Global Lysine Crotonylation Profiling of Mouse Liver.

Lysine crotonylation (Kcr) is a recently discovered post-translational modification that potentially regulates multiple biological processes. With an objective to expand the available crotonylation datasets, we performed LC-MS/MS using mouse liver samples under normal physiological conditions to obtain in vivo crotonylome. We used a label-free strategy and identified 10,034 Class I (localization probabilities > 0.75) crotonylated sites in 2,245 proteins. The KcrE, KcrD, and EKcr motifs were significantly enriched in the crotonylated peptides. The identified crotonylated proteins were mostly enzymes and primarily located in the cytoplasm and nucleus. Functional enrichment analysis based on Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) showed that the crotonylated proteins were closely related to the purine-containing compound metabolic process, ribose phosphate metabolic process, carbon metabolism pathway, ribosome pathway, and a series of metabolism-associated biological processes. To the best of our knowledge, this research provides the first report on the mouse liver crotonylome. Furthermore, it offers additional evidence that crotonylation exists in non-histone proteins, and is likely involved in various biological processes. The mass spectrometry proteomics data have been deposited in the ProteomeXchange Consortium with the dataset identifiers PXD019145. This article is protected by copyright. All rights reserved.