Synonyms:ATP dependent helicase SMARCA4, BAF190, BAF190A, BRG1, BRG1 associated factor 190A, FLJ39786, hSNF2b, Protein brahma homolog 1, Protein BRG 1, SMARCA4, SNF2, SNF2 BETA, SNF2B, SNF2L4, SNF2LB, SWI2, Transcription activator BRG1 Background:SMARCA4, also named as BAF190A, BRG1, SNF2B and SNF2L4, belongs to the SNF2/RAD54 helicase family. SMARCA4 is a transcriptional coactivator cooperating with nuclear hormone receptors to potentiate transcriptional activation. It is a component of the CREST-BRG1 complex, a multiprotein complex that regulates promoter activation by orchestrating a calcium-dependent release of a repressor complex and a recruitment of an activator complex. It is also involved in vitamin D-coupled transcription regulation via its association with the WINAC complex, a chromatin-remodeling complex recruited by vitamin D receptor(VDR), which is required for the ligand-bound VDR-mediated transrepression of the CYP27B1 gene.