Establishment of a newly improved detection system for NF-κB activity

The transcription factor nuclear factor-kappa B (NF-kappa B) plays roles in apoptosis, inflammation and oncogenesis. It is important for biological and medical research to understand when proteins of interest are activated in cells, leading to the establishment of a luciferase/EGFP assay to monitor the activation of transcription factors. Here, we describe an improved reporter system for NF-kappa B, the NF-kappa B-activated transgene (NAT) system that can detect NF-kappa B signalling with high sensitivity and specificity. The NAT system consists of large copy numbers of NF-kappa B consensus sequence and a minimal promoter derived from the mouse interleukin-2 (IL-2) gene. Furthermore, we generated NAT systems with stable or unstable luciferase/EGFP proteins. Stable and unstable types of luciferase/EGFP are suitable for analyzing the accumulation of and the real-time activity of NF-kappa B signal, respectively. Our findings suggest that the NAT system is effective for in vivo imaging of NF-kappa B signalling using cells or animals. (c) 2007 Elsevier B.V. All rights reserved.