Notch1 augments NF-kappaB activity by facilitating its nuclear retention

EMBO J. 2006 Jan 11;25(1):129-38. doi: 10.1038/sj.emboj.7600902. Epub 2005 Dec 1.


Notch1 specifically upregulates expression of the cytokine interferon-gamma in peripheral T cells through activation of NF-kappaB. However, how Notch mediates NF-kappaB activation remains unclear. Here, we examined the temporal relationship between Notch signaling and NF-kappaB induction during T-cell activation. NF-kappaB activation occurs within minutes of T-cell receptor (TCR) engagement and this activation is sustained for at least 48 h following TCR signaling. We used gamma-secretase inhibitor (GSI) to prevent the cleavage and subsequent activation of Notch family members. We demonstrate that GSI blocked the later, sustained NF-kappaB activation, but did not affect the initial activation of NF-kappaB. Using biochemical approaches, as well as confocal microscopy, we show that the intracellular domain of Notch1 (N1IC) directly interacts with NF-kappaB and competes with IkappaBalpha, leading to retention of NF-kappaB in the nucleus. Additionally, we show that N1IC can directly regulate IFN-gamma expression through complexes formed on the IFN-gamma promoter. Taken together, these data suggest that there are two 'waves' of NF-kappaB activation: an initial, Notch-independent phase, and a later, sustained activation of NF-kappaB, which is Notch dependent.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Antibodies / pharmacology
  • CD28 Antigens / immunology
  • CD3 Complex / immunology
  • Cell Nucleus / chemistry
  • Cell Nucleus / metabolism*
  • Cytosol / chemistry
  • Cytosol / metabolism
  • Gene Expression Regulation*
  • I-kappa B Proteins / metabolism*
  • Interferon-gamma / genetics*
  • Lymphocyte Activation
  • Mice
  • Mice, Inbred C57BL
  • NF-KappaB Inhibitor alpha
  • NF-kappa B / analysis
  • NF-kappa B / metabolism*
  • NF-kappa B p50 Subunit / genetics
  • Promoter Regions, Genetic
  • Proto-Oncogene Proteins c-rel / genetics
  • Receptor, Notch1 / metabolism*
  • Signal Transduction
  • Spleen / cytology
  • Spleen / drug effects
  • Spleen / immunology
  • T-Lymphocytes / immunology


  • Antibodies
  • CD28 Antigens
  • CD3 Complex
  • Cd3e protein, mouse
  • I-kappa B Proteins
  • NF-kappa B
  • NF-kappa B p50 Subunit
  • Nfkbia protein, mouse
  • Notch1 protein, mouse
  • Proto-Oncogene Proteins c-rel
  • Receptor, Notch1
  • NF-KappaB Inhibitor alpha
  • Interferon-gamma