Identification of Histone Lysine Acetoacetylation as a Dynamic Post‐Translational Modification Regulated by HBO1

Abstract

Ketone bodies have long been known as a group of lipid‐derived alternative energy sources during glucose shortages. Nevertheless, the molecular mechanisms underlying their non‐metabolic functions remain largely elusive. This study identified acetoacetate as the precursor for lysine acetoacetylation (Kacac), a previously uncharacterized and evolutionarily conserved histone post‐translational modification. This protein modification is comprehensively validated using chemical and biochemical approaches, including HPLC co‐elution and MS/MS analysis using synthetic peptides, Western blot, and isotopic labeling. Histone Kacac can be dynamically regulated by acetoacetate concentration, possibly via acetoacetyl‐CoA. Biochemical studies show that HBO1, traditionally known as an acetyltransferase, can also serve as an acetoacetyltransferase. In addition, 33 Kacac sites are identified on mammalian histones, depicting the landscape of histone Kacac marks across species and organs. In summary, this study thus discovers a physiologically relevant and enzymatically regulated histone mark that sheds light on the non‐metabolic functions of ketone bodies.

Quantitative Pattern of hPTMs by Mass Spectrometry-Based Proteomics with Implications for Triple-Negative Breast Cancer

“…Additionally, simultaneous detection of multiple hPTMs requires multiple membrane washes and successive antibody reincubation steps, making the process very time-consuming. In recent years, a transformative advancement in the form of MS has offered a sensitive and efficient pathway for detecting hPTMs. − For example, Dr. Cuomo et al conducted a profiling of 24 distinct hPTMs of histone . In a similar manner, Dr. Leroy et al reported the abundances of single and combinatorial hPTMs among different cancer cell lines, identifying an enrichment of combinatorial hPTMs containing H3K27 methylation in breast cell lines .…”

Protein Post-Translational Modifications Based on Proteomics: A Potential Regulatory Role in Animal Science

“…Recently, Gao et al utilized several biochemical assays to validate the presence of histone lysine acetoacetylation (Kacac) in humans, mice, and zebrafish and identified 33 Kacac sites on histones. 130 Kacac is regulated via EAA and the ketogenesis pathway. HBO1 is a lysine acetoacetyltransferase through binding acetoacetyl-CoA and key amino acid residues, and HDAC3 is a deacetoacetylase by removing histone acetoacetylation in vitro.…”

“…As another component of ketone bodies, acetoacetate may also serve as a precursor to modify histone lysine, similar to β-hydroxybutyrylation. Recently, Gao et al utilized several biochemical assays to validate the presence of histone lysine acetoacetylation (Kacac) in humans, mice, and zebrafish and identified 33 Kacac sites on histones . Kacac is regulated via EAA and the ketogenesis pathway.…”