Publication Date:
2010-06-26
Description:
Tumour-necrosis factor (TNF) receptor-associated factor 2 (TRAF2) is a key component in NF-kappaB signalling triggered by TNF-alpha. Genetic evidence indicates that TRAF2 is necessary for the polyubiquitination of receptor interacting protein 1 (RIP1) that then serves as a platform for recruitment and stimulation of IkappaB kinase, leading to activation of the transcription factor NF-kappaB. Although TRAF2 is a RING domain ubiquitin ligase, direct evidence that TRAF2 catalyses the ubiquitination of RIP1 is lacking. TRAF2 binds to sphingosine kinase 1 (SphK1), one of the isoenzymes that generates the pro-survival lipid mediator sphingosine-1-phosphate (S1P) inside cells. Here we show that SphK1 and the production of S1P is necessary for lysine-63-linked polyubiquitination of RIP1, phosphorylation of IkappaB kinase and IkappaBalpha, and IkappaBalpha degradation, leading to NF-kappaB activation. These responses were mediated by intracellular S1P independently of its cell surface G-protein-coupled receptors. S1P specifically binds to TRAF2 at the amino-terminal RING domain and stimulates its E3 ligase activity. S1P, but not dihydro-S1P, markedly increased recombinant TRAF2-catalysed lysine-63-linked, but not lysine-48-linked, polyubiquitination of RIP1 in vitro in the presence of the ubiquitin conjugating enzymes (E2) UbcH13 or UbcH5a. Our data show that TRAF2 is a novel intracellular target of S1P, and that S1P is the missing cofactor for TRAF2 E3 ubiquitin ligase activity, indicating a new paradigm for the regulation of lysine-63-linked polyubiquitination. These results also highlight the key role of SphK1 and its product S1P in TNF-alpha signalling and the canonical NF-kappaB activation pathway important in inflammatory, antiapoptotic and immune processes.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2946785/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉 〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2946785/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Alvarez, Sergio E -- Harikumar, Kuzhuvelil B -- Hait, Nitai C -- Allegood, Jeremy -- Strub, Graham M -- Kim, Eugene Y -- Maceyka, Michael -- Jiang, Hualiang -- Luo, Cheng -- Kordula, Tomasz -- Milstien, Sheldon -- Spiegel, Sarah -- R01 AI050094/AI/NIAID NIH HHS/ -- R01 AI050094-09/AI/NIAID NIH HHS/ -- R01 CA061774/CA/NCI NIH HHS/ -- R01 CA061774-15/CA/NCI NIH HHS/ -- R01 CA061774-16/CA/NCI NIH HHS/ -- R01AI50094/AI/NIAID NIH HHS/ -- R01CA61774/CA/NCI NIH HHS/ -- R37 GM043880/GM/NIGMS NIH HHS/ -- R37 GM043880-18/GM/NIGMS NIH HHS/ -- R37 GM043880-19/GM/NIGMS NIH HHS/ -- R37 GM043880-20/GM/NIGMS NIH HHS/ -- R37 GM043880-21/GM/NIGMS NIH HHS/ -- R37GM043880/GM/NIGMS NIH HHS/ -- U19 AI077435/AI/NIAID NIH HHS/ -- U19 AI077435-020004/AI/NIAID NIH HHS/ -- U19 AI077435-02S10004/AI/NIAID NIH HHS/ -- U19 AI077435-030004/AI/NIAID NIH HHS/ -- U19AI077435/AI/NIAID NIH HHS/ -- England -- Nature. 2010 Jun 24;465(7301):1084-8. doi: 10.1038/nature09128.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry and Molecular Biology and the Massey Cancer Center, Virginia Commonwealth University School of Medicine, 1101 E. Marshall Street, Richmond, Virginia 23298, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20577214" target="_blank"〉PubMed〈/a〉
Keywords:
Animals
;
Biocatalysis
;
Cell Line
;
Enzyme Activation
;
Humans
;
I-kappa B Kinase/metabolism
;
I-kappa B Proteins/metabolism
;
Lysine/metabolism
;
Lysophospholipids/biosynthesis/chemistry/*metabolism
;
Mice
;
Models, Molecular
;
NF-kappa B/metabolism
;
Phosphorylation
;
Phosphotransferases (Alcohol Group Acceptor)/genetics/metabolism
;
Protein Binding
;
Protein Structure, Tertiary
;
Receptor-Interacting Protein Serine-Threonine Kinases/metabolism
;
Sphingosine/*analogs & derivatives/biosynthesis/chemistry/metabolism
;
Substrate Specificity
;
TNF Receptor-Associated Factor 2/chemistry/*metabolism
;
Tumor Necrosis Factor-alpha/pharmacology
;
Ubiquitin-Conjugating Enzymes/metabolism
;
Ubiquitin-Protein Ligases/*metabolism
;
Ubiquitination/drug effects
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
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