A transcriptional coactivator cooperating with nuclear hormone receptors to potentiate transcriptional activation. SMARCA2 / BRM belongs to the SNF2/RAD54 helicase family，is a homologue of the Saccharomyces cerevisiae SWI2/SNF2 and Drosophila brahma proteins. It contains a methyl lysine containing bromo domain and an HSA domain. The yeast protein SNF2，also known as SWI2，is involved in transcriptional activation of numerous genes. It contains a domain that is highly conserved among several known helicases and is required for transcriptional activity. SNF2/SWI2 is highly homologous to the Drosophila protein 'brahma' (brm). Although the 2 proteins show nuclear localization during interphase，they are excluded from the condensed chromosomes during mitosis. They found that the level of BRM，but not BRG1，was strongly reduced during mitosis. Phosphorylation of hbrm and BRG1 did not disrupt their association with SNF5 but correlated with a decreased affinity for the nuclear structure in early M phase.