A Method for Systematic Mapping of Protein Lysine Methylation Identifies Functions for HP1 beta in DNA Damage Response

作者：Liu Huadong; Galka Marek; Mori Eiichiro; Liu Xuguang; Lin Yu fen; Wei Ran; Pittock Paula; Voss Courtney; Dhami Gurpreet; Li Xing; Miyaji Masaaki; Lajoie Gilles; Chen Benjamin; Li Shawn Shun Cheng^*

来源：Molecular Cell, 2013, 50(5): 723-735.

DOI：10.1016/j.molcel.2013.04.025

Lysine methylation occurs on both histone and nonhistone proteins. However, our knowledge on the prevalence and function of nonhistone protein methylation is poor. We describe an approach that combines peptide array, bioinformatics, and mass spectrometry to systematically identify lysine methylation sites and map methyllysine-driven protein-protein interactions. Using this approach, we identified a high-confidence and high-resolution interactome of the heterochromatin protein 1 beta (HP1 beta) and uncovered, simultaneously, numerous methyllysine sites on nonhistone proteins. We found that HP1 beta binds to DNA-dependent protein kinase catalytic subunit (DNA-PKcs) and regulates its localization to double-strand breaks (DSBs) during DNA damage response (DDR). Mutation of the methylation sites in DNA-PKcs or depletion of HP1 beta in cells caused defects in DDR. Furthermore, we showed that the methylation of DNA-PKcs and many other proteins in the HP1 beta interactome undergoes large changes in response to DNA damage, indicating that Lys methylation is a highly dynamic posttranslational modification.

• 出版日期2013-6-6