ACTL6B
Function
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 (By similarity). Essential for neuronal maturation and dendrite development (PubMed:31031012).
Involvement in disease
Developmental and epileptic encephalopathy 76
DEE76
A form of epileptic encephalopathy, a heterogeneous group of severe early-onset epilepsies characterized by refractory seizures, neurodevelopmental impairment, and poor prognosis. Development is normal prior to seizure onset, after which cognitive and motor delays become apparent. DEE76 is an autosomal recessive form that may result in death in childhood.
None
The disease is caused by variants affecting the gene represented in this entry.
Intellectual developmental disorder with severe speech and ambulation defects
IDDSSAD
An autosomal dominant neurodevelopmental disorder with onset in infancy, and characterized by global developmental delay, intellectual disability, ambulation deficits, severe language impairment, and minor dysmorphic features including a wide mouth, diastema, and bulbous nose. Additional manifestations are spasticity, hypotonia and autistic features including stereotypies. Brain imaging show thin corpus callosum, generalized atrophy, and mild periventricular gliosis.
None
The disease is caused by variants affecting the gene represented in this entry.
Sequence Similarities
Belongs to the actin family.
Cellular localization
- Nucleus
Alternative names
ACTL6, BAF53B, ACTL6B, Actin-like protein 6B, 53 kDa BRG1-associated factor B, Actin-related protein Baf53b, ArpNalpha, BRG1-associated factor 53B