Improved Mass Spectrometry-Based Methods Reveal Abundant Propionylation and Tissue-Specific Histone Propionylation...

Area of Science:

• Biochemistry
• Molecular Biology
• Epigenetics

Background:

• Histone posttranslational modifications (PTMs) regulate cellular processes, with aberrant levels linked to diseases like cancer.
• While methylation and acetylation are well-studied, long-chain acylations like propionylation and butyrylation offer insights into metabolic states and gene expression.
• Existing mass spectrometry protocols often fail to identify naturally occurring propionylation and butyrylation.

Purpose of the Study:

• To develop and present improved protocols for the quantitative analysis of histone propionylation and butyrylation.
• To profile these histone acylations across diverse biological contexts, including mouse tissues and human breast cancer samples.
• To investigate the potential of histone acylations as biomarkers for tissue discrimination and disease states.

Main Methods:

• Optimization of sample preparation techniques, including derivatization and protease digestion.
• Application of state-of-the-art mass spectrometry for comprehensive histone PTM analysis.
• Profiling of histone propionylation and butyrylation in seven mouse tissues and human normal and tumor breast samples.

Main Results:

• Successful quantitation of histone propionylation and butyrylation using the developed protocols.
• Generation of a comprehensive map of these modifications in different tissue contexts.
• Demonstration that histone acylations contribute to discriminating between different tissues, even after antibiotic perturbation, and between normal and tumor breast samples.

Conclusions:

• Standard histone PTM analysis is limited by its inability to detect certain acylations.
• The developed methods allow for the analysis of a wider spectrum of histone modifications, including propionylation and butyrylation.
• Profiling a broader range of histone modifications is essential for deeper understanding of their functional roles in cellular processes and disease.