A direct interaction between CPF and RNA Pol II links RNA 3' end processing to transcription

Area of Science:

• Molecular Biology
• Gene Expression Regulation
• Biochemistry

Background:

• Transcription termination by RNA polymerase II (RNA Pol II) is coupled to RNA 3' end processing.
• The cleavage and polyadenylation factor (CPF) mediates RNA 3' end processing and RNA Pol II dephosphorylation.
• The precise mechanism linking RNA 3' end processing machinery to transcription remains elusive.

Purpose of the Study:

• To investigate the physical and functional interaction between yeast CPF and RNA Pol II.
• To elucidate the role of CPF-mediated dephosphorylation in RNA Pol II activity and transcription regulation.

Main Methods:

• In vitro reconstitution assays
• Structural studies of RNA Pol II
• Genome-wide analyses in yeast

Main Results:

• Yeast CPF physically and functionally interacts with RNA Pol II.
• CPF-mediated dephosphorylation promotes RNA Pol II stalk-to-stalk homodimerization in vitro.
• Disruption of the dimerization interface causes transcription defects, affecting RNA Pol II abundance across various genomic regions.

Conclusions:

• RNA Pol II dimerization, promoted by CPF, is a key mechanism coupling transcription termination and RNA processing.
• RNA Pol II dimerization may provide a mechanistic basis for the allosteric model of transcription termination.
• This interaction regulates transcription elongation factor binding and overall transcription fidelity.