Profiling active RNA polymerase II transcription start sites from total RNA by capped small RNA sequencing...

Area of Science:

• Molecular Biology
• Genomics
• Gene Regulation

Background:

• Understanding gene expression requires dynamic mapping of RNA polymerase II transcription initiation.
• Identifying the full spectrum of RNA transcripts, including stable mRNAs and transient enhancer RNAs, is crucial for gene regulation studies.

Purpose of the Study:

• To present a detailed protocol for capped small RNA sequencing (csRNA-seq).
• To enable high-resolution mapping of active transcription initiation and cis-regulatory elements.
• To facilitate the study of gene regulation and transcription dynamics.

Main Methods:

• Isolation of total RNA from various sample types (fresh, frozen, fixed cells, tissues, patient samples).
• Selective enrichment of 5'-capped RNA polymerase II transcripts.
• Library generation and sequencing for high-resolution data analysis.

Main Results:

• csRNA-seq captures initiating stable RNAs (mRNAs, non-coding RNAs) and transient transcripts (enhancer RNAs, promoter divergent RNAs).
• Provides a comprehensive snapshot of active cis-regulatory elements and their properties.
• Demonstrates decoupling of sample collection and processing, broad sample compatibility, and scalability.

Conclusions:

• csRNA-seq offers a sensitive, high-resolution method for studying nascent transcription and gene regulation.
• The protocol is accessible to researchers with minimal nascent transcriptomics experience.
• Enables safe analysis of clinical or pathogenic specimens under standard laboratory conditions.