New lysine-acetylated proteins screened by immunoaffinity and liquid chromatography-mass spectrometry

Abstract

The lack of selective extraction specific for lysine-acetylated proteins has been a major problem in the field of acetylation biology, though acetylation plays a key role in many biological processes. In this paper, we report for the first time the proteomic screening of lysine-acetylated proteins from a mouse liver tissue, by a new approach of immunoaffinity purification of lysine-acetylated peptides combined with nano-HPLC/MS/MS analysis. We have found 20 lysine-acetylated proteins with 21 lysine- acetylated sites, among which 12 lysine-acetylated proteins and 16 lysine-acetylated sites have never been reported before. Notably, three acetyltransferases harboring in mitochondrion are newly discovered acetyltransferases responsible for the acetylation of nonhistone proteins. We have explored the significant patterns of residue preference by the hierarchical clustering analysis of amino acid residues surrounding acetylation sites, which could be helpful to the prediction of new sites of lysine acetylation. Our findings provide more candidates for studying the important roles played by acetylation in diverse cellular pathways and related human diseases.