamma-deficient cells from TNF-induced apoptosis by disrupting the recruitment of the death domain signaling molecules TRADD and RIP to the receptor signaling complex. Our study, together with reports on the role of other antiapoptotic proteins such as c-FLIP and c-IAP, suggests that, in order to ensure an effective shutdown of the apoptotic pathway, TNF induces multiple NF-kappaB-dependent genes that inhibit successive steps in the TNFR1 death signaling pathway.
Mol Cell Biol 2002 Sep
PMID:A20 inhibits tumor necrosis factor (TNF) alpha-induced apoptosis by disrupting recruitment of TRADD and RIP to the TNF receptor 1 complex in Jurkat T cells. 1216 98

IkappaB kinase gamma (IKKgamma) (also known as NEMO, Fip-3, and IKKAP-1) is the essential regulatory component of the IKK complex; it is required for NF-kappaB activation by various stimuli, including tumor necrosis factor alpha (TNF-alpha), interleukin 1 (IL-1), phorbol esters, lipopolysaccharides, and double-stranded RNA. IKKgamma is encoded by an X-linked gene, deficiencies in which may result in two human genetic disorders, incontinentia pigmenti (IP) and hypohidrotic ectodermal dysplasia with severe immunodeficiency. Subsequent to the linkage of IKKgamma deficiency to IP, we biochemically characterized the effects of a mutation occurring in an IP-affected family on IKK activity and NF-kappaB signaling. This particular mutation results in premature termination, such that the variant IKKgamma protein lacks its putative C-terminal Zn finger and, due to decreased mRNA stability, is underexpressed. Correspondingly, IKK and NF-kappaB activation by TNF-alpha and, to a lesser extent, IL-1 are reduced. Mutagenesis of the C-terminal region of IKKgamma was performed in an attempt to define the role of the putative Zn finger and other potential functional motifs in this region. The mutants were expressed in IKKgamma-deficient murine embryonic fibroblasts (MEFs) at levels comparable to those of endogenous IKKgamma in wild-type MEFs and were able to associate with IKKalpha and IKKbeta. Substitution of two leucines within a C-terminal leucine zipper motif markedly reduced IKK activation by TNF-alpha and IL-1. Another point mutation resulting in a cysteine-to-serine substitution within the putative Zn finger motif affected IKK activation by TNF-alpha but not by IL-1. These results may explain why cells that express these or similar mutant alleles are sensitive to TNF-alpha-induced apoptosis despite being able to activate NF-kappaB in response to other stimuli.
Mol Cell Biol 2002 Sep
PMID:The carboxyl-terminal region of IkappaB kinase gamma (IKKgamma) is required for full IKK activation. 1219 55

Ligation of the asialoGM1 Pseudomonas aeruginosa pilin receptor has been demonstrated to induce IL-8 expression in airway epithelial cells via an NF-kappaB-dependent pathway. We examined the signaling pathways required for asialoGM1-mediated NF-kappaB activation in IB3 cells, a human bronchial epithelial cell line derived from a cystic fibrosis (CF) patient, and C-38 cells, the rescued cell line that expresses a functional CF transmembrane regulator. Ligation of the asialoGM1 receptor with specific antibody induced greater IL-8 expression in IB3 cells than C-38 cells, consistent with the greater density of asialoGM1 receptors in CF phenotype cells. AsialoGM1-mediated activation of NF-kappaB, IkappaB kinase (IKK), and ERK was also greater in IB3 cells. With the use of genetic inhibitors, we found that IKK-beta and NF-kappaB-inducing kinase are required for maximal NF-kappaB transactivation and transcription from the IL-8 promoter. Finally, although ERK activation was required for maximal asialoGM1-mediated IL-8 expression, inhibition of ERK signaling had no effect on IKK or NF-kappaB activation, suggesting that ERK regulates IL-8 expression in an NF-kappaB-independent manner.
Am J Physiol Lung Cell Mol Physiol 2003 Feb
PMID:Signaling intermediates required for NF-kappa B activation and IL-8 expression in CF bronchial epithelial cells. 1238 60

The proinflammatory cytokine tumor necrosis factor alpha (TNF-alpha) regulates immune responses, inflammation, and programmed cell death (apoptosis). TNF-alpha exerts its biological activities by activating multiple signaling pathways, including IkappaB kinase (IKK), c-Jun N-terminal protein kinase (JNK), and caspases. IKK activation inhibits apoptosis through the transcription factor NF-kappaB, whose target genes include those that encode inhibitors of both caspases and JNK. Despite activation of the antiapoptotic IKK/NF-kappaB pathway, TNF-alpha is able to induce apoptosis in cells sensitive to it, such as human breast carcinoma MCF-7 and mouse fibroblast LM cells. The molecular mechanism underlying TNF-alpha-induced apoptosis is incompletely understood. Here we report that in TNF-alpha-sensitive cells activation of the IKK/NF-kappaB pathway fails to block TNF-alpha-induced apoptosis, although its inactivation still promotes TNF-alpha-induced apoptosis. Interestingly, TNF-alpha-induced apoptosis is suppressed by inhibition of the JNK pathway but promoted by its activation. Furthermore, activation of JNK by TNF-alpha was transient in TNF-alpha-insensitive cells but prolonged in sensitive cells. Conversion of JNK activation from prolonged to transient suppressed TNF-alpha-induced apoptosis. Thus, absence of NF-kappaB-mediated inhibition of JNK activation contributes to TNF-alpha-induced apoptosis.
Mol Cell Biol 2002 Dec
PMID:The absence of NF-kappaB-mediated inhibition of c-Jun N-terminal kinase activation contributes to tumor necrosis factor alpha-induced apoptosis. 1244 76


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