title: Interleukin-1 receptor-associated kinase-2 genetic variant rs708035 increases NF-κB activity through promoting TRAF6 ubiquitination.
abstract: The IL-1 receptor-associated kinases (IRAKs) are key regulators of Toll-like receptor (TLR)/IL-1 signaling, which are critical regulators of mammalian inflammation and innate immune response. Single nucleotide polymorphisms (SNPs) within the IRAK genes have been discovered recently. However, the functions of these IRAK SNPs remain largely unknown. Here, we found that the non-synonymous IRAK2 variant rs708035 (coding D431E) increases NF-κB activity and leads to more expression of NF-κB-dependent proinflammatory cytokines compared with IRAK2 wild type. Moreover, when IRAK2 knockdown cells reconstituted with siRNA-resistant WT-IRAK2 or D431E-IRAK2 were infected with influenza virus, a more obvious induction of IL-6 and a stronger anti-apoptosis effect were observed in D431E-IRAK2 expressing cells. Notably, we also found that the levels of proinflammatory cytokine-IL-6 were indeed higher in people carrying D431E-IRAK2 than those carrying WT-IRAK2. Further study demonstrated that elevated NF-κB activation mediated by the IRAK2 variant was due to increased TRAF6 ubiquitination and faster IκBα degradation. Our study provides important insight of IRAK2 SNP in the regulation of NF-κB activation and indicates that IRAK2 rs708035 might be associated with human diseases caused by hyper-activation of NF-κB.
authors.affiliation: From the Beijing Institute of Biotechnology, Beijing 100071.
authors.forename: Weina
authors.initials: W
authors.lastname: Zhang
authors.forename: Tao
authors.initials: T
authors.lastname: He
authors.forename: Qiong
authors.initials: Q
authors.lastname: Wang
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.forename: Jianming
authors.initials: J
authors.lastname: Wei
authors.forename: Xiaoqiang
authors.initials: X
authors.lastname: Hou
authors.forename: Bin
authors.initials: B
authors.lastname: Zhang
authors.forename: Lei
authors.initials: L
authors.lastname: Huang
authors.forename: Li
authors.initials: L
authors.lastname: Wang
mesh_terms: D019943:Amino Acid Substitution; D017209:Apoptosis / Q000235:genetics; D002460:Cell Line; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D015870:Gene Expression; D045325:HCT116 Cells; D057809:HEK293 Cells; D006367:HeLa Cells; D054884:Host-Pathogen Interactions; D006801:Humans; D015151:Immunoblotting; D053118:Influenza A Virus, H1N1 Subtype / Q000502:physiology; D053592:Interleukin-1 Receptor-Associated Kinases / Q000235:genetics*; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism; D016209:Interleukin-8 / Q000235:genetics / Q000378:metabolism; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism*; D020641:Polymorphism, Single Nucleotide; D011485:Protein Binding; D034622:RNA Interference; D020133:Reverse Transcriptase Polymerase Chain Reaction; D048029:TNF Receptor-Associated Factor 6 / Q000378:metabolism*; D051196:Toll-Like Receptor 3 / Q000235:genetics / Q000378:metabolism; D054875:Ubiquitination
chemical_list: D015850:Interleukin-6; D016209:Interleukin-8; D016328:NF-kappa B; D048029:TNF Receptor-Associated Factor 6; D051196:Toll-Like Receptor 3; D008156:Luciferases; D053592:Interleukin-1 Receptor-Associated Kinases
keywords: Cell Biology; Gene Regulation; Inflammation; Signal Transduction; Toll-like Receptors (TLR)