New progress in the study of biological "eraser" enzyme

Researchers from the University of Hong Kong published an important research achievement in life, entitled "identification of 'erasers' for lysine crotonylated stone marks using a chemical protocols approach" In this study, we used chemical proteomics to describe the recognition of h3k4cr (lysine-4 crotonylated stone H3) by 'eraser' enzyme Histone post-translational modification (PTM) plays an important role in the regulation of biological processes such as gene transcription, DNA replication and chromosome separation Enzymes with the function of "writing" or "erasing" catalyze the addition or removal of modifications on histones At the same time, histone "reader" codes recognize specific histone modifications and transform them into different cell projects to establish a variety of cell phenotypes, while the genetic code (DNA) does not change Kyrgyzation of lysine crotonylation (KCR) is a new type of post-translational modification first discovered by scientists of Jingjie biology It is often enriched in active gene promoters and potential enhancers in mammalian cell genome In meiotic male germ cells, KCR is a specific marker of X-linked genes, which indicates that KCR is an important histone marker in the process of male germ cell differentiation However, due to the limitation of the study of catalytic KCR enzyme, there are few studies on the mechanism and function of histone KCR A systematic study of 11 zinc dependent lysine deacetylases that act on a series of C-terminal lysine acetylation peptide segments in humans was carried out Olsen et al Found that the nuclear receptor co repressor complex 1 (hdac3-ncor1) composed of HDAC3 had obvious activity of deacetylase Recently, through the use of radioactive thin-layer chromatography, denu et al Demonstrated that SIRT1 and sirt2 can catalyze the removal of Crotonyl groups from the peptide segment of histone h3k9cr However, this discovery is found on a single peptide substrate, and the catalytic mechanism and the molecular mechanism of substrate recognition are not clear More importantly, both of the above experiments are carried out in vitro, which makes it necessary to identify endogenous histone depassoylase Because the interaction between PTMs and its regulatory enzymes is weak and short, it is difficult to identify the traditional pull down experiment Recently, we report a new method to identify the "readers" of PTM, which is based on stable isotope labeling (SILAC) and cross-linking assisted protein recognition (classpi) This method is used to explore dynamic and transient PTMs and these modified "erasers" The authors also predict that this method can be applied to other modified "eraser" research fields, such as arginine demethylase Through antibody enrichment (PTM Biolabs anti-h3k4cr, anti-h3k27cr, and pan anti crotonyllysine antibodies), the strategy of cross-linking assisted SILAC technology found that SIRT1, sirt2 and SIRT3 could catalyze the hydrolysis of peptides and proteins of histone lysine crotonylation in HeLa cells, and the molecular mechanism of their recognition of KCR was clarified by X-ray crystallography More importantly, SIRT3 can also be used as a scavenging enzyme to regulate the dynamic balance of histone acylation and gene transcription This discovery not only opens the door to detect the physiological function of histone crotonylation, but also provides help to unravel the unknown mechanism of SIRT3 regulating cells (source: Science Network)