Negative regulation of NF-kappaB action by Set9-mediated lysine methylation of the RelA subunit.
Proper regulation of NF-kappaB activity is critical to maintain and balance the inflammatory response. Inactivation of the NF-kappaB complex relies in part on the proteasome-mediated degradation of promoter-bound NF-kappaB, but the detailed molecular mechanism initiating this process remains elusive. Here, we show that the methylation of the RelA subunit of NF-kappaB has an important function in this process. Lysine methyltransferase Set9 physically associates with RelA in vitro and in vivo in response to TNF-alpha stimulation. Mutational and mass spectrometric analyses reveal that RelA is monomethylated by Set9 at lysine residues 314 and 315 in vitro and in vivo. Methylation of RelA inhibits NF-kappaB action by inducing the proteasome-mediated degradation of promoter-associated RelA. Depletion of Set9 by siRNA or mutation of the RelA methylation sites prolongs DNA binding of NF-kappaB and enhances TNF-alpha-induced expression of NF-kappaB target genes. Together, these findings unveil a novel mechanism by which methylation of RelA dictates the turnover of NF-kappaB and controls the NF-kappaB-mediated inflammatory response.
Yang
Xiao-Dong
XD
Department of Biochemistry, College of Medicine, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
Huang
Bo
B
Li
Mingxi
M
Lamb
Acacia
A
Kelleher
Neil L
NL
Chen
Lin-Feng
LF
D000595:Amino Acid Sequence; D000076983:Histone Methyltransferases; D011495:Histone-Lysine N-Methyltransferase; D006801:Humans; D008239:Lysine / Q000378:metabolism*; D008745:Methylation; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011496:Protein Methyltransferases / Q000235:genetics / Q000378:metabolism*; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D051996:Transcription Factor RelA / Q000235:genetics / Q000378:metabolism*; D015533:Transcriptional Activation; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D016328:NF-kappa B; D021122:Protein Subunits; D011993:Recombinant Fusion Proteins; D051996:Transcription Factor RelA; D014409:Tumor Necrosis Factor-alpha; D000076983:Histone Methyltransferases; D011496:Protein Methyltransferases; D011495:Histone-Lysine N-Methyltransferase; C540312:SETD7 protein, human; D008239:Lysine