Elucidating pBAF-complex functions by chemical genetics and epigenome editing

Abstract The eukaryotic genome is highly organized within the nucleus, controlling many cellular processes. Chromatin regulators set up, erase, and maintain chromatin states and organizational patterns to control gene expression, pluripotency, differentiation, and development. One class of chromatin regulators, the mSWI/SNF family, comprises three main complexes in stem cells, canonical BAF (cBAF), polybromo-associated BAF (pBAF), and GLITSCR-associated BAF (gBAF). The three forms share common subunits, but each also has distinct subunits. How these complexes differ in function and specificity and the contribution of the unique subunits needs to be better elucidated. We will determine these differences by focusing on separating pBAF complex functions and specificity. We will define the roles of pBAF complexes using loss-of-function and gain-of-function studies. Biochemical and genomics approaches using degradable alleles and mutant histone lines will allow us to determine transcription and chromatin changes when these complexes are lost. Using an inducible dCas9- based targeted recruitment strategy that I developed, we will determine transcription and chromatin changes mediated by these complexes when they are gained at a new site in the genome. Since chromatin dysregulation can lead to various human diseases, including developmental and neurological diseases and cancer, understanding normal and dysfunctional mechanisms of chromatin regulation is of great importance to human health.