Abstract
The RAG1/RAG2 endonuclease initiates V(D)J recombination at antigen receptor loci but also binds to thousands of places outside of these loci. RAG2 localizes directly to lysine 4 trimethylated histone 3 (H3K4me3) through a plant homeodomain (PHD) finger. The relative contribution of RAG2-dependent and RAG1-intrinsic mechanisms in determining RAG1 binding patterns is not known. Through analysis of deep RAG1 ChIP-seq data, we provide a quantitative description of the forces underlying genome-wide targeting of RAG1. Surprisingly, sequence-specific DNA binding contributes minimally to RAG1 targeting outside of antigen receptor loci. Instead, RAG1 binding is driven by two distinct modes of interaction with chromatin: the first is driven by H3K4me3, promoter-focused and dependent on the RAG2 PHD, and the second is defined by H3K27Ac, enhancer-focused and dependent on 'non-core' portions of RAG1. Based on this and additional chromatin and genomic features, we formulated a predictive model of RAG1 targeting to the genome. RAG1 binding sites predicted by our model correlate well with observed patterns of RAG1-mediated breaks in human pro-B acute lymphoblastic leukemia. Overall, this study provides an integrative model for RAG1 genome-wide binding and off-target activity and reveals a novel role for the RAG1 non-core region in RAG1 targeting.
Original language | English |
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Pages (from-to) | 9624-9637 |
Number of pages | 14 |
Journal | Nucleic Acids Research |
Volume | 44 |
Issue number | 20 |
DOIs | |
State | Published - 16 Nov 2016 |
Externally published | Yes |
Bibliographical note
Publisher Copyright:© The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.
Funding
The authors wish to thank Yoram Louzoun and Gilad Liberman for valuable insight and advice regarding computational approaches used in this study, and to Lindsay Cowell and Min Kim for genome-wide RSS scanning. National Institutes of Health [R37 AI32524 to D.G.S.]; NRSA Institutional Postdoctoral Training Grant [T32 AI007019]; Cancer Research Institute Irvington Postdoctoral Fellowship [to G.T]. Funding for open access charge: National Institutes of Health [R37 AI32524 to D.G.S.]. D.G.S. is an investigator of the Howard Hughes Medical Institute. Conflict of interest statement. None declared.
Funders | Funder number |
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National Institutes of Health | |
Howard Hughes Medical Institute | |
National Institute of Allergy and Infectious Diseases | R37AI032524 |
Cancer research institute | |
Israel National Road Safety Authority | T32 AI007019 |