Fiche publication
Date publication
juillet 2011
Auteurs
Membres identifiés du Cancéropôle Est :
Dr BRONNER Christian
Tous les auteurs :
Nady N, Lemak A, Walker JR, Avvakumov GV, Kareta MS, Achour M, Xue S, Duan S, Allali-Hassani A, Zuo X, Wang YX, Bronner C, Chedin F, Arrowsmith CH, Dhe-Paganon S
Lien Pubmed
Résumé
Histone modifications and DNA methylation represent two layers of heritable epigenetic information that regulate eukaryotic chromatin structure and gene activity. UHRF1 is a unique factor that bridges these two layers; it is required for maintenance DNA methylation at hemimethylated CpG sites, which are specifically recognized through its SRA domain and also interacts with histone H3 trimethylated on lysine 9 (H3K9me3) in an unspecified manner. Here we show that UHRF1 contains a tandem Tudor domain (TTD) that recognizes H3 tail peptides with the heterochromatin-associated modification state of trimethylated lysine 9 and unmodified lysine 4 (H3K4me0/K9me3). Solution NMR and crystallographic data reveal the TTD simultaneously recognizes H3K9me3 through a conserved aromatic cage in the first Tudor subdomain and unmodified H3K4 within a groove between the tandem subdomains. The subdomains undergo a conformational adjustment upon peptide binding, distinct from previously reported mechanisms for dual histone mark recognition. Mutant UHRF1 protein deficient for H3K4me0/K9me3 binding shows altered localization to heterochromatic chromocenters and fails to reduce expression of a target gene, p16(INK4A), when overexpressed. Our results demonstrate a novel recognition mechanism for the combinatorial readout of histone modification states associated with gene silencing and add to the growing evidence for coordination of, and cross-talk between, the modification states of H3K4 and H3K9 in regulation of gene expression.
Référence
J Biol Chem. 2011 Jul 8;286(27):24300-11
