Quantitative crotonylome analysis reveals that crotonylation of splicing factors is involved in DNA damage response

The DNA damage response (DDR) network comprises a range of protein factors and post-translational modifications (PTMs) that cooperate to maintain genomic stability following DNA damage. Lysine crotonylation (Kcr) is an emerging PTM, though its role in the DDR has not been thoroughly explored. We used quantitative proteomics to identify global Kcr substrates and assess their changes in response to DNA damage. Our results revealed 593 Kcr sites on 360 proteins that increased by more than 1.5-fold, while 331 Kcr sites on 233 proteins decreased by more than 0.67-fold following etoposide-induced DNA damage. Alterations in Kcr levels particularly in RNA splicing factors were most markedly pronounced before and after DNA damage. This study presents the first Kcr proteome regulated during the DDR and highlights the potential critical role of RNA-related factors in this process.