SMARCB1 Antibody – Rabbit Polyclonal

The protein encoded by this gene is part of a complex that relieves repressive chromatin structures, allowing the transcriptional machinery to access its targets more effectively. The encoded nuclear protein may also bind to and enhance the DNA joining activity of HIV-1 integrase. This gene has been found to be a tumor suppressor, and mutations in it have been associated with malignant rhabdoid tumors. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

SMARCB1: a core component of the BAF (hSWI/SNF) complex. This family of complexes remodels chromatin structures, enabling transcription factors to gain access to DNA. They play important roles in cell proliferation and differentiation, in cellular antiviral activities and inhibition of tumor formation. The BAF complex is able to create a stable, altered form of chromatin that constrains fewer negative supercoils than normal. This change in supercoiling is due to the conversion of up to one-half of the nucleosomes on polynucleosomal arrays into asymmetric structures, termed altosomes, each composed of 2 histones octamers. Stimulates in vitro the remodeling activity of SMARCA4. Involved in activation of CSF1 promoter. Belongs to the neural progenitors- specific chromatin remodeling complex (npBAF complex) and the neuron-specific chromatin remodeling complex (nBAF complex). During neural development a switch from a stem/progenitor to a post-mitotic 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 post-mitotic 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 BAF53A and PHF10, are exchanged for homologous alternative BAF53B and BAF45B or 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. Plays a key role in cell-cycle control and causes cell cycle arrest in G0/G1. Also involved in vitamin D-coupled transcription regulation via its association with the WINAC complex, a chromatin-remodeling complex recruited by vitamin D receptor (VDR), which is required for the ligand- bound VDR-mediated transrepression of the CYP27B1 gene. Component of the BAF (hSWI/SNF) complex, which includes at least actin (ACTB), ARID1A, ARID1B, SMARCA2, SMARCA4, BAF53A, BAF53B, SMARCE1 SMARCC1, SMARCC2, SMARCB1, and one or more of SMARCD1, SMARCD2, or SMARCD3. In muscle cells, the BAF complex also contains DPF3. Component of the WINAC complex, at least composed of SMARCA2, SMARCA4, SMARCB1, SMARCC1, SMARCC2, SMARCD1, SMARCE1, ACTL6A, WSTF, ARID1A, SUPT16H, CHAF1A and TOP2B. Binds to double-stranded DNA. Interacts with EphB4 and MAEL. Interacts with GADD34. Binds tightly to the human immunodeficiency virus-type 1 (HIV-1) integrase in vitro and stimulates its DNA-joining activity. Interacts with human papillomavirus 18 E1 protein to stimulates its viral replication. Belongs to the SNF5 family. 2 isoforms of the human protein are produced by alternative splicing.

Protein type: Tumor suppressor; Transcription, coactivator/corepressor; Cell cycle regulation

Chromosomal Location of Human Ortholog: 22q11.23|22q11

Cellular Component: XY body; nucleoplasm; SWI/SNF complex; protein complex; nuclear chromatin; nucleolus; nucleus

Molecular Function: protein binding; nucleosomal DNA binding; Tat protein binding; p53 binding; transcription coactivator activity

Biological Process: nervous system development; establishment and/or maintenance of chromatin architecture; transcription, DNA-dependent; DNA integration; DNA repair; chromatin remodeling; regulation of transcription from RNA polymerase II promoter; negative regulation of cell proliferation; nucleosome disassembly; blastocyst hatching; ATP-dependent chromatin remodeling; positive regulation of transcription from RNA polymerase II promoter; positive regulation of transcription factor activity; cell differentiation

Disease: Mental Retardation, Autosomal Dominant 15; Rhabdoid Tumor Predisposition Syndrome 1; Schwannomatosis 1