Linjie Li

As a novel post-translational modification (PTM), lysine 2-hydroxyisobutyrylation (Khib) is considered to regulate gene transcriptional activities in eukaryotic cells; however, the functions of Khib-modified proteins in plants remain unknown. Here, we report that Khib is an evolutionarily-conserved PTM in wheat and its progenitors. A total of 3348 Khib sites on 1074 proteins are identified in common wheat (Triticum aestivum L.) by using affinity purification and mass spectroscopy of 2-hydroxyisobutyrylome. Bioinformatic data indicate that Khib-modified proteins participate in a wide variety of biological and metabolic pathways. Immunoprecipitation confirms that Khib-modified proteins are present endogenously. A comparison of Khib and other main PTMs shows that Khib-modified proteins are simultaneously modified by multiple PTMs. Using mutagenesis experiments and co-immunoprecipitation assays, we demonstrate that Khib on K206 of phosphoglycerate kinase (PGK) is a key regulatory modification for its enzymatic activity, and mutation on K206 affects the interactions of PGK with its substrates. Furthermore, Khib modification of low-molecular-weight proteins is a response to the deacetylase inhibitors nicotinamide and trichostatin. This study provides evidence to promote our current understanding of Khib in wheat plants, including the cooperation between Khib and its metabolic regulation.

Ferroptosis is a promising therapeutic target for injury-related diseases, yet diversity in ferroptosis inhibitors remains limited. In this study, initial structure optimization led us to focus on the bond dissociation enthalpy (BDE) of the N–H bond and the residency time of radical scavengers in a phospholipid bilayer, which may play an important role in ferroptosis inhibition potency. This led to the discovery of compound D1, exhibiting potent ferroptosis inhibition, high radical scavenging, and moderate membrane permeability. D1 demonstrated significant neuroprotection in an oxygen glucose deprivation/reoxygenation (OGD/R) model and reduced infarct volume in an in vivo stroke model upon intravenous treatment. Further screening based on this strategy identified NecroX-7 and Eriodictyol-7-O-glucoside as novel ferroptosis inhibitors with highly polar structural characteristics. This approach bridges the gap between free radical scavengers and ferroptosis inhibitors, providing a foundation for research and insights into novel ferroptosis inhibitor development.