scholarly journals Interleukin-1-receptor-associated kinase 2 (IRAK2)-mediated interleukin-1-dependent nuclear factor κB transactivation in Saos2 cells requires the Akt/protein kinase B kinase

2003 ◽  
Vol 376 (1) ◽  
pp. 303-311 ◽  
Author(s):  
Vittoria CENNI ◽  
Alessandra SIRRI ◽  
Anto De Pol ◽  
Nadir Mario MARALDI ◽  
Sandra MARMIROLI
Keyword(s):  
Protein Kinase ◽  
Interleukin 1 ◽  
Nuclear Factor Κb ◽  
Dominant Negative ◽  
Tumour Necrosis Factor Receptor ◽  
Nuclear Factor ◽  
Transactivation Domain ◽  
Defective Mutant ◽  
Gene Reporter Assay ◽  
Pre Treatment

The post-receptor pathway that leads to nuclear factor κB (NF-κB) activation begins with the assembly of a membrane-proximal complex among the interleukin 1 (IL-1) receptors and the adaptor molecules, myeloid differentiation protein 88 (MyD88), IL-1-receptor-associated kinases (IRAKs) and tumour-necrosis-factor-receptor-associated factor 6. Eventually, phosphorylation of the inhibitor of NF-κB (IκB) by the IκB kinases releases NF-κB, which translocates to the nucleus and modulates gene expression. In this paper, we report that IRAK2 and MyD88, but not IRAK1, interact physically with Akt, as demonstrated by co-immunoprecipitation and pull-down experiments. Interestingly, the association of Akt with recombinant IRAK2 is decreased by stimulation with IL-1, and is favoured by pre-treatment with phosphatase. Likewise, Akt association with IRAK2 is increased considerably by overexpression of PTEN (phosphatase and tensin homologue deleted on chromosome 10), while it is completely abrogated by overexpression of phosphoinositide-dependent protein kinase 1. These data indicate that Akt takes part in the formation of the signalling complex that conveys the signal from the IL-1 receptors to NF-κB, a step that is much more membrane-proximal than was reported previously. We also demonstrate that Akt activity is necessary for IL-1-dependent NF-κB transactivation, since a kinase-defective mutant of Akt impairs IRAK2- and MyD88-dependent, but not IRAK1-dependent, NF-κB activity, as monitored by a gene reporter assay. Accordingly, IRAK2 failed to trigger inducible nitric oxide synthase and IL-1β production in cells expressing dominant-negative Akt. However, NF-κB binding to DNA was not affected by inhibition of Akt, indicating that Akt regulates NF-κB at a level distinct from the dissociation of p65 from IκBα and its translocation to the nucleus, possibly involving phosphorylation of the p65 transactivation domain.

scholarly journals A novel splice variant of mouse interleukin-1-receptor-associated kinase-1 (IRAK-1) activates nuclear factor-kappaB (NF-kappaB) and c-Jun N-terminal kinase (JNK)

2003 ◽  
Vol 370 (1) ◽  
pp. 159-166 ◽  
Author(s):  
Ken YANAGISAWA ◽  
Kenji TAGO ◽  
Morisada HAYAKAWA ◽  
Motomichi OHKI ◽  
Hiroyuki IWAHANA ◽  
...  
Keyword(s):  
Splice Variant ◽  
Interleukin 1 ◽  
Nuclear Factor Κb ◽  
Tumour Necrosis Factor Receptor ◽  
Acceptor Site ◽  
Nuclear Factor ◽  
Death Domain ◽  
Signalling Molecule ◽  
Novel Variant ◽  
Nf Kappab

Interleukin-1 (IL-1)-receptor-associated kinase (IRAK) is an indispensable signalling molecule for host-defence responses initiated by a variety of ligands that bind to members of the Toll/IL-1 receptor family. Here we report a novel splice variant of mouse IRAK-1, IRAK-1-S, which is generated by utilizing a new splicing acceptor site within exon 12. IRAK-1-S cDNA is shorter than the originally reported IRAK-1 (IRAK-1-W) cDNA by 271 nucleotides, and the subsequent frameshift causes a premature termination of translation after 23 amino acids, which are unique to the IRAK-1-S protein. To elucidate the physiological function of IRAK-1-S, we overexpressed it in 293T cells and studied the effects on the IL-1 signalling cascade. As it lacks the C-terminal region of IRAK-1-W that has been reported to contain the TRAF6 (tumour necrosis factor receptor-associated factor 6) binding domain, IRAK-1-S was unable to bind TRAF6 protein, which is a proposed downstream signalling molecule. However, IRAK-1-S overexpressed in 293T cells induced constitutive activation of nuclear factor-κB (NF-κB) and c-Jun N-terminal kinase (JNK) independent of stimulation by IL-1, as did IRAK-1-W. To clarify the mechanism of NF-κB activation by IRAK-1-S in the absence of binding to TRAF6, we demonstrated that IRAK-1-S binds to IRAK-1-W through its death domain; the findings suggested that overexpressed IRAK-1-S may bind endogenous IRAK-1-W and activate TRAF6 through IRAK-1-W. These results also indicate that this novel variant may play roles in the activation of NF-κB and JNK by IL-1 and other ligands whose signal transduction is dependent on IRAK-1 under physiological conditions.

