@article{1299948,

title = {Interaction with the DNA Repair Protein Thymine DNA Glycosylase Regulates Histone Acetylation by p300},

author = {Ryan A Henry and Pietro Mancuso and Yin-Ming Kuo and Rossella Tricarico and Marc Tini and Philip A Cole and Alfonso Bellacosa and Andrew J Andrews},

doi = {10.1021/acs.biochem.6b00841},

issn = {1520-4995},

year  = {2016},

date = {2016-12-01},

journal = {Biochemistry},

volume = {55},

number = {49},

pages = {6766-6775},

abstract = {How protein-protein interactions regulate and alter histone modifications is a major unanswered question in epigenetics. The histone acetyltransferase p300 binds thymine DNA glycosylase (TDG); utilizing mass spectrometry to measure site-specific changes in histone acetylation, we found that the absence of TDG in mouse embryonic fibroblasts leads to a reduction in the rate of histone acetylation. We demonstrate that TDG interacts with the CH3 domain of p300 to allosterically promote p300 activity to specific lysines on histone H3 (K18 and K23). However, when TDG concentrations approach those of histones, TDG acts as a competitive inhibitor of p300 histone acetylation. These results suggest a mechanism for how histone acetylation is fine-tuned via interaction with other proteins, while also highlighting a connection between regulators of two important biological processes: histone acetylation and DNA repair/demethylation.},

keywords = {Acetylation, Animals, Cell Line, Cells, Cultured, DNA Repair, E1A-Associated p300 Protein, Histones, Knockout, Mice, Thymine DNA Glycosylase},

pubstate = {published},

tppubtype = {article}

}

@article{1299967,

title = {Histone deacetylase inhibitors decrease NHEJ both by acetylation of repair factors and trapping of PARP1 at DNA double-strand breaks in chromatin},

author = {Carine Robert and Pratik K Nagaria and Nisha Pawar and Adeoluwa Adewuyi and Ivana Gojo and David J Meyers and Philip A Cole and Feyruz V Rassool},

doi = {10.1016/j.leukres.2016.03.007},

issn = {1873-5835},

year  = {2016},

date = {2016-06-01},

journal = {Leuk Res},

volume = {45},

pages = {14-23},

abstract = {Histone deacetylase inhibitors (HDACi) induce acetylation of histone and non-histone proteins, and modulate the acetylation of proteins involved in DNA double-strand break (DSB) repair. Non-homologous end-joining (NHEJ) is one of the main pathways for repairing DSBs. Decreased NHEJ activity has been reported with HDACi treatment. However, mechanisms through which these effects are regulated in the context of chromatin are unclear. We show that pan-HDACi, trichostatin A (TSA), causes differential acetylation of DNA repair factors Ku70/Ku80 and poly ADP-ribose polymerase-1 (PARP1), and impairs NHEJ. Repair effects are reversed by treatments with p300/CBP inhibitor C646, with significantly decreased acetylation of PARP1. In keeping with these findings, TSA treatment significantly increases PARP1 binding to DSBs in chromatin. Notably, AML patients treated with HDACi entinostat (MS275) in vivo also show increased formation of poly ADP-ribose (PAR) that co-localizes with DSBs. Further, we demonstrate that PARP1 bound to chromatin increases with duration of TSA exposure, resembling PARP "trapping". Knockdown of PARP1 inhibits trapping and mitigates HDACi effects on NHEJ. Finally, combination of HDACi with potent PARP inhibitor talazoparib (BMN673) shows a dose-dependent increase in PARP "trapping", which correlates with increased apoptosis. These results provide a mechanism through which HDACi inhibits deacetylation and increases binding of PARP1 to DSBs, leading to decreased NHEJ and cytotoxicity of leukemia cells.},

keywords = {Acetylation, Acute, Benzamides, Chromatin, Cultured, DNA Breaks, DNA End-Joining Repair, Double-Stranded, Histone Deacetylase Inhibitors, Humans, Ku Autoantigen, Leukemia, Myeloid, Poly (ADP-Ribose) Polymerase-1, Pyridines, Tumor Cells},

pubstate = {published},

tppubtype = {article}

}

@article{1299963,

title = {Modulation of p300/CBP Acetylation of Nucleosomes by Bromodomain Ligand I-CBP112},

author = {B. E. Zucconi and B. Luef and W. Xu and R. A. Henry and I. M. Nodelman and G. D. Bowman and A. J Andrews and P. A. Cole},

