Fig. 5. Mutations in BAF complexes and polycomb complexes affect the balance between these two major genomic chromatin regulators.

(A) In cells without defined mutations in genes encoding BAF complex subunits, BAF and polycomb complexes oppose one another to facilitate the coordinate regulation of gene expression. (B) Upon loss-of-function (LOF) mutations, such as biallelic inactivation of hSNF5 (BAF47) in MRTs, BAF complexes lose the ability to oppose polycomb, resulting in higher overall levels and repressive histone mark placement genome-wide. (C) In specific gain-of-function (GOF) settings, such as human synovial sarcomas that contain the SS18-SSX oncogenic fusion protein, BAF complexes appear to oppose polycomb complexes at key oncogenic loci.