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Coactivators and general transcription factors have two distinct dynamic populations dependent on transcription
Author(s) -
Vosnakis Nikolaos,
Koch Marc,
Scheer Elisabeth,
Kessler Pascal,
Mély Yves,
Didier Pascal,
Tora László
Publication year - 2017
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.15252/embj.201696035
Subject(s) - transcription factor ii a , transcription factor ii b , transcription coregulator , biology , transcription factor ii d , rna polymerase ii , chromatin , taf1 , transcription preinitiation complex , transcription factor ii f , rna polymerase ii holoenzyme , transcription (linguistics) , microbiology and biotechnology , general transcription factor , transcription factor , genetics , promoter , chromatin remodeling , transcriptional regulation , gene expression , gene , linguistics , philosophy
SAGA and ATAC are two distinct chromatin modifying co‐activator complexes with distinct enzymatic activities involved in RNA polymerase II (Pol II ) transcription regulation. To investigate the mobility of co‐activator complexes and general transcription factors in live‐cell nuclei, we performed imaging experiments based on photobleaching. SAGA and ATAC , but also two general transcription factors ( TFIID and TFIIB ), were highly dynamic, exhibiting mainly transient associations with chromatin, contrary to Pol II , which formed more stable chromatin interactions. Fluorescence correlation spectroscopy analyses revealed that the mobile pool of the two co‐activators, as well as that of TFIID and TFIIB , can be subdivided into “fast” (free) and “slow” (chromatin‐interacting) populations. Inhibiting transcription elongation decreased H3K4 trimethylation and reduced the “slow” population of SAGA , ATAC , TFIIB and TFIID . In addition, inhibiting histone H3K4 trimethylation also reduced the “slow” populations of SAGA and ATAC . Thus, our results demonstrate that in the nuclei of live cells the equilibrium between fast and slow population of SAGA or ATAC complexes is regulated by active transcription via changes in the abundance of H3K4me3 on chromatin.