Transcription Activator BRG1 (SMARCA4) Human Recombinant Protein

The protein encoded by this gene is a member of the SWI/SNF family of proteins and is similar to the brahma protein of Drosophila. Members of this family have helicase and ATPase activities and are thought to regulate transcription of certain genes by altering the chromatin structure around those genes. The encoded protein is part of the large ATP-dependent chromatin remodeling complex SNF/SWI, which is required for transcriptional activation of genes normally repressed by chromatin. In addition, this protein can bind BRCA1, as well as regulate the expression of the tumorigenic protein CD44. Mutations in this gene cause rhabdoid tumor predisposition syndrome type 2. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, May 2012]

SMARCA4: a member of the SWI/SNF nucleosome remodeling complex with ATP-dependent DNA helicase activity. SWI/SNF complexes are required for mammalian development and are mutated in ~20% of all human primary tumors. Mutated in 35% (13/37) of NSCLC and 5% (1/19) of SCLC human lung cancer cell lines . 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. Belongs to the neural progenitor-specific chromatin remodeling complex (npBAF complex) and the neuron-specific chromatin remodeling complex (nBAF complex). Component of the BAF53 complex which acetylates histone H4 and H2A within nucleosomes. Transcriptional coactivator of nuclear hormone receptors. Acts as a corepressor of ZEB1 to regulate E-cadherin transcription, and is required for induction of epithelial-mesenchymal transition (EMT) by ZEB1. Can bind BRCA1, as well as regulate the expression of the tumorigenic protein CD44. SMARCA4, in consort with ZEB1, represses the transcription of E-cadherin and promotes the epithelial-to-mesenchymal transisition (EMT). SMARCA4 is required for stem cell maintenance in the mouse intestinal epithelium. Its loss inhibits aberrant Wnt-signalling and prevents tumorigenesis in the mouse small intestine. SMARCA4 mutations are the cause of a familial cancer syndrome predisposing to renal or extrarenal malignant rhabdoid tumors and to a variety of tumors of the central nervous system, including choroid plexus carcinoma, medulloblastoma, and central primitive neuroectodermal tumors. Rhabdoid tumors are the most aggressive and lethal malignancies occurring in early childhood. Belongs to the SNF2/RAD54 helicase family. The human protein includes 5 isoforms produced by alternative splicing.

Protein type: EC 3.6.1.-; Nuclear receptor co-regulator; EC 3.6.4.-; Transcription, coactivator/corepressor; Helicase; Tumor suppressor; Cell cycle regulation

Chromosomal Location of Human Ortholog: 19p13.2

Cellular Component: extracellular space; membrane; nuclear chromatin; nucleolus; nucleoplasm; nucleus; protein complex; SWI/SNF complex

Molecular Function: androgen receptor binding; ATP binding; DNA-dependent ATPase activity; helicase activity; nucleosomal DNA binding; p53 binding; protein binding; protein N-terminus binding; Tat protein binding; transcription coactivator activity; transcription corepressor activity; transcription factor binding

Biological Process: ATP-dependent chromatin remodeling; chromatin remodeling; establishment and/or maintenance of chromatin architecture; negative regulation of cell growth; negative regulation of transcription from RNA polymerase II promoter; negative regulation of transcription from RNA polymerase II promoter, mitotic; negative regulation of transcription, DNA-dependent; nervous system development; nucleosome disassembly; positive regulation of transcription factor activity; positive regulation of transcription from RNA polymerase II promoter; positive regulation of transcription, DNA-dependent; positive regulation of Wnt receptor signaling pathway; regulation of transcription from RNA polymerase II promoter; spermatid development; transcription, DNA-dependent

Disease: Mental Retardation, Autosomal Dominant 16; Rhabdoid Tumor Predisposition Syndrome 2