ACTL6B, Actin-like protein 6B
Also Known as
ACL6B_HUMAN, ACTL6B, ACTL6, BAF53B
Involved in transcriptional activation and repression of select genes by chromatin remodeling (alteration of DNA-nucleosome topology). Component of SWI/SNF chromatin remodeling complexes that carry out key enzymatic activities, changing chromatin structure by altering DNA-histone contacts within a nucleosome in an ATP-dependent manner. Belongs to the neuron-specific chromatin remodeling complex (nBAF complex), as such plays a role in remodeling mononucleosomes in an ATP-dependent fashion, and is required for postmitotic neural development and dendritic outgrowth. During neural development a switch from a stem/progenitor to a postmitotic chromatin remodeling mechanism occurs as neurons exit the cell cycle and become committed to their adult state. The transition from proliferating neural stem/progenitor cells to postmitotic neurons requires a switch in subunit composition of the npBAF and nBAF complexes. As neural progenitors exit mitosis and differentiate into neurons, npBAF complexes which contain ACTL6A/BAF53A and PHF10/BAF45A, are exchanged for homologous alternative ACTL6B/BAF53B and DPF1/BAF45B or DPF3/BAF45C subunits in neuron-specific complexes (nBAF). The npBAF complex is essential for the self-renewal/proliferative capacity of the multipotent neural stem cells. The nBAF complex along with CREST plays a role regulating the activity of genes essential for dendrite growth. ACTL6B/BAF53B is not essential for assembly of the nBAF complex but is required for targeting the complex and CREST to the promoter of genes essential for dendritic growth. Component of the multiprotein chromatin-remodeling complexes SWI/SNF: SWI/SNF-A (BAF), SWI/SNF-B (PBAF) and related complexes. The canonical complex contains a catalytic subunit (either SMARCA4/BRG1/BAF190A or SMARCA2/BRM/BAF190B) and at least SMARCE1, ACTL6A/BAF53, SMARCC1/BAF155, SMARCC2/BAF170, and SMARCB1/SNF5/BAF47. Other subunits specific to each of the complexes may also be present permitting several possible combinations developmentally and tissue specific (PubMed:22952240, PubMed:26601204). Component of the BAF complex, which includes at least actin (ACTB), ARID1A/BAF250A, ARID1B/BAF250B, SMARCA2/BRM, SMARCA4/BRG1/BAF190A, ACTL6A/BAF53, ACTL6B/BAF53B, SMARCE1/BAF57, SMARCC1/BAF155, SMARCC2/BAF170, SMARCB1/SNF5/INI1, and one or more SMARCD1/BAF60A, SMARCD2/BAF60B, or SMARCD3/BAF60C (PubMed:22952240, PubMed:26601204). Component of neuron-specific chromatin remodeling complex (nBAF complex) composed of at least, ARID1A/BAF250A or ARID1B/BAF250B, SMARCD1/BAF60A or SMARCD2/BAF60B or SMARCD3/BAF60C, SMARCA2/BRM/BAF190B, SMARCA4/BRG1/BAF190A, SMARCB1/BAF47, SMARCC1/BAF155, SMARCE1/BAF57, SMARCC2/BAF170, DPF1/BAF45B, DPF3/BAF45C, ACTL6B/BAF53B and actin (ACTB). Note that the nBAF complex is polymorphic in regard to the ATPase, SMARCA2 and SMARCA4 occupying mutually exclusive positions. May be a component of the SWI/SNF-B (PBAF) chromatin remodeling complex, at least composed of SMARCA4/BRG1, SMARCB1/BAF47/SNF5, ACTL6A/BAF53A or ACTL6B/BAF53B, SMARCE1/BAF57, SMARCD1/BAF60A, SMARCD2/BAF60B, perhaps SMARCD3/BAF60C, SMARCC1/BAF155, SMARCC2/BAF170, PBRM1/BAF180, ARID2/BAF200 and actin (PubMed:22952240, PubMed:26601204).