First comprehensive proteome analysis of lysine crotonylation in Streptococcus agalactiae, a pathogen causing meningoencephalitis in teleosts

BACKGROUD: Streptococcus agalactiae is a common colonizer of the rectovaginal tract and lead to infectious diseases of neonatal and non-pregnant adults, which also causes infectious disease in fish and a zoonotic risk as well. Lysine crotonylation (Kcr) is a kind of histone post-translational modifications discovered in 2011. In yeast and mammals, Kcr function as potential enhancers and promote gene expression. However, lysine crotonylation in S. agalactiae has not been studied yet. METHODS: In this study, the crotonylation profiling of fish pathogen, S. agalactiae was investigated by combining affinity enrichment with LC MS/MS. The Kcr modification of several selected proteins were further validated by Western blotting. RESULTS: In the present study, we conducted the proteome-wide profiling of Kcr in S. agalactiae and identified 241 Kcr sites from 675 screened proteins for the first time. Bioinformatics analysis showed that 164 sequences were matched to a total of six definitively conserved motifs, and many of them were significantly enriched in metabolic processes, cellular process, and single-organism processes. Moreover, four crotonylation modified proteins were predicted as virulence factors or to being part of the quorum sensing system PTMs on bacteria. The data are available via ProteomeXchange with identifier PXD026445. CONCLUSIONS: These data provide a promising starting point for further functional research of crotonylation in bacterial virulence in S. agalactiae. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12953-021-00182-y.