PMCCPMCCPMCC

Search tips
Search criteria 

Advanced

 
Logo of jexpmedHomeThe Rockefeller University PressEditorsContactInstructions for AuthorsThis issue
 
J Exp Med. 1996 May 1; 183(5): 2025–2032.
PMCID: PMC2192574

T cell leukemia-associated human Notch/translocation-associated Notch homologue has I kappa B-like activity and physically interacts with nuclear factor-kappa B proteins in T cells

Abstract

Translocation-associated Notch homologue (TAN-1), a gene originally cloned from the translocation breakpoint of a human T cell leukemia carrying a 9:7(q34.3) translocation, encodes a protein belonging to the Notch/Lin-12/Glp-1 receptor family. These receptors mediate the specification of numerous cell fates during development in invertebrates and vertebrates. The intracellular portion of Notch/TAN-1 contains six ankyrin repeats that are similar to those found in cytoplasmic I kappa B proteins. I kappa B proteins are specific inhibitors of nuclear factor (NF)-kappa B/Rel transcription factors. Here we show that TAN-1 has functional properties of an I kappa B-like regulator with specificity for the NF-kappa B p50 subunit. A recombinant polypeptide corresponding to the cytoplasmic portion of TAN- 1 (TAN-1C) specifically inhibited the DNA binding of p50-containing NF- kappa B complexes. When overexpressed in an appropriate cell line, TAN- 1C prevented kappa B-dependent transactivation in transient reporter gene assays in a fashion similar to the structurally related protein, Bcl-3. TAN-1C could activate kappa B-dependent gene expression by attenuating the inhibitory effect of an excess of p50 homodimers. Immunoprecipitation experiments showed that the TAN-1 from a T cell line is associated with NF-kappa B containing p50 and p65 subunits. These observations indicate that TAN-1C may directly engage NF-kappa B transcription factors and modulate nuclear gene expression.

Full Text

The Full Text of this article is available as a PDF (1.0M).

Articles from The Journal of Experimental Medicine are provided here courtesy of The Rockefeller University Press