6uch
From Proteopedia
SMARCB1 nucleosome-interacting C-terminal alpha helix
Structural highlights
Disease[SNF5_HUMAN] Neurofibromatosis type 3;Atypical teratoid rhabdoid tumor;Familial rhabdoid tumor;Familial multiple meningioma;Coffin-Siris syndrome. The disease is caused by mutations affecting the gene represented in this entry. Disease susceptibility is associated with variations affecting the gene represented in this entry. The disease is caused by mutations affecting the gene represented in this entry. Function[SNF5_HUMAN] Core component of the BAF (hSWI/SNF) complex. This ATP-dependent chromatin-remodeling complex plays 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 would be 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/BRG1/BAF190A. 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 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 (By similarity). Plays a key role in cell-cycle control and causes cell cycle arrest in G0/G1.[1] [2] [3] [4] [5] [6] Publication Abstract from PubMedMammalian switch/sucrose non-fermentable (mSWI/SNF) complexes are multi-component machines that remodel chromatin architecture. Dissection of the subunit- and domain-specific contributions to complex activities is needed to advance mechanistic understanding. Here, we examine the molecular, structural, and genome-wide regulatory consequences of recurrent, single-residue mutations in the putative coiled-coil C-terminal domain (CTD) of the SMARCB1 (BAF47) subunit, which cause the intellectual disability disorder Coffin-Siris syndrome (CSS), and are recurrently found in cancers. We find that the SMARCB1 CTD contains a basic alpha helix that binds directly to the nucleosome acidic patch and that all CSS-associated mutations disrupt this binding. Furthermore, these mutations abrogate mSWI/SNF-mediated nucleosome remodeling activity and enhancer DNA accessibility without changes in genome-wide complex localization. Finally, heterozygous CSS-associated SMARCB1 mutations result in dominant gene regulatory and morphologic changes during iPSC-neuronal differentiation. These studies unmask an evolutionarily conserved structural role for the SMARCB1 CTD that is perturbed in human disease. Recurrent SMARCB1 Mutations Reveal a Nucleosome Acidic Patch Interaction Site That Potentiates mSWI/SNF Complex Chromatin Remodeling.,Valencia AM, Collings CK, Dao HT, St Pierre R, Cheng YC, Huang J, Sun ZY, Seo HS, Mashtalir N, Comstock DE, Bolonduro O, Vangos NE, Yeoh ZC, Dornon MK, Hermawan C, Barrett L, Dhe-Paganon S, Woolf CJ, Muir TW, Kadoch C Cell. 2019 Nov 27;179(6):1342-1356.e23. doi: 10.1016/j.cell.2019.10.044. Epub, 2019 Nov 20. PMID:31759698[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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Categories: Human | Large Structures | Dhe-Paganon, S | Kadoch, C | Mashtalir, N | Seo, H S | Sun, Z Y.J | Valencia, A M | Vangos, H S | Yeoh, Z C | Alpha helix | Arginine cluster | Baf complex | Baf47 | Chromatin remodeling | Mswi-snf complex | Nuclear protein | Nucleosome binding | Positive charge cluster | Smarcb1