doi = {10.1021/acs.biochem.6b00480},

issn = {1520-4995},

year  = {2016},

date = {2016-00-00},

journal = {Biochemistry},

volume = {55},

number = {27},

pages = {3727-34},

abstract = {The histone acetyltransferase (HAT) enzymes p300 and CBP are closely related paralogs that serve as transcriptional coactivators and have been found to be dysregulated in cancer and other diseases. p300/CBP is a multidomain protein and possesses a highly conserved bromodomain that has been shown to bind acetylated Lys residues in both proteins and various small molecules, including I-CBP112 and CBP30. Here we show that the ligand I-CBP112 can stimulate nucleosome acetylation up to 3-fold while CBP30 does not. Activation of p300/CBP by I-CBP112 is not observed with the isolated histone H3 substrate but requires a nucleosome substrate. I-CBP112 does not impact nucleosome acetylation by the isolated p300 HAT domain, and the effects of I-CBP112 on p300/CBP can be neutralized by CBP30, suggesting that I-CBP112 likely allosterically activates p300/CBP through bromodomain interactions. Using mass spectrometry and Western blots, we have found that I-CBP112 particularly stimulates acetylation of Lys18 of histone H3 (H3K18) in nucleosomes, an established in vivo site of p300/CBP. In addition, we show that I-CBP112 enhances H3K18 acetylation in acute leukemia and prostate cancer cells in a concentration range commensurate with its antiproliferative effects. Our findings extend the known pharmacology of bromodomain ligands in the regulation of p300/CBP and suggest a novel approach to modulating histone acetylation in cancer.},

keywords = {Acetylation, Bromine Compounds, Cell Proliferation, Crystallography, Cultured, E1A-Associated p300 Protein, Histones, Humans, Leukemia, Male, Models, Molecular, Mutagenesis, Nucleosomes, p300-CBP Transcription Factors, Prostatic Neoplasms, Protein Binding, Protein Conformation, Site-Directed, Tumor Cells, X-Ray},

pubstate = {published},

tppubtype = {article}

}

@article{1299973,

title = {Protein lysine acetylation by p300/CBP},

author = {Beverley M Dancy and Philip A Cole},

doi = {10.1021/cr500452k},

issn = {1520-6890},

year  = {2015},

date = {2015-03-01},

journal = {Chem Rev},

volume = {115},

number = {6},

pages = {2419-52},

keywords = {Acetylation, Animals, Humans, Lysine, Models, Molecular, p300-CBP Transcription Factors},

pubstate = {published},

tppubtype = {article}

}

@article{1299977,

title = {Regulation of S-adenosylhomocysteine hydrolase by lysine acetylation},

author = {Yun Wang and Jennifer M Kavran and Zan Chen and Kannan R Karukurichi and Daniel J Leahy and Philip A Cole},

doi = {10.1074/jbc.M114.597153},

issn = {1083-351X},

year  = {2014},

date = {2014-11-01},

journal = {J Biol Chem},

volume = {289},

number = {45},

pages = {31361-72},

abstract = {S-Adenosylhomocysteine hydrolase (SAHH) is an NAD(+)-dependent tetrameric enzyme that catalyzes the breakdown of S-adenosylhomocysteine to adenosine and homocysteine and is important in cell growth and the regulation of gene expression. Loss of SAHH function can result in global inhibition of cellular methyltransferase enzymes because of high levels of S-adenosylhomocysteine. Prior proteomics studies have identified two SAHH acetylation sites at Lys(401) and Lys(408) but the impact of these post-translational modifications has not yet been determined. Here we use expressed protein ligation to produce semisynthetic SAHH acetylated at Lys(401) and Lys(408) and show that modification of either position negatively impacts the catalytic activity of SAHH. X-ray crystal structures of 408-acetylated SAHH and dually acetylated SAHH have been determined and reveal perturbations in the C-terminal hydrogen bonding patterns, a region of the protein important for NAD(+) binding. These crystal structures along with mutagenesis data suggest that such hydrogen bond perturbations are responsible for SAHH catalytic inhibition by acetylation. These results suggest how increased acetylation of SAHH may globally influence cellular methylation patterns.},

keywords = {Acetylation, Adenosylhomocysteinase, Amino Acid, Amino Acid Sequence, Catalysis, Crystallography, Humans, Hydrogen Bonding, Lysine, Methylation, Models, Molecular, Molecular Sequence Data, Mutagenesis, NAD, Plasmids, Post-Translational, Protein Binding, Protein Processing, Protein Structure, Recombinant Proteins, Sequence Homology, Site-Directed, Structure-Activity Relationship, Tertiary, X-Ray},

pubstate = {published},

tppubtype = {article}

}