PHF1 (PHD finger protein 1) is a subunit of the major epigenetic complex, PRC2 (Polycomb repressive complex-2), essential in gene regulation and implicated in cancer and developmental disorders. The methyltransferase activity of PRC2, which is directed at lysine 27 of histone H3, promotes transcriptional repression; however the role of PHF1 in the complex remains unclear. PHF1 contains a unique combination of a Tudor domain fused with a plant homeodomain finger 1 (PHD1) followed by a second PHD2 finger. Our recent studies demonstrate that Tudor recognizes histone H3K36me3, whereas PHD1 binds EZH2, and PHD2 associates with DNA. The molecular mechanisms underlying these novel functions of PHF1 are unknown and will be elucidated in the proposed studies. Detailed knowledge of these mechanisms is of fundamental importance for understanding the physiological and pathogenic activities of PRC2. We hypothesize that binding of the PHD2 finger of PHF1 to DNA stabilizes PHF1 at chromatin, whereas recognition of H3K36me3 by Tudor restricts methyltransferase activity of the PHF1/PRC2 complex. We seek to understand the molecular basis and functional significance of the interactions of PHF1 with chromatin. To determine the mechanism of histone and DNA recognition, the atomic-resolution structures of the PHF1 domains bound to their ligands will be obtained by NMR spectroscopy or X-ray crystallography. Formation of the PHF1-nucleosome complex will be characterized using electrophoretic mobility shift assay (EMSA), NMR and Frster Resonance Energy Transfer (FRET). The mutant proteins impaired in histone or DNA binding activities will be tested in vitro and in vivo by immunoprecipitation, Western blot analysis, ChIP, and histone methyltransferase assays to define the importance of PHF1 in PRC2-dependent transcriptional repression and regulation of histone methylation. These studies will shed light on the role of PHF1 in biological activities of the vital PRC2 complex, allowing us to build a model of signaling by PHF1/PRC2, and will lead to a better understanding of the epigenetic mechanisms of gene transcription.

Public Health Relevance

PHF1 is a subunit of the major repressive complex PRC2 that plays a key role in gene transcription and is found dysregulated in cancer and developmental disorders. The proposed studies will lead to a better understanding of how the PHF1/PRC2 signaling pathways can be therapeutically manipulated and may help to develop new strategies to prevent or treat malignancies and developmental diseases.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
3R01GM106416-02S1
Application #
9272156
Study Section
Program Officer
Preusch, Peter
Project Start
2015-05-01
Project End
2019-03-31
Budget Start
2016-04-01
Budget End
2017-03-31
Support Year
2
Fiscal Year
2016
Total Cost
$51,273
Indirect Cost
$18,300
Name
University of Colorado Denver
Department
Pharmacology
Type
Schools of Medicine
DUNS #
041096314
City
Aurora
State
CO
Country
United States
Zip Code
80045
Klein, Brianna J; Krajewski, Krzysztof; Restrepo, Susana et al. (2018) Recognition of cancer mutations in histone H3K36 by epigenetic writers and readers. Epigenetics 13:683-692
Klein, Brianna J; Vann, Kendra R; Andrews, Forest H et al. (2018) Structural insights into the ?-?-? stacking mechanism and DNA-binding activity of the YEATS domain. Nat Commun 9:4574
Klein, Brianna J; Ahmad, Salar; Vann, Kendra R et al. (2018) Yaf9 subunit of the NuA4 and SWR1 complexes targets histone H3K27ac through its YEATS domain. Nucleic Acids Res 46:421-430
Zhang, Yi; Mun, Su Ran; Linares, Juan F et al. (2018) ZZ-dependent regulation of p62/SQSTM1 in autophagy. Nat Commun 9:4373
Zhang, Yi; Kutateladze, Tatiana G (2018) Diet and the epigenome. Nat Commun 9:3375
Zhang, Yi; Xue, Yongming; Shi, Jiejun et al. (2018) The ZZ domain of p300 mediates specificity of the adjacent HAT domain for histone H3. Nat Struct Mol Biol 25:841-849
Mi, Wenyi; Zhang, Yi; Lyu, Jie et al. (2018) The ZZ-type zinc finger of ZZZ3 modulates the ATAC complex-mediated histone acetylation and gene activation. Nat Commun 9:3759
Vann, Kendra R; Kutateladze, Tatiana G (2018) Architecture of PRC2 Holo Complexes. Trends Biochem Sci 43:487-489
Brown, David A; Di Cerbo, Vincenzo; Feldmann, Angelika et al. (2017) The SET1 Complex Selects Actively Transcribed Target Genes via Multivalent Interaction with CpG Island Chromatin. Cell Rep 20:2313-2327
Gibson, Matthew D; Gatchalian, Jovylyn; Slater, Andrew et al. (2017) PHF1 Tudor and N-terminal domains synergistically target partially unwrapped nucleosomes to increase DNA accessibility. Nucleic Acids Res 45:3767-3776

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