Recurrent SMARCB1 Mutations Reveal a Nucleosome Acidic Patch Interaction Site That Potentiates mSWI/SNF Complex Chromatin Remodeling.
Valencia, A.M., Collings, C.K., Dao, H.T., St Pierre, R., Cheng, Y.C., Huang, J., Sun, Z.Y., Seo, H.S., Mashtalir, N., Comstock, D.E., Bolonduro, O., Vangos, N.E., Yeoh, Z.C., Dornon, M.K., Hermawan, C., Barrett, L., Dhe-Paganon, S., Woolf, C.J., Muir, T.W., Kadoch, C.(2019) Cell 179: 1342-1356.e23
- PubMed: 31759698
- DOI: https://doi.org/10.1016/j.cell.2019.10.044
- Primary Citation of Related Structures:
6UCH - PubMed Abstract:
Mammalian 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 α 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.
Organizational Affiliation:
Department of Pediatric Oncology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA 02215, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Chemical Biology Program, Harvard University, Cambridge, MA 02138, USA.