lo3 Why is remodeling important for transcription?

Why is nucleosome organization and chromatin accessibility important for gene expression?

Active genes have reduced nucleosome density at the Transcription Start Site (TSS), allowing transcription factors to bind to DNA.

What happens when the catalytic SMARCA4 subunit of BAF is knocked out in embryonic stem cells?

It leads to rapid loss of chromatin accessibility.

What is the connection between BAF-mediated accessibility and transcription factor binding?

Loss of accessibility is tightly coupled to loss of lineage-specific transcription factor binding (e.g., OCT4, SOX2).

How does the BAF complex oppose repressor function?

BAF can evict transcriptional repressors of the Polycomb family from promoters, along with their associated repressive histone modifications.

What is the general mechanism of the BAF complex in transcription?

It is responsible for chromatin remodeling and accessibility at active gene promoters and enhancers, which facilitates transcription factor binding and the eviction of repressors.

Where are the different BAF complexes enriched in the genome?

All BAF complexes overlap with accessible active regions. cBAF is specifically enriched at enhancers, while PBAF and ncBAF have a stronger preference for promote