Separation-of-function mutants reveal the NF-κB-independent involvement of IκBα in the regulation of intestinal stemness

Summary: We have previously shown that the nuclear factor κB (NF-κB) inhibitor IκBα binds chromatin together with polycomb repressor complex 2 (PRC2) to confer responsiveness to PRC2 targets in the presence of inflammatory cues. This alternative function has been elusive in both physiological and di...

Full description

Saved in:
Bibliographic Details
Main Authors: Daniel Álvarez-Villanueva, Martin Floor, Laura Solé, Luis G. Palma, María Maqueda, Joan Bertran, Teresa Lobo-Jarne, Rajani Rajbhandari, Aran Merati, Laura Marruecos, Jordi Villà-Freixa, Mar Iglesias, Markus Bredel, Anna Bigas, Lluís Espinosa
Format: Article
Language:English
Published: Elsevier 2025-07-01
Series:Cell Reports
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S221112472500720X
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Summary: We have previously shown that the nuclear factor κB (NF-κB) inhibitor IκBα binds chromatin together with polycomb repressor complex 2 (PRC2) to confer responsiveness to PRC2 targets in the presence of inflammatory cues. This alternative function has been elusive in both physiological and disease conditions because of the predominant role of IκBα as a negative regulator of NF-κB. Here, we uniquely characterize the specific residues of IκBα that allow the generation of separation-of-function (SOF) mutants that are defective for either NF-κB-related (SOFΔNF-κB) or chromatin-related (SOFΔH2A,H4) activities. Expression of IκBα SOFΔNF-κB, but not SOFΔH2A/H4, is sufficient to negatively regulate a specific stemness program in intestinal cells, thereby rescuing the differentiation block imposed by IκBα deficiency. Using a chromatin immunoprecipitation (ChIP) assay, we demonstrate that IκBα binds to several stemness genes that are transcriptionally repressed upon IκBα SOFΔNF-κB induction. Our data suggest that SOF mutants provide an exclusive tool for studying IκBα functions in physiology and disease.
ISSN:2211-1247