The PZP Domain of AF10 Senses Unmodified H3K27 to Regulate DOT1L-Mediated Methylation of H3K79.
Publication Type:Journal Article
Source:Mol Cell, Volume 60, Issue 2, p.319-27 (2015)
Keywords:Binding Sites, Carcinogenesis, Cell Line, Tumor, Chromatin, Crystallography, X-Ray, Gene Expression Regulation, Leukemic, Histones, Humans, Hydrogen Bonding, Leukocytes, Lysine, Methylation, Methyltransferases, Models, Molecular, Protein Binding, Protein Interaction Domains and Motifs, Signal Transduction, Transcription Factors
<p>AF10, a DOT1L cofactor, is required for H3K79 methylation and cooperates with DOT1L in leukemogenesis. However, the molecular mechanism by which AF10 regulates DOT1L-mediated H3K79 methylation is not clear. Here we report that AF10 contains a "reader" domain that couples unmodified H3K27 recognition to H3K79 methylation. An AF10 region consisting of a PHD finger-Zn knuckle-PHD finger (PZP) folds into a single module that recognizes amino acids 22-27 of H3, and this interaction is abrogated by H3K27 modification. Structural studies reveal that H3 binding triggers rearrangement of the PZP module to form an H3(22-27)-accommodating channel and that the unmodified H3K27 side chain is encased in a compact hydrogen-bond acceptor-lined cage. In cells, PZP recognition of H3 is required for H3K79 dimethylation, expression of DOT1L-target genes, and proliferation of DOT1L-addicted leukemic cells. Together, our results uncover a pivotal role for H3K27-via readout by the AF10 PZP domain-in regulating the cancer-associated enzyme DOT1L. </p>