SMARCA4
SMARCA4, also known as BRG1, BAF190 or hSNF2b, is the ATPase subunit of SWI/SNF chromatin remodelling complexes. It uses ATP hydrolysis to alter DNA-histone contacts within nucleosomes, activating or repressing select genes. Browse Assay Genie's current range of SMARCA4 research reagents below, or read on for the biology behind the target.
SMARCA4 is an ATPase involved in transcriptional activation and repression of select genes by chromatin remodelling, meaning alteration of DNA-nucleosome topology. It is a component of SWI/SNF complexes, which change chromatin structure by altering DNA-histone contacts within a nucleosome in an ATP-dependent manner. The complex is required for transcriptional activation of genes normally repressed by chromatin. SMARCA4 also binds RNA in a promiscuous manner.
In neurons, SMARCA4 is part of the CREST-BRG1 complex, which regulates promoter activation through calcium-dependent release of a repressor complex and recruitment of an activator complex. At the resting c-FOS promoter, SMARCA4-dependent recruitment of a phospho-RB1-HDAC repressor complex inhibits transcription. Calcium influx leads calcineurin to dephosphorylate RB1, releasing the repressor, while CREBBP is recruited in a CREST-dependent manner. SMARCA4 is also found in the neural progenitor (npBAF) and neuron-specific (nBAF) complexes, whose subunit exchange accompanies the shift from proliferating stem cells to postmitotic neurons. It may promote neural stem cell self-renewal by enhancing Notch-dependent proliferative signals. Elsewhere, it acts as a corepressor of ZEB1 at the E-cadherin promoter, is required for ZEB1-induced epithelial-mesenchymal transition, and contributes to thermogenic gene expression in brown adipose tissue.
The SMARCA4 gene encodes a member of the SNF2/RAD54 helicase family, similar to Drosophila brahma, with helicase and ATPase activities. The protein can bind BRCA1 and regulates expression of CD44. HGNC groups it with bromodomain-containing proteins and with BAF, PBAF and GBAF complex subunits. Mutations in the gene cause rhabdoid tumour predisposition syndrome type 2, and multiple transcript variants encode different isoforms. Other names include SNF2L4, SNF2-beta and SWI2.
SMARCA4 supplies the ATPase activity that changes DNA-histone contacts in nucleosomes, making it central to studies of how chromatin structure controls gene expression.
SMARCA4 sits in npBAF and nBAF complexes and the CREST-BRG1 complex, linking chromatin remodelling to neural stem cell renewal and dendrite growth.
SMARCA4 corepresses ZEB1 to regulate E-cadherin transcription and is required for ZEB1-induced EMT, a process relevant to cell state transitions.
Mutations in SMARCA4 cause rhabdoid tumour predisposition syndrome type 2, and the protein binds BRCA1 and regulates CD44 expression.
SMARCA4 is the ATPase of SWI/SNF chromatin remodelling complexes. It alters DNA-histone contacts within nucleosomes in an ATP-dependent manner, thereby activating or repressing select genes. It also contributes to neuronal gene regulation, ZEB1-driven E-cadherin repression and thermogenic gene expression in brown adipose tissue.
Yes. BRG1 is the best-known alias of SMARCA4. Other names include BAF190, hSNF2b, SNF2-beta, SNF2L4, SNF2LB, SNF2 and SWI2. The older HGNC name described it as a SWI/SNF related, matrix associated, actin dependent regulator of chromatin, subfamily a, member 4.
Mouse and rat both have a Smarca4 ortholog. In humans, mutations in SMARCA4 cause rhabdoid tumour predisposition syndrome type 2. Check the datasheet of any product for its validated reactivity.
Other SWI/SNF-related chromatin remodelling ATPases with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt P51532; product specifications from Assay Genie datasheets.