scholarly journals Overexpression of an enzymically inactive interleukin-1-receptor-associated kinase activates nuclear factor-κB

1999 ◽  
Vol 339 (2) ◽  
pp. 227-231 ◽  
Author(s):  
Barbara MASCHERA ◽  
Keith RAY ◽  
Kimberly BURNS ◽  
Filippo VOLPE
Keyword(s):  
Kinase Activity ◽  
Interleukin 1 ◽  
Nuclear Factor Κb ◽  
Nuclear Factor ◽  
Wild Type ◽  
Defective Mutant ◽  
Asparagine Residue

Upon interleukin 1 (IL-1) stimulation, the IL-1-receptor (IL-1R)-associated kinase (IRAK) is rapidly recruited to the IL-1R complex and undergoes phosphorylation. Here we demonstrate that recombinant wild-type IRAK (IRAK-WT), but not a kinase-defective mutant with Asp340 replaced by an asparagine residue (IRAK-Asp340Asn), is highly phosphorylated and is capable of auto-phosphorylation in vitro. Overexpression of both IRAK-WT and IRAK-Asp340Asn caused activation of nuclear factor κB, suggesting that the kinase activity of IRAK is not required outside of the IL-1R complex.

scholarly journals Bioflavonoid Quercetin Inhibits Interleukin-1-Induced Transcriptional Expression of Monocyte Chemoattractant Protein-1 in Glomerular Cells via Suppression of Nuclear Factor-κB

1999 ◽  
Vol 10 (11) ◽  
pp. 2290-2296
Author(s):  
YOSHIHISA ISHIKAWA ◽  
HITOSHI SUGIYAMA ◽  
ELENI STYLIANOU ◽  
MASANORI KITAMURA
Keyword(s):  
Mesangial Cells ◽  
Interleukin 1 ◽  
Nuclear Factor Κb ◽  
Dominant Negative ◽  
Dominant Negative Mutant ◽  
Nuclear Factor ◽  
Monocyte Chemoattractant Protein 1 ◽  
Isolated Glomeruli ◽  
Monocyte Chemoattractant ◽  
Monocyte Chemoattractant Protein

Abstract. Flavonoids are semiessential food components that possess anti-inflammatory properties. This report describes a novel potential of bioflavonoid quercetin as an inhibitor of monocyte chemoattractant protein-1 (MCP-1) in glomerular cells. Cultured mesangial cells as well as isolated glomeruli expressed MCP-1 mRNA in response to interleukin-1β (IL-1β). Quercetin dramatically inhibited the cytokine-triggered MCP-1 expression. To explore the mechanisms involved, effects of quercetin on the putative transcriptional activators of MCP-1, nuclear factor-κB (NF-κB) and activator protein-1 (AP-1), were examined. Exposure of the cells to IL-1β caused activation of NF-κB without significant upregulation of AP-1 activity. NF-κB inhibitor MG132 diminished the IL-1-induced expression of MCP-1 in mesangial cells and isolated glomeruli, whereas c-Jun/Ap-1 inhibitor curcumin did not affect this process. Consistently, NF-κB-inactive mesangial cells expressing a super-repressor mutant of IκBα showed blunted expression of MCP-1 by IL-1β. In contrast, AP-1-inactive mesangial cells expressing a dominant-negative mutant of c-Jun exhibited the same level of MCP-1 mRNA as that in control cells. These results suggest that: (1) quercetin has the ability to attenuate activation of NF-κB; and (2) it inhibits IL-1-triggered MCP-1 expression via suppression of NF-κB, but not AP-1, in glomerular cells.

