Proteome-Wide Analysis of Lysine 2-Hydroxyisobutyrylation in the Phytopathogenic Fungus Botrytis cinerea

Posttranslational modifications (PTMs) of the whole proteome have become a hot topic in the research field of epigenetics, and an increasing number of PTM types have been identified and shown to play significant roles in different cellular processes. Protein lysine 2-hydroxyisobutyrylation (K(hib)) is a newly detected PTM, and the 2-hydroxyisobutyrylome has been identified in several species. Botrytis cinerea is recognized as one of the most destructive pathogens due to its broad host distribution and very large economic losses; thus the many aspects of its pathogenesis have been continuously studied. However, distribution and function of K(hib) in this phytopathogenic fungus are not clear. In this study, a proteome-wide analysis of K(hib) in B. cinerea was performed, and 5,398 K(hib) sites on 1,181 proteins were identified. Bioinformatics analysis showed that the 2-hydroxyisobutyrylome in B. cinerea contains both conserved proteins and novel proteins when compared with K(hib) proteins in other species. Functional classification, functional enrichment and protein interaction network analyses showed that K(hib) proteins are widely distributed in cellular compartments and involved in diverse cellular processes. Significantly, 37 proteins involved in different aspects of regulating the pathogenicity of B. cinerea were detected as K(hib) proteins. Our results provide a comprehensive view of the 2-hydroxyisobutyrylome and lay a foundation for further studying the regulatory mechanism of K(hib) in both B. cinerea and other plant pathogens.