6nq3
Crystal Structure of a SUZ12-RBBP4-PHF19-JARID2 Heterotetrameric ComplexCrystal Structure of a SUZ12-RBBP4-PHF19-JARID2 Heterotetrameric Complex
Structural highlights
Disease[SUZ12_HUMAN] A chromosomal aberration involving SUZ12 may be a cause of endometrial stromal tumors. Translocation t(7;17)(p15;q21) with JAZF1. The translocation generates the JAZF1-SUZ12 oncogene consisting of the N-terminus part of JAZF1 and the C-terminus part of SUZ12. It is frequently found in all cases of endometrial stromal tumors, except in endometrial stromal sarcomas, where it is rarer.[1] Function[JARD2_HUMAN] Regulator of histone methyltransferase complexes that plays an essential role in embryonic development, including heart and liver development, neural tube fusion process and hematopoiesis. Acts by modulating histone methyltransferase activity and promoting the recruitment of histone methyltransferase complexes to their target genes. Binds DNA and mediates the recruitment of the PRC2 complex to target genes in embryonic stem cells. Does not have histone demethylase activity but regulates activity of various histone methyltransferase complexes. In embryonic stem cells, it associates with the PRC2 complex and inhibits trimethylation of 'Lys-27' of histone H3 (H3K27me3) by the PRC2 complex, thereby playing a key role in differentiation of embryonic stem cells and normal development. In cardiac cells, it is required to repress expression of cyclin-D1 (CCND1) by activating methylation of 'Lys-9' of histone H3 (H3K9me) by the GLP1/EHMT1 and G9a/EHMT2 histone methyltransferases. Also acts as a transcriptional repressor of ANF via its interaction with GATA4 and NKX2-5. Participates in the negative regulation of cell proliferation signaling.[2] [RBBP4_HUMAN] Core histone-binding subunit that may target chromatin assembly factors, chromatin remodeling factors and histone deacetylases to their histone substrates in a manner that is regulated by nucleosomal DNA. Component of several complexes which regulate chromatin metabolism. These include the chromatin assembly factor 1 (CAF-1) complex, which is required for chromatin assembly following DNA replication and DNA repair; the core histone deacetylase (HDAC) complex, which promotes histone deacetylation and consequent transcriptional repression; the nucleosome remodeling and histone deacetylase complex (the NuRD complex), which promotes transcriptional repression by histone deacetylation and nucleosome remodeling; the PRC2/EED-EZH2 complex, which promotes repression of homeotic genes during development; and the NURF (nucleosome remodeling factor) complex.[3] [PHF19_HUMAN] Polycomb group (PcG) that specifically binds histone H3 trimethylated at 'Lys-36' (H3K36me3) and recruits the PRC2 complex. Probably involved in the transition from an active state to a repressed state in embryonic stem cells: acts by binding to H3K36me3, a mark for transcriptional activation, and recruiting H3K36me3 histone demethylases NO66 or KDM2B, leading to demethylation of H3K36 and recruitment of the PRC2 complex that mediates H3K27me3 methylation, followed by de novo silencing. Recruits the PRC2 complex to CpG islands and contributes to embryonic stem cell self-renewal. Also binds dimethylated at 'Lys-36' (H3K36me2). Isoform 1 and isoform 2 inhibit transcription from an HSV-tk promoter.[4] [5] [6] [7] [SUZ12_HUMAN] Polycomb group (PcG) protein. Component of the PRC2/EED-EZH2 complex, which methylates 'Lys-9' (H3K9me) and 'Lys-27' (H3K27me) of histone H3, leading to transcriptional repression of the affected target gene. The PRC2/EED-EZH2 complex may also serve as a recruiting platform for DNA methyltransferases, thereby linking two epigenetic repression systems. Genes repressed by the PRC2/EED-EZH2 complex include HOXC8, HOXA9, MYT1 and CDKN2A.[8] [9] [10] [11] [12] [13] Publication Abstract from PubMedDiverse accessory subunits are involved in the recruitment of polycomb repressive complex 2 (PRC2) to CpG island (CGI) chromatin. Here we report the crystal structure of a SUZ12-RBBP4 complex bound to fragments of the accessory subunits PHF19 and JARID2. Unexpectedly, this complex adopts a dimeric structural architecture, accounting for PRC2 self-association that has long been implicated. The intrinsic PRC2 dimer is formed via domain swapping involving RBBP4 and the unique C2 domain of SUZ12. MTF2 and PHF19 associate with PRC2 at around the dimer interface and stabilize the dimer. Conversely, AEBP2 binding results in a drastic movement of the C2 domain, disrupting the intrinsic PRC2 dimer. PRC2 dimerization enhances CGI DNA binding by PCLs in pairs in vitro, reminiscent of the widespread phenomenon of transcription factor dimerization in active transcription. Loss of PRC2 dimerization impairs histone H3K27 trimethylation (H3K27me3) on chromatin at developmental gene loci in mouse embryonic stem cells. A Dimeric Structural Scaffold for PRC2-PCL Targeting to CpG Island Chromatin.,Chen S, Jiao L, Liu X, Yang X, Liu X Mol Cell. 2020 Jan 13. pii: S1097-2765(19)30949-9. doi:, 10.1016/j.molcel.2019.12.019. PMID:31959557[14] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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