Brahma Associated Factor Complex in development and disease

Abstract

Chromatin accessibility, especially the process of nucleosome eviction is critical for geneactivation in eukaryotic cells. The Brahma-associated Factor (BAF) complex plays a key role in creating accessible chromatin at gene promoters enhancers in an ATP-dependent manner and by direct binding to DNA and nucleosomes In Chapter 2, I study the importance of BAF in a developmental context by testing the interdependence of ecdysone-receptor transcription factor binding with BAF ATPase nucleosome remodeling activity for gene activation during ecdysoneinduced metamorphosis in Drosophila melanogaster. To measure changes in the chromatin landscape, I use a chromatin profiling technology developed in our lab, Cleavage Under Targets & Tagmentation (CUT&Tag), which allows mapping of targets genome-wide. Furthermore I use a version for targeting Accessible Chromatin (CUTAC), which maps RNA Polymerase IIassociated DNA accessibility genome-wide In Chapter 3, I test the use of BAF-inhibitors in a triple-negative breast cancer cell-line in combination with the cyclin dependent kinase 12, CDK12, transcriptional kinase inhibitor. I measure the chromatin changes underlying observed synergy in cell cytotoxicity and cell-death in MDA-MB-231 cells treated with both FHT1015 BAF inhibitor and THZ531 CDK12 inhibition. The combined treatment leads to loss of chromatin and DNA integrity, supporting apoptosis. My work elucidates the importance of ATPdependent BAF activity with transcription factor binding in normal development and highlights the utility of BAF loss of function as a cancer-killing strategies