Effects of the NIK aly mutation on NF-kappaB activation by the Epstein-Barr virus latent infection membrane protein, lymphotoxin beta receptor, and CD40.
Homozygosity for the aly point mutation in NF-kappaB-inducing kinase (NIK) results in alymphoplasia in mice, a phenotype similar to that of homozygosity for deletion of the lymphotoxin beta receptor (LTbetaR). We now find that NF-kappaB activation by Epstein-Barr virus latent membrane protein 1 (LMP1) or by an LMP1 transmembrane domain chimera with the LTbetaR signaling domain in human embryonic kidney 293 cells is selectively inhibited by a wild type dominant negative NIK comprised of amino acids 624-947 (DN-NIK) and not by aly DN-NIK. In contrast, LMP1/CD40 is inhibited by both wild type (wt) and aly DN-NIK. LMP1, an LMP1 transmembrane domain chimera with the LTbetaR signaling domain, and LMP1/CD40 activate NF-kappaB in wt or aly murine embryo fibroblasts. Although wt and aly NIK do not differ in their in vitro binding to tumor necrosis factor receptor-associated factor 1, 2, 3, or 6 or in their in vivo association with tumor necrosis factor receptor-associated factor 2 and differ marginally in their very poor binding to IkappaB kinase beta (IKKbeta), only wt NIK is able to bind to IKKalpha. These data are compatible with a model in which activation of NF-kappaB by LMP1 and LTbetaR is mediated by an interaction of NIK or a NIK-like kinase with IKKalpha that is abrogated by the aly mutation. On the other hand, CD40 mediates NF-kappaB activation through a kinase that interacts with a different component of the IKK complex.
Departments of Microbiology and Molecular Genetics and Medicine, Program in Virology, Harvard Medical School, Boston, Massachusetts 02115, USA.
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Luftig
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Cahir-McFarland
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Mosialos
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Kieff
D001483:Base Sequence; D019013:CD40 Antigens / Q000378:metabolism; D002460:Cell Line; D017931:DNA Primers; D006801:Humans; D051550:I-kappa B Kinase; D053259:Lymphotoxin beta Receptor; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D016328:NF-kappa B / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics* / Q000378:metabolism; D018124:Receptors, Tumor Necrosis Factor / Q000378:metabolism*; D014763:Viral Matrix Proteins / Q000378:metabolism*; D000097782:NF-kappaB-Inducing Kinase
D019013:CD40 Antigens; D017931:DNA Primers; D051550:I-kappa B Kinase; D053259:Lymphotoxin beta Receptor; D016328:NF-kappa B; D017346:Protein Serine-Threonine Kinases; D018124:Receptors, Tumor Necrosis Factor; D014763:Viral Matrix Proteins; D000097782:NF-kappaB-Inducing Kinase; C037662:EBV-associated membrane antigen, Epstein-Barr virus; C505697:LTBR protein, human; C496559:CHUK protein, human; C496560:IKBKB protein, human; C496565:IKBKE protein, human