Development of an efficient photochemical method to specifically label and detect lysine-crotonylated (K-cr) proteins.

Abstract

Post-translational modifications (PTMs) are essential for cell survival and play an important role in regulating the biology of a cell. Lysine crotonylation (Kcr) is a recently discovered histone and non-histone PTM associated with numerous diseases, including acute kidney injury, depression, HIV latency, cardiovascular disease, and cancer. Despite the strong correlation of Kcr with multiple diseases, no chemical tools for the in-depth study of this PTM are available yet. Kcr contains an electron-rich α,β-unsaturated bond, representing an excellent selective handle for the radical-mediated thiol-ene click reaction (TEC). Here we present the development of a novel TEC-mediated photochemical approach for the identification of therapeutically relevant histone and non-histone Kcr proteins. We will use a chemoproteomics approach to detect and identify Kcr proteins in different cell lines. Initially, a selective chemical probe will be designed and synthesised; then proteomics studies will be performed for the identification and characterisation of Kcr proteins, thus leading to the first accurate description of the lysine crotonylome and aiding a better understanding of the role of crotonylation in molecular processes. Moreover, the probe will be used for the identification of non-histone Kcr proteins in a mouse model of cardiac hypertrophy, leading to the discovery of potential biomarkers or therapeutic targets for curing cardiac disease.