Protein interaction network revealed by quantitative proteomic analysis links TFIIB to multiple aspects of the transcription cycle

• Published in: Biochimica et biophysica acta. Proteins and proteomics Vol. 1872; no. 1; p. 140968
• Main Authors: O'Brien, Michael J., Ansari, Athar
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.01.2024
• Subjects: Budding yeast; Chromatin - genetics; Chromatin - metabolism; Protein Interaction Maps; Proteomic analyses; Proteomics; RNA polymerase II; RNA Polymerase II - genetics; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - metabolism; TFIIB; Transcription; Transcription Factor TFIIB - genetics; Transcription Factor TFIIB - metabolism; TFIIB; Budding yeast; Transcription; Proteomic analyses; RNA polymerase II
• ISSN: 1570-9639; 1878-1454
• DOI: 10.1016/j.bbapap.2023.140968

Although TFIIB is widely regarded as an initiation factor, recent reports have implicated it in multiple aspects of eukaryotic transcription. To investigate the broader role of TFIIB in transcription, we performed quantitative proteomic analysis of yeast TFIIB. We purified two different populations of TFIIB; one from soluble cell lysate, which is not engaged in transcription, and the other from the chromatin fraction which yields the transcriptionally active form of the protein. TFIIB purified from the chromatin exhibits several interactions that explain its non-canonical roles in transcription. RNAPII, TFIIF and TFIIH were the only components of the preinitiation complex with a significant presence in chromatin TFIIB. A notable feature was enrichment of all subunits of CF1 and Rat1 3′ end processing-termination complexes in chromatin-TFIIB preparation. Subunits of the CPF termination complex were also detected in both chromatin and soluble derived TFIIB preparations. These results may explain the presence of TFIIB at the 3′ end of genes during transcription as well as its role in promoter-termination interaction. •Transcriptionally active TFIIB exhibits multiple