SWI/SNF chromatin remodeling controls Notch-responsive enhancer accessibility.
Notch signaling plays a key role in many cell fate decisions during development by directing different gene expression programs via the transcription factor CSL, known as Su(H) in Drosophila Which target genes are responsive to Notch signaling is influenced by the chromatin state of enhancers, yet how this is regulated is not fully known. Detecting a specific increase in the histone variant H3.3 in response to Notch signaling, we tested which chromatin remodelers or histone chaperones are required for the changes in enhancer accessibility to Su(H) binding. We show a crucial role for the Brahma SWI/SNF chromatin remodeling complex, including the actin-related BAP55 subunit, in conferring enhancer accessibility and enabling the transcriptional response to Notch activity. The Notch-responsive regions have high levels of nucleosome turnover which depend on the Brahma complex, increase in magnitude with Notch signaling, and primarily involve histone H3.3. Together these results highlight the importance of SWI/SNF-mediated nucleosome turnover in rendering enhancers responsive to Notch.
['Pillidge|Zoe|Z|', 'Bray|Sarah J|SJ|0000-0002-1642-599X']
D000107:Acetylation D000818:Animals D002843:Chromatin D042002:Chromatin Assembly and Disassembly D002868:Chromosomal Proteins, Non-Histone D004330:Drosophila D029721:Drosophila Proteins D005786:Gene Expression Regulation D006657:Histones D009707:Nucleosomes D051880:Receptors, Notch D012045:Regulatory Sequences, Nucleic Acid D014157:Transcription Factors D014158:Transcription, Genetic
SWI/SNF Notch Drosophila nucleosome turnover histone H3.3