Artículos de revistas
Molecular Mechanisms of System Control of NF-κB Signaling by IκBα
Fecha
2010Registro en:
Ferreiro, Diego; Komives, Elizabeth A.; Molecular Mechanisms of System Control of NF-κB Signaling by IκBα
; American Chemical Society; Biochemistry; 49; 8; -1-2010; 1560-1567
0006-2960
Autor
Ferreiro, Diego
Komives, Elizabeth A.
Resumen
The NF-κB family of transcription factors responds to inflammatory cytokines with rapid transcriptional activation and subsequent signal repression. Much of the system control depends on the unique characteristics of its major inhibitor, IκBR, which appears to have folding dynamics that underlie the biophysical properties of its activity. Theoretical folding studies followed by experiments have shown that a portion of the ankyrin repeat domain of IκBR folds on binding. In resting cells, IκBR is constantly being synthesized, but most of it is rapidly degraded, leaving only a very small pool of free IκBR. Nearly all of the NF-κB is bound to IκBR, resulting in near-complete inhibition of nuclear localization and transcriptional activation. Combined solution biophysical measurements and quantitative protein half-life measurements inside cells have allowed us to understand how the inhibition occurs, why IκBR can be degraded quickly in the free state but remain extremely stable in the bound state, and how signal activation and repression can be tuned by IκB folding dynamics. This review summarizes results of in vitro and in vivo experiments that converge demonstrating the effective interplay between biophysics and cell biology in understanding transcriptional control by the NF-κB signaling module.