Roadblock termination by reb1p restricts cryptic and readthrough transcription

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• Compact genomes face challenges from overlapping transcription.
• Efficient transcription termination is vital for controlling pervasive transcription and preventing interference.
• Yeast RNA polymerase II (RNAPII) termination typically involves nascent RNA recognition by specific factors via two known pathways.

Purpose of the Study:

• To describe a novel mechanism of RNAPII transcription termination.
• To demonstrate the biological significance of this new termination pathway.
• To investigate the role of the transcriptional activator Reb1p in transcription termination.

Main Methods:

• Investigated the interaction of Reb1p with RNAPII.
• Analyzed the ubiquitylation of RNAPII.
• Studied the fate of cryptic transcripts generated by Reb1p-dependent termination.
• Assessed transcriptional interference in the absence of Reb1p.

Main Results:

• Identified Reb1p bound to DNA as a roadblock for RNAPII.
• Demonstrated that RNAPII pausing and ubiquitylation at Reb1p sites trigger termination.
• Showed that Reb1p-dependent termination produces cryptic transcripts degraded by the exosome.
• Observed transcriptional interference between neighboring genes when Reb1p was absent.

Conclusions:

• Reb1p-dependent termination is a significant mechanism for controlling pervasive transcription.
• This roadblock termination prevents transcription through crucial gene regulatory regions.
• The findings highlight the importance of novel termination pathways in maintaining genome stability and gene expression fidelity.