Epstein-Barr virus latent membrane protein 1 activation of NF-kappaB through IRAK1 and TRAF6.
Epstein-Barr virus latent membrane protein 1 (LMP1) activation of NF-kappaB is critical for Epstein-Barr virus-infected B lymphocyte survival. LMP1 activates the IkappaB kinase complex and NF-kappaB through two cytoplasmic signaling domains that engage tumor necrosis factor receptor-associated factor (TRAF)1/2/3/5 or TRADD and RIP. We now use cells lacking expression of TRAF2, TRAF5, TRAF6, IKKalpha, IKKbeta, IKKgamma, TAB2, IL-1 receptor-associated kinase (IRAK)1, or IRAK4 to assess their roles in LMP1-mediated NF-kappaB activation. LMP1-induced RelA nuclear translocation was similar in IKKalpha knockout (KO) and WT murine embryo fibroblasts (MEFs) but substantially deficient in IKKbeta KO MEFs. NF-kappaB-dependent promoter responses were also substantially deficient in IKKbeta KO MEFs but were hyperactive in IKKalpha KO MEFs. More surprisingly, NF-kappaB responses were near normal in TRAF2 and TRAF5 double-KO MEFs, IKKgamma KO MEFs, TAB2 KO MEFs, and IRAK4 KO MEFs but were highly deficient in TRAF6 KO MEFs and IRAK1 KO HEK293 cells. Consistent with the importance of TRAF6, LMP1-induced NF-kappaB activation in HEK293 cells was inhibited by expression of dominant-negative TAB2 and Ubc13 alleles. These data extend a role for IKKalpha in IKKbeta regulation, identify an unusual IKKbeta-dependent and IKKgamma-independent NF-kappaB activation, and indicate that IRAK1 and TRAF6 are essential for LMP1-induced NF-kappaB activation.
Luftig
Micah
M
Program in Virology, Department of Microbiology and Molecular Genetics, Harvard Medical School, Channing Laboratory/Brigham and Women's Hospital, 181 Longwood Avenue, Boston, MA 02115.
Prinarakis
Efthimios
E
Yasui
Teruhito
T
Tsichritzis
Theodore
T
Cahir-McFarland
Ellen
E
Inoue
Jun-Ichiro
J
Nakano
Hiroyasu
H
Mak
Tak Wah
TW
Yeh
Wen-Chen
WC
Li
Xiaoxia
X
Akira
Shizuo
S
Suzuki
Nobutaka
N
Suzuki
Shinobu
S
Mosialos
George
G
Kieff
Elliott
E
D001402:B-Lymphocytes / Q000502:physiology* / Q000821:virology; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D017930:Genes, Reporter; D004854:Herpesvirus 4, Human / Q000502:physiology; D006801:Humans; D053592:Interleukin-1 Receptor-Associated Kinases; D008156:Luciferases / Q000235:genetics; D016328:NF-kappa B / Q000378:metabolism*; D011494:Protein Kinases / Q000378:metabolism*; D021381:Protein Transport; D011506:Proteins / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015398:Signal Transduction; D048029:TNF Receptor-Associated Factor 6; D014162:Transfection; D014763:Viral Matrix Proteins / Q000378:metabolism*
C037662:EBV-associated membrane antigen, Epstein-Barr virus; D016328:NF-kappa B; D011506:Proteins; D011993:Recombinant Fusion Proteins; D048029:TNF Receptor-Associated Factor 6; D014763:Viral Matrix Proteins; D008156:Luciferases; D011494:Protein Kinases; C507768:IRAK1 protein, human; C507773:IRAK4 protein, human; D053592:Interleukin-1 Receptor-Associated Kinases