BRG1 (Brahma-Related Gene 1), encoded by SMARCA4, is the ATPase subunit of the SWI/SNF (SWItch/Sucrose Non-Fermentable) chromatin remodeling complex. This complex uses the energy of ATP hydrolysis to slide, evict, or restructure nucleosomes, dynamically regulating DNA accessibility for transcription, DNA repair, and replication. BRG1 is essential for development, neuronal differentiation, and synaptic plasticity, and its dysfunction has been implicated in Alzheimer's disease, Parkinson's disease, and cancer. [1]
BRG1 protein is the central catalytic engine of the SWI/SNF complex, one of the most important epigenetic regulators in eukaryotes. The SWI/SNF complex remodels chromatin by altering nucleosome positions, thereby controlling access to DNA for transcription factors, DNA repair machinery, and the transcriptional machinery. BRG1-containing complexes regulate thousands of genes, with particular importance in neuronal development and function. [2]
| Property | Value |
|---|---|
| Protein Name | BRG1 (SMARCA4) |
| Gene | SMARCA4 |
| UniProt ID | P51532 |
| PDB ID | 6EFA, 6GRG |
| Molecular Weight | 185 kDa |
| Subcellular Localization | Nucleus (chromatin-associated) |
| Protein Family | SNF2 superfamily, SWI/SNF family |
| Aliases | BRG1, SNF2L4, BAF190, SMARCA4 |
BRG1 contains characteristic domains:
The ATPase domain adopts a bipartite structure typical of chromatin remodelers, with a hinge region allowing conformational changes during the remodeling cycle.
BRG1 in the nervous system:
BRG1/SMARCA4 dysfunction in AD:
BRG1 involvement in PD:
SMARCA2 (BRM, BRG1's paralog) mutations cause Rett-like syndrome:
SMARCA4 is a major tumor suppressor:
Hu et al. BRG1 in neurodegeneration, J Neurosci (2020). 2020. ↩︎
D'Alessio et al. CBX7 in aging and cancer, Aging Cell (2018). 2018. ↩︎