Dataset Information

Tyrosine phosphorylation allows integration of multiple signaling inputs by IKK?.

ABSTRACT: Signaling regulated by NF?B and related transcription factors is centrally important to many inflammatory and autoimmune diseases, cancer, and stress responses. The kinase that directly regulates the canonical NF?B transcriptional pathway, Inhibitor of ?B kinase ? (IKK?), undergoes activation by Ser phosphorylation mediated by NIK or TAK1 in response to inflammatory signals. Using titanium dioxide-based phosphopeptide enrichment (TiO2)-liquid chromatography (LC)-high mass accuracy tandem mass spectrometry (MS/MS), we analyzed IKK? phosphorylation in human HEK293 cells expressing IKK? and FGFR2, a Receptor tyrosine kinase (RTK) essential for embryonic differentiation and dysregulated in several cancers. We attained unusually high coverage of IKK?, identifying an abundant site of Tyr phosphorylation at Tyr169 within the Activation Loop. The phosphomimic at this site confers a level of kinase activation and NF?B nuclear localization exceeding the iconic mutant S177E/S181E, demonstrating that RTK-mediated Tyr phosphorylation of IKK? has the potential to directly regulate NF?B transcriptional activation.

SUBMITTER: Meyer AN

PROVIDER: S-EPMC3873999 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Tyrosine phosphorylation allows integration of multiple signaling inputs by IKKβ.

Meyer April N AN Drafahl Kristine A KA McAndrew Christopher W CW Gilda Jennifer E JE Gallo Leandro H LH Haas Martin M Brill Laurence M LM Donoghue Daniel J DJ

PloS one 20131227 12

Signaling regulated by NFκB and related transcription factors is centrally important to many inflammatory and autoimmune diseases, cancer, and stress responses. The kinase that directly regulates the canonical NFκB transcriptional pathway, Inhibitor of κB kinase β (IKKβ), undergoes activation by Ser phosphorylation mediated by NIK or TAK1 in response to inflammatory signals. Using titanium dioxide-based phosphopeptide enrichment (TiO2)-liquid chromatography (LC)-high mass accuracy tandem mass sp ...[more]

PMID: 24386391

Similar Datasets

Project description:UnlabelledThe NF-κB signaling network, which is an ancient signaling pathway, plays a pivotal role in innate immunity and constitutes a first line of defense against invading pathogens, including viruses. However, numerous viruses possess evolved strategies to antagonize the activation of the NF-κB signaling pathway. Our previous study demonstrated that the nonstructural protein 2C of enterovirus 71 (EV71), which is the major pathogen of hand, foot, and mouth disease, inhibits tumor necrosis factor alpha (TNF-α)-mediated activation of NF-κB by suppressing IκB kinase β (IKKβ) phosphorylation. Nevertheless, the mechanism underlying the inhibition of IKKβ phosphorylation by EV71 2C remains largely elusive. We demonstrate that EV71 2C interacts with all isoforms of the protein phosphatase 1 (PP1) catalytic subunit (the PP1α, PP1β, and PP1γ isoforms) through PP1-docking motifs. EV71 2C has no influence on the subcellular localization of PP1. In addition, the PP1-binding-deficient EV71 2C mutant 3E3L nearly completely lost the ability to suppress IKKβ phosphorylation and NF-κB activation was markedly restored in the mutant, thereby indicating that PP1 binding is efficient for EV71 2C-mediated inhibition of IKKβ phosphorylation and NF-κB activation. We further demonstrate that 2C forms a complex with PP1 and IKKβ to dephosphorylate IKKβ. Notably, we reveal that other human enteroviruses, including poliovirus (PV), coxsackie A virus 16 (CVA16), and coxsackie B virus 3 (CVB3), use 2C proteins to recruit PP1, leading to the inhibition of IKKβ phosphorylation. Our findings indicate that enteroviruses exploit a novel mechanism to inhibit IKKβ phosphorylation by recruiting PP1 and IKKβ to form a complex through 2C proteins, which ultimately results in the inhibition of the NF-κB signaling pathway.ImportanceThe innate antiviral immunity system performs an essential function in recognizing and eliminating invading viruses. Enteroviruses include a number of important human pathogens, including poliovirus (PV), EV71, and coxsackieviruses (CVs). As 2C is the most conserved and complex nonstructural protein of enteroviruses, its biological function is largely unclear, whereas the 2A and 3C proteinases of enteroviruses are well characterized. We reveal that EV71 2C forms a complex with PP1 and IKKβ to maintain IKKβ in an unphosphorylated and inactive state, resulting in the inactivation of the TNF-α-mediated NF-κB signaling pathway. We provide evidence that the 2C proteins of the enteroviruses PV, CVA16, and CVB3 suppress IKKβ phosphorylation through the same mechanism involving PP1. We demonstrate that enteroviruses exploit a novel mechanism involving PP1 to regulate innate antiviral immunity, and our findings may be particularly important for understanding the pathogenicity of enteroviruses.

Dataset Information

Tyrosine phosphorylation allows integration of multiple signaling inputs by IKK?.

Publications

Tyrosine phosphorylation allows integration of multiple signaling inputs by IKKβ.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets