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From Proteopedia
NMR structure of UHRF1 Tandem Tudor Domains in a complex with Spacer peptide
Structural highlights
DiseaseUHRF1_HUMAN Note=Defects in UHRF1 may be a cause of cancers. Overexpressed in many different forms of human cancers, including bladder, breast, cervical, colorectal and prostate cancers, as well as pancreatic adenocarcinomas, rhabdomyosarcomas and gliomas. Plays an important role in the correlation of histone modification and gene silencing in cancer progression. Expression is associated with a poor prognosis in patients with various cancers, suggesting that it participates in cancer progression. FunctionUHRF1_HUMAN Multidomain protein that acts as a key epigenetic regulator by bridging DNA methylation and chromatin modification. Specifically recognizes and binds hemimethylated DNA at replication forks via its YDG domain and recruits DNMT1 methyltransferase to ensure faithful propagation of the DNA methylation patterns through DNA replication. In addition to its role in maintenance of DNA methylation, also plays a key role in chromatin modification: through its tudor-like regions and PHD-type zinc fingers, specifically recognizes and binds histone H3 trimethylated at 'Lys-9' (H3K9me3) and unmethylated at 'Arg-2' (H3R2me0), respectively, and recruits chromatin proteins. Enriched in pericentric heterochromatin where it recruits different chromatin modifiers required for this chromatin replication. Also localizes to euchromatic regions where it negatively regulates transcription possibly by impacting DNA methylation and histone modifications. Has E3 ubiquitin-protein ligase activity by mediating the ubiquitination of target proteins such as histone H3 and PML. It is still unclear how E3 ubiquitin-protein ligase activity is related to its role in chromatin in vivo. May be involved in DNA repair.[1] [2] [3] [4] [5] [6] [7] [8] [9] Publication Abstract from PubMedUHRF1 is an important epigenetic regulator for maintenance DNA methylation. UHRF1 recognizes hemi-methylated DNA (hm-DNA) and trimethylation of histone H3K9 (H3K9me3), but the regulatory mechanism remains unknown. Here we show that UHRF1 adopts a closed conformation, in which a C-terminal region (Spacer) binds to the tandem Tudor domain (TTD) and inhibits H3K9me3 recognition, whereas the SET-and-RING-associated (SRA) domain binds to the plant homeodomain (PHD) and inhibits H3R2 recognition. Hm-DNA impairs the intramolecular interactions and promotes H3K9me3 recognition by TTD-PHD. The Spacer also facilitates UHRF1-DNMT1 interaction and enhances hm-DNA-binding affinity of the SRA. When TTD-PHD binds to H3K9me3, SRA-Spacer may exist in a dynamic equilibrium: either recognizes hm-DNA or recruits DNMT1 to chromatin. Our study reveals the mechanism for regulation of H3K9me3 and hm-DNA recognition by URHF1. Hemi-methylated DNA opens a closed conformation of UHRF1 to facilitate its histone recognition.,Fang J, Cheng J, Wang J, Zhang Q, Liu M, Gong R, Wang P, Zhang X, Feng Y, Lan W, Gong Z, Tang C, Wong J, Yang H, Cao C, Xu Y Nat Commun. 2016 Apr 5;7:11197. doi: 10.1038/ncomms11197. PMID:27045799[10] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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