Enzymes catalyzing CpG methylation in DNA, including DNMT1 and DNMT3A/B, are indispensable for mammalian tissue development and homeostasis 1-4. They are also implicated in human developmental disorders and cancers 5-8 , supporting a critical role of DNA methylation during cell fate specification and maintenance. Recent studies suggest that histone posttranslational modifications (PTMs) are involved in specifying patterns of DNMT localization and DNA methylation at promoters and actively transcribed gene bodies 9-11. However, mechanisms governing the establishment and maintenance of intergenic DNA methylation remain poorly understood. Germline mutations in DNMT3A define Tatton-Brown-Rahman syndrome (TBRS), a
Background: Plant homeodomain (PHD) fingers are central "readers" of histone post-translational modifications (PTMs) with > 100 PHD finger-containing proteins encoded by the human genome. Many of the PHDs studied to date bind to unmodified or methylated states of histone H3 lysine 4 (H3K4). Additionally, many of these domains, and the proteins they are contained in, have crucial roles in the regulation of gene expression and cancer development. Despite this, the majority of PHD fingers have gone uncharacterized; thus, our understanding of how these domains contribute to chromatin biology remains incomplete. Results: We expressed and screened 123 of the annotated human PHD fingers for their histone binding preferences using reader domain microarrays. A subset (31) of these domains showed strong preference for the H3 N-terminal tail either unmodified or methylated at H3K4. These H3 readers were further characterized by histone peptide microarrays and/or AlphaScreen to comprehensively define their H3 preferences and PTM cross-talk. Conclusions: The high-throughput approaches utilized in this study establish a compendium of binding information for the PHD reader family with regard to how they engage histone PTMs and uncover several novel reader domainhistone PTM interactions (i.e., PHRF1 and TRIM66). This study highlights the usefulness of high-throughput analyses of histone reader proteins as a means of understanding how chromatin engagement occurs biochemically.
Bromodomains exhibit preferences
for specific patterns of post-translational
modifications on core and variant histone proteins. We examined the
ligand specificity of the ATAD2B bromodomain and compared it to its
closely related paralogue in ATAD2. We show that the ATAD2B bromodomain
recognizes mono- and diacetyllysine modifications on histones H4 and
H2A. A structure–function approach was used to identify key
residues in the acetyllysine-binding pocket that dictate the molecular
recognition process, and we examined the binding of an ATAD2 bromodomain
inhibitor by ATAD2B. Our analysis demonstrated that critical contacts
required for bromodomain inhibitor coordination are conserved between
the ATAD2/B bromodomains, with many residues playing a dual role in
acetyllysine recognition. We further characterized an alternative
splice variant of ATAD2B that results in a loss of function. Our results
outline the structural and functional features of the ATAD2B bromodomain
and identify a novel mechanism regulating the interaction of the ATAD2B
protein with chromatin.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.