scholarly journals The Human Toll Signaling Pathway: Divergence of Nuclear Factor κB and JNK/SAPK Activation Upstream of Tumor Necrosis Factor Receptor–associated Factor 6 (TRAF6)

1998 ◽  
Vol 187 (12) ◽  
pp. 2097-2101 ◽  
Author(s):  
Marta Muzio ◽  
Gioacchino Natoli ◽  
Simona Saccani ◽  
Massimo Levrero ◽  
Alberto Mantovani
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Interleukin 1 ◽  
Tumor Necrosis Factor Receptor ◽  
Nuclear Factor Κb ◽  
Dominant Negative ◽  
Nuclear Factor ◽  
Kinase C ◽  
Toll Signaling ◽  
Necrosis Factor

The human homologue of Drosophila Toll (hToll) is a recently cloned receptor of the interleukin 1 receptor (IL-1R) superfamily, and has been implicated in the activation of adaptive immunity. Signaling by hToll is shown to occur through sequential recruitment of the adapter molecule MyD88 and the IL-1R–associated kinase. Tumor necrosis factor receptor–activated factor 6 (TRAF6) and the nuclear factor κB (NF-κB)–inducing kinase (NIK) are both involved in subsequent steps of NF-κB activation. Conversely, a dominant negative version of TRAF6 failed to block hToll-induced activation of stress-activated protein kinase/c-Jun NH2-terminal kinases, thus suggesting an early divergence of the two pathways.

scholarly journals The role of TBK1 and IKKϵ in the expression and activation of Pellino 1

2011 ◽  
Vol 434 (3) ◽  
pp. 537-548 ◽  
Author(s):  
Hilary Smith ◽  
Xin-Yu Liu ◽  
Liang Dai ◽  
Eddy T. H. Goh ◽  
Aye-Thu Chan ◽  
...  
Keyword(s):  
Protein Expression ◽  
Interleukin 1 ◽  
E3 Ligase ◽  
Nuclear Factor Κb ◽  
Poly I:C ◽  
Tumour Necrosis Factor Receptor ◽  
Nuclear Factor ◽  
Gene Encoding ◽  
Gene And Protein Expression

Mammalian Pellino isoforms are phosphorylated by IRAK (interleukin receptor associated kinase) 1/IRAK4 in vitro, converting them into active E3 ubiquitin ligases. In the present paper we report a striking enhancement in both transcription of the gene encoding Pellino 1 and Pellino 1 protein expression when murine BMDMs (bone-marrow-derived macrophages) are stimulated with LPS (lipopolysaccharide) or poly(I:C). This induction occurs via a TRIF [TIR (Toll/interleukin-1 receptor)-domain-containing adaptor-inducing interferon-β]-dependent IRAK-independent pathway and is prevented by inhibition of the IKK [IκB (inhibitor of nuclear factor κB) kinase]-related protein kinases, TBK1 {TANK [TRAF (tumour-necrosis-factor-receptor-associated factor)-associated nuclear factor κB activator]-binding kinase 1} and IKKϵ. Pellino 1 is not induced in IRF3 (interferon regulatory factor 3)−/− BMDMs, and its induction is only reduced slightly in type 1 interferon receptor−/− BMDMs, identifying Pellino 1 as a new IRF3-dependent gene. We also identify Pellino 1 in a two-hybrid screen using IKKϵ as bait, and show that IKKϵ/TBK1 activate Pellino 1 in vitro by phosphorylating Ser76, Thr288 and Ser293. Moreover, we show that the E3 ligase activity of endogenous Pellino 1 is activated in LPS- or poly(I:C)-stimulated macrophages. This occurs more rapidly than the increase in Pellino 1 mRNA and protein expression, is prevented by the inhibition of IKKϵ/TBK1 and is reversed by phosphatase treatment. Thus IKKϵ/TBK1 mediate the activation of Pellino 1's E3 ligase activity, as well as inducing the transcription of its gene and protein expression in response to TLR3 and TLR4 agonists.

scholarly journals Activation of Nuclear Factor κB (NF-κB) in Prostate Cancer Is Mediated by Protein Kinase C ϵ (PKCϵ)

2012 ◽  
Vol 287 (44) ◽  
pp. 37570-37582 ◽  
Author(s):  
Rachana Garg ◽  
Jorge Blando ◽  
Carlos J. Perez ◽  
HongBin Wang ◽  
Fernando J. Benavides ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Nuclear Factor Κb ◽  
Nuclear Factor ◽  
Kinase C
Sign in / Sign up

Export Citation Format

Share Document