TAF4, a subunit of transcription factor II D, directs promoter occupancy of nuclear receptor HNF4A during post-natal hepatocyte differentiation.
Fiche publication
Date publication
janvier 2014
Auteurs
Membres identifiés du Cancéropôle Est :
Dr DAVIDSON Irwin, Dr ROMIER Christophe
Tous les auteurs :
Alpern D, Langer D, Ballester B, Le Gras S, Romier C, Mengus G, Davidson I
Lien Pubmed
Résumé
The functions of the TAF subunits of mammalian TFIID in physiological processes remain poorly characterised. In this study, we describe a novel function of TAFs in directing genomic occupancy of a transcriptional activator. Using liver-specific inactivation in mice, we show that the TAF4 subunit of TFIID is required for post-natal hepatocyte maturation. TAF4 promotes pre-initiation complex (PIC) formation at post-natal expressed liver function genes and down-regulates a subset of embryonic expressed genes by increased RNA polymerase II pausing. The TAF4-TAF12 heterodimer interacts directly with HNF4A and in vivo TAF4 is necessary to maintain HNF4A-directed embryonic gene expression at post-natal stages and promotes HNF4A occupancy of functional cis-regulatory elements adjacent to the transcription start sites of post-natal expressed genes. Stable HNF4A occupancy of these regulatory elements requires TAF4-dependent PIC formation highlighting that these are mutually dependent events. Local promoter-proximal HNF4A-TFIID interactions therefore act as instructive signals for post-natal hepatocyte differentiation.
Référence
Elife. 2014 Sep 10;3:e03613