Regulated post-transcriptional RNA cleavage diversifies the eukaryotic transcriptome.

Area of Science:

• Molecular Biology
• Genomics
• Transcriptomics

Background:

• Eukaryotic transcriptome complexity arises from transcription, splicing, and post-transcriptional modifications.
• Recent findings suggest RNA transcripts undergo cleavage and secondary 5' capping.

Purpose of the Study:

• To investigate the role of post-transcriptional RNA cleavage in transcriptome diversification.
• To determine the regulation and prevalence of RNA cleavage and secondary capping.

Main Methods:

• Analysis of genome-wide histone modification and RNA polymerase II occupancy data.
• Comparison of exonic CAGE tags with tissue-matched PARE data.
• Examination of multiple transcriptomic datasets (SAGE, cDNA, small RNA libraries, deep sequencing).

Main Results:

• Post-transcriptional RNA cleavage generates diverse small and long coding/noncoding RNAs.
• The majority of intraexonic CAGE tags originate from post-transcriptional processing.
• Cleavage and secondary capping are regulated in a developmental- and tissue-specific manner.
• Evidence of prevalent RNA cleavage found across various transcriptomic data types.
• Cleavage products include mRNA variants potentially encoding functional protein isoforms.

Conclusions:

• Post-transcriptional RNA cleavage is a significant mechanism for expanding the eukaryotic transcriptome.
• This process enhances the functional repertoire and regulatory control of RNA molecules.
• RNA cleavage contributes to generating novel functional RNA and protein variants.