Any given chromosomal activity (e.g., transcription) is governed predominantly by the local epiproteome. However, defining local epiproteomes has been limited by a lack of effective technologies to isolate discrete sections of chromatin and to identify with precision specific proteins and histone posttranslational modifications (PT Ms). We report the use of the Cas9 and guide RNA (gRNA) components of the CRI SPR system for gRNA-directed purification of a discrete section of chromatin. Quantitative mass spectrometry provides for unambiguous identification of proteins and histone PT Ms specifically associated with the enriched chromatin. This CRI SPR -based Chromatin Affinity Purification with Mass Spectrometry (CRI SPR -ChAP-MS) approach revealed changes in the local epiproteome of a promoter during activation of transcription. CRI SPR -ChAP-MS thus has broad applications for discovering molecular components and dynamic regulation of any in vivo activity at a given chromosomal location.
- Affinity purification
- Posttranslational modification
ASJC Scopus subject areas
- Molecular Biology
- Cancer Research