Abstract：

In the eukaryotic nucleus, DNA is packaged with histone and non-histone proteins to form a highly organized chromatin structure. This DNA-protein assembly can represent a significant barrier to a number of nuclear processes such as DNA repair, recombination, replication and transcription.A number of chromatin remodeling complexes have been identified that modulate the arrangement and stability of nucleosomes via the covalent modification of histone proteins.Often the structural changes in chromatin that accompany transcriptional activation require multi-protein enzymatic complexes that manipulate the nucleosomal architecture.Alteration in the chromatin structure by ATP-dependent remodeling complexes is considered a significant initial step in transcriptional regulation.The mammalian SWI/SNF remodeling complex has been shown to play important roles in gene expression by altering local chromatin structure and recruiting transcription factors to sequence-specific DNA.BRG1, the central ATPase of the human SWI/SNF-like BAF complex, is critical for numerous biological functions including nuclear receptor signaling.Analysis of BRG1 mutants suggests functional motifs outside the ATPase domain are important for transcriptional activity.