A comprehensive atlas of lysine acetylome in onion thrips (Thrips tabaci Lind.) revealed by proteomics analysis

Abstract

Protein lysine acetylation is a reversible posttranslational modification and plays a pivotal role in a broad array of physiological functions. In our study, a strategy combining immunoaffinity enrichment of acetylated peptides based on anti-acetyllysine antibody with high-resolution tandem mass spectrometry was employed for a systemic survey of acetylation sites in a polyphagous pest insect Thrips tabaci. In total, 597 acetylated proteins containing 995 lysine acetylation sites were identified in T. tabaci. Interestingly, functional enrichment analysis showed that acetylated proteins are implicated in the regulation of diverse KEGG pathways, including carbohydrate metabolism, energy metabolism, amino acid metabolism, and translational process. In particular, a large fraction of metabolic enzymes, including multiple rate-limiting enzymes, was also found to be acetylated. Comparative analysis indicated that a proportion of euNOG entries was shared by three insects. Furthermore, motif analysis showed that the sequence flanking acetylation sites exhibited subcellular compartment-specific patterns. Protein-protein interaction network analysis demonstrated that acetylated proteins formed several densely connected sub-networks tightly associated with ribosome, fatty acid metabolism, oxidative phosphorylation and purine metabolism, thus strengthening the functional enrichment result. Overall, our study provides a comprehensive view of acetylation sites, facilitating an in-depth investigation of functional roles of acetylation in the future. SignificanceOnion thrips is a polyphagous agricultural pest insect. Insecticide resistance has been frequently reported due to the intensive use of chemical pesticides. Lysine acetylation is a ubiquitous posttranslational modification and plays important roles in gene regulation. An in-depth understanding of transcriptional regulation is crucial for designing novel and highly efficient pesticides. With high-resolution mass spectrometry based proteomics method, we systematically explored the acetylome in this insect. In total, 595 proteins containing 995 acetylation sites were identified in this study. Bioinformatic analysis revealed that acetylated proteins are implicated in regulating diverse biological processes, including carbohydrate metabolism, energy metabolism, amino acid metabolism, and translational process. Furthermore, protein-protein interaction network analysis showed that ribosome, fatty acid metabolism, oxidative metabolism and purine metabolism are significantly enriched for acetylated proteins. Our results provide insights into the targets of acetylation in onion thrips and facilitate elucidation of transcriptional regulation and design of novel control strategies against this insect.