Hydroxyphenylation of Histone Lysines: Post-translational Modification by Quinone Imines
| Autor: | Paul L. Skipper, Laura J. Trudel, Gerald N. Wogan, John S. Wishnok, Steven R. Tannenbaum, Kodihalli C. Ravindra |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Models Molecular Lysine CHO Cells Tandem mass spectrometry Aminophenols 01 natural sciences Biochemistry Article Histones 03 medical and health sciences chemistry.chemical_compound Residue (chemistry) Cricetulus Cricetinae Animals Amino Acid Sequence biology Autoxidation Chemistry Chinese hamster ovary cell 010401 analytical chemistry Quinones General Medicine Hydrogen Peroxide 0104 chemical sciences Quinone 030104 developmental biology Histone biology.protein Molecular Medicine Imines Protein Processing Post-Translational DNA |
| Popis: | Monocyclic aromatic amines are widespread environmental contaminants with multiple sources such as combustion products, pharmaceuticals, and pesticides. Their phenolic metabolites are converted intracellularly to electrophilic quinone imines upon autoxidation and can embed in the cellular matrix through a transimination reaction that leaves a redox-active residue as a substituent of lysine side-chain amino groups. To demonstrate the occurrence of this process within the cellular nucleus, Chinese hamster ovary AA8 cells were treated with the para-phenol of 3,5-dimethylamine, after which the histone proteins were isolated, derivatized, and subjected to tryptic digestion. The resulting peptides were analyzed by tandem mass spectrometry to determine which lysines were modified. Nine residues in histones H2A, H2B, and H4 were identified; these were located in histone tails, close to where DNA makes contact with the nuclear core particle, elsewhere on the protein surface, and deep within the core. Kinetics of disappearance of the modified lysines in cultured cells was determined using isotope-dilution mass spectrometry. AA8 cells were also transfected with the genetically encoded hydrogen peroxide biosensor HyPer in constructs that lead to expression of HyPer in different cellular compartments. Challenging the resulting cells with the dimethylaminophenol resulted in sustained fluorescence emission in each of the compartments, demonstrating ongoing production of H2O2. The kinetics of modified lysine loss determined by mass spectrometry was consistent with persistence of HyPer fluorescence emission. We conclude that the para-phenol of 3,5-dimethylamine can become stably integrated into the histone proteins, which are minimally repaired, if at all, and function as a persistent source of intracellular H2O2. |
| Databáze: | OpenAIRE |
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