Proteome-wide analysis and functional identification of lysine β-hydroxybutyrylation in Ustilaginoidea virens

Lysine β-hydroxybutyrylation (Kbhb) is an evolutionarily conserved and widespread post-translational modification (PTM) in active gene transcription and cellular proliferation. However, its function remains unknown in phytopathogenic fungi. Here, we report a comprehensive identification of Kbhb in the rice false smut fungus Ustilaginoidea virens. Total 2,204 Kbhb sites were identified in 852 proteins. We found that β-hydroxybutyrylated proteins were enriched in mannose type O-glycan biosynthesis, citrate cycle (TCA cycle), ribosome, glycolysis/gluconeogenesis, proteasome, glyoxylate and dicarboxylate metabolism, alanine, aspartate and glutamate metabolism, pyruvate metabolism, biosynthesis of nucleotide sugars, butanoate metabolism, arginine biosynthesis, fructose and mannose metabolism, propanoate metabolism, methane metabolism, fatty acid degradation, β-alanine metabolism, valine, leucine and isoleucine degradation, phagosome, oxidative phosphorylation pathway. This suggests Kbhb might be involved in basic life functions of Ustilaginoidea virens.