Histone Purification Combined with High-Resolution Mass Spectrometry to Examine Histone Post-Translational...

Area of Science:

• Epigenetics and Molecular Biology
• Proteomics and Mass Spectrometry
• Model Organism Research (C. elegans)

Background:

• Histones are crucial for chromatin structure and epigenome regulation, with over 200 known post-translational modifications (PTMs).
• Studying histone PTMs comprehensively requires sophisticated methods, with mass spectrometry (MS)-based approaches gaining prominence for simultaneous quantification.
• Efficient isolation of pure histones is critical for MS analysis, but has been challenging in the model organism Caenorhabditis elegans.

Purpose of the Study:

• To develop an efficient method for isolating pure histones from C. elegans.
• To establish an optimized MS pipeline for accurate relative quantification of histone PTMs in C. elegans.
• To demonstrate the pipeline's utility by analyzing PTM differences in C. elegans strains with varying aging rates.

Main Methods:

• Development of protocols for large-scale C. elegans cultivation, nuclear preparation, and histone extraction/purification.
• Bottom-up mass spectrometry (MS) analysis following histone alkylation and tryptic digestion.
• Data evaluation using a C. elegans-adapted version of the EpiProfile 2.0 software for PTM quantification.

Main Results:

• Successful establishment of a high-yield method for isolating pure histones from C. elegans.
• An optimized MS pipeline capable of accurate relative quantification of numerous histone PTMs.
• Identification of distinct histone PTM profiles correlating with differential aging rates across C. elegans strains.

Conclusions:

• The presented method overcomes challenges in C. elegans histone isolation, facilitating epigenome research.
• The optimized MS pipeline enables detailed analysis of histone PTMs and their biological significance.
• This approach provides insights into the relationship between histone modifications and organismal aging.