A coordinated phosphorylation cascade initiated by p38MAPK/MSK1 directs RARalpha to target promoters.
Fiche publication
Date publication
janvier 2009
Auteurs
Membres identifiés du Cancéropôle Est :
Dr ROCHETTE-EGLY Cécile
Tous les auteurs :
Bruck N, Vitoux D, Ferry C, Duong V, Bauer A, de The H, Rochette-Egly C
Lien Pubmed
Résumé
The nuclear retinoic acid (RA) receptor alpha (RARalpha) is a transcriptional transregulator that controls the expression of specific gene subsets through binding at response elements and dynamic interactions with coregulators, which are coordinated by the ligand. Here, we highlighted a novel paradigm in which the transcription of RARalpha target genes is controlled by phosphorylation cascades initiated by the rapid RA activation of the p38MAPK/MSK1 pathway. We demonstrate that MSK1 phosphorylates RARalpha at S369 located in the ligand-binding domain, allowing the binding of TFIIH and thereby phosphorylation of the N-terminal domain at S77 by cdk7/cyclin H. MSK1 also phosphorylates histone H3 at S10. Finally, the phosphorylation cascade initiated by MSK1 controls the recruitment of RARalpha/TFIIH complexes to response elements and subsequently RARalpha target gene activation. Cancer cells characterized by a deregulated p38MAPK/MSK1 pathway, do not respond to RA, outlining the essential contribution of the RA-triggered phosphorylation cascade in RA signalling.
Référence
EMBO J. 2009 Jan 7;28(1):34-47