A ubiquitous disordered protein interaction module orchestrates transcription elongation

Area of Science:

• Molecular Biology
• Gene Regulation
• Biochemistry

Background:

• Eukaryotic transcription elongation by RNA polymerase II (RNAP2) involves numerous regulatory factors.
• Understanding the interactions within the transcription machinery is crucial for deciphering gene expression control.

Purpose of the Study:

• To identify and characterize conserved interaction modules within the transcription elongation machinery.
• To elucidate the structural and functional significance of the TFIIS N-terminal domain (TND) and TND-interacting motif (TIM) interaction.

Main Methods:

• Nuclear magnetic resonance (NMR) spectroscopy to determine structural basis of interactions.
• Live-cell microscopy to visualize colocalization in the nuclear environment.
• Mass spectrometry to identify interacting protein complexes.
• Functional assays to assess the impact of disrupting TND-TIM interactions on gene expression and RNAP2 dynamics.

Main Results:

• Identification of a conserved binary interaction module comprising TNDs and TIMs.
• Demonstration that TND-TIM interactions are necessary and sufficient for specific nuclear colocalization.
• Disruption of a single TIM in IWS1 significantly altered gene expression and RNAP2 elongation dynamics.

Conclusions:

• The TND-TIM module is a fundamental conserved interaction surface within the eukaryotic transcription elongation machinery.
• These interactions play a critical role in regulating RNAP2 dynamics and gene expression.
• The findings provide new insights into the molecular mechanisms governing transcription elongation.