8qjt | pdb_00008qjt
BRM (SMARCA2) Bromodomain in complex with ligand 10
Structural highlights
DiseaseSMCA2_HUMAN Defects in SMARCA2 are the cause of Nicolaides-Baraitser syndrome (NCBRS) [MIM:601358. A rare disorder characterized by severe mental retardation with absent or limited speech, seizures, short stature, sparse hair, typical facial characteristics, brachydactyly, prominent finger joints and broad distal phalanges. Some of the features are progressive with time.[1] [2] FunctionSMCA2_HUMAN Transcriptional coactivator cooperating with nuclear hormone receptors to potentiate transcriptional activation. 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. 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 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).[3] Publication Abstract from PubMedThe identification of VHL-binding proteolysis targeting chimeras (PROTACs) that potently degrade the BRM protein (also known as SMARCA2) in SW1573 cell-based experiments is described. These molecules exhibit between 10- and 100-fold degradation selectivity for BRM over the closely related paralog protein BRG1 (SMARCA4). They also selectively impair the proliferation of the H1944 "BRG1-mutant" NSCLC cell line, which lacks functional BRG1 protein and is thus highly dependent on BRM for growth, relative to the wild-type Calu6 line. In vivo experiments performed with a subset of compounds identified PROTACs that potently and selectively degraded BRM in the Calu6 and/or the HCC2302 BRG1 mutant NSCLC xenograft models and also afforded antitumor efficacy in the latter system. Subsequent PK/PD analysis established a need to achieve strong BRM degradation (>95%) in order to trigger meaningful antitumor activity in vivo. Intratumor quantitation of mRNA associated with two genes whose transcription was controlled by BRM (PLAU and KRT80) also supported this conclusion. PROTACs Targeting BRM (SMARCA2) Afford Selective In Vivo Degradation over BRG1 (SMARCA4) and Are Active in BRG1 Mutant Xenograft Tumor Models.,Berlin M, Cantley J, Bookbinder M, Bortolon E, Broccatelli F, Cadelina G, Chan EW, Chen H, Chen X, Cheng Y, Cheung TK, Davenport K, DiNicola D, Gordon D, Hamman BD, Harbin A, Haskell R, He M, Hole AJ, Januario T, Kerry PS, Koenig SG, Li L, Merchant M, Perez-Dorado I, Pizzano J, Quinn C, Rose CM, Rousseau E, Soto L, Staben LR, Sun H, Tian Q, Wang J, Wang W, Ye CS, Ye X, Zhang P, Zhou Y, Yauch R, Dragovich PS J Med Chem. 2024 Jan 5. doi: 10.1021/acs.jmedchem.3c01781. PMID:38180485[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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