Comprehensive Profiling for Histone H4 of Human Liver Cells Using High Resolution LTQ‐Orbitrap Mass Spectrometry

Abstract

The post translational modifications of histone variants are playing an important role in the structure of chromatin, the regulation of gene activities and the diagnosis of diseases, and conducting in-depth researches and discovering new sites depend on new and rational analytical methods to some extent. In this work, the combinatorial method of high resolution LTQ-Orbitrap mass spectrometry and multiple enzymes was employed to identify the post translational modifications (PTMs) of histone H4 of human liver cells. The novel methylation site, argnine 67 (R 67), was observed besides some sites reported previously such as lysine 31 (K 31), lysine 44 (K 44), argnine 55 (R 55) and lysine 59 (K 59) in the global domain. Meanwhile, various combinations of acetylation of lysine 5 (K 5), lysine 8 (K 8), lysine 12 (K 12), lysine 16 (K 16) and methylation of lysine 20 (K 20) in the NH 2 -terminal tails were also identified after the LC-MS/MS analysis of trypsin, Arg-C, Glu-C and chymotrypsin digests.

Quantitative Profiling of Histone H3 Methylation in Human Hepatocellular Carcinoma

“…Histone methylation has close pathological links with various types of cancer, such as breast cancer, lung cancer, chronic lymphocytic leukemia and other diseases [15]. In recent years, substantial progress has been made in understanding the molecular pathogenesis of HCC (hepatocellular carcinoma) corresponding to histone modifications [16][17][18]. Epigenetic silencing of tumor suppressor genes in HCC is generally mediated by DNA hypermethylation of CpG island promoters and histone modifications such as histone deacetylation, methylation of histone H3 lysine 9 (H3K9) and tri-methylation of H3K27 [19].…”