Tudor, MBT and chromo domains gauge the degree of lysine methylation

Abstract

The post-translational modification of histones regulates many cellular processes, including transcription, replication and DNA repair. A large number of combinations of post-translational modifications are possible. This cipher is referred to as the histone code. Many of the enzymes that lay down this code have been identified. However, so far, few code-reading proteins have been identified. Here, we describe a protein-array approach for identifying methyl-specific interacting proteins. We found that not only chromo domains but also tudor and MBT domains bind to methylated peptides from the amino-terminal tails of histones H3 and H4. Binding specificity observed on the protein-domain microarray was corroborated using peptide pull-downs, surface plasma resonance and far western blotting. Thus, our studies expose tudor and MBT domains as new classes of methyl-lysinebinding protein modules, and also demonstrates that proteindomain microarrays are powerful tools for the identification of new domain types that recognize histone modifications.

SIRT 7 promotes genome integrity and modulates non‐homologous end joining DNA repair

“…It will be interesting to investigate whether this regulation occurs through a direct interaction between 53BP1 and histone H3 deacetylated at K18. Since the 53BP1 tudor domain seems not to recognize histone H3 tail (Kim et al , 2006), other domains should be involved in the direct interaction of H3K18 and 53BP1. Nevertheless, our results show that SIRT7‐mediated H3K18 deacetylation at chromatin flanking DSBs constitutes a novel pathway that facilitates the recruitment of 53BP1, which adds to the previously described chromatin features required for efficient 53BP1 binding to sites of DNA damage.…”

Identifying novel proteins recognizing histone modifications using peptide pull-down assay

“…Finally, I point out that principals underlying the peptdide pull-down assay described here may be modified to screen immobilized peptide libraries for histone peptide readers in a high throughput, more automated format. A reverse approach with protein array containing immobilized GST fusion proteins probed with different methylated peptides has already been described [15]. Schematics of the peptide pull-down assay.…”

Histone H4 lysine 20 monomethylation promotes transcriptional repression by L3MBTL1

“…The chromodomains of HP1 (Jacobs and Khorasanizadeh, 2002) and CHD1 (Flanagan et al, 2005;Pray-Grant et al, 2005), and the tudor domains of JMJD2A (Huang et al, 2006), bind preferentially to trimethylated lysines, but also interact with lower methylation states (mono-and di-). In contrast, the tudor domain of 53BP1, can discriminate between the di-and trimethyl state of H4K20, preferring the dimethyl form (Botuyan et al, 2006;Kim et al, 2006). Tudor and chromodomains are members of a conserved 'Royal' family of motifs and are related to PWWP, Agenet and MBT domains (Maurer-Stroh et al, 2003).…”