Genome-wide analysis of TFIIB’s role in termination of transcription

TL;DR

This study shows that TFIIB, known for starting transcription, also plays a key role in ending it across the genome.

Contribution

The study reveals TFIIB's novel role in transcription termination through genome-wide analysis and interaction studies.

Findings

74% of genes showed increased readthrough in TFIIBsua7-1 mutants compared to wild type.

TFIIB interacts with termination complexes CF1A and Rat1 in wild type but not in the mutant.

ChIP assays showed a 90% decline in termination factor recruitment in the mutant.

Abstract

This study provides evidence that the role of TFIIB extends beyond initiation to include the termination step of transcription. Using GRO-seq analyses, we compared terminator readthrough phenotype in sua7-1 mutant (TFIIBsua7-1) and the isogenic wild type (TFIIBWT) strains. Approximately 74% of genes analyzed exhibited a 2–3-fold increase in readthrough of the poly(A)-termination signal in the TFIIBsua7-1 mutant compared to TFIIBWT cells. Mass spectrometry of affinity purified TFIIB from chromatin fraction found TFIIB exhibiting interaction with CF1A and Rat1 termination complexes in TFIIBWT cells. There was, however, a drastic decrease in TFIIB interaction with CF1A and Rat1 termination complexes in the TFIIBsua7-1 mutant. ChIP assays revealed about 90% decline in recruitment of termination factors in TFIIBsua7-1 mutant compared to wild type cells. The overall conclusion of these results is that TFIIB affects termination of transcription on a genome-wide scale, and TFIIB-termination factor interaction may play a crucial role in the process.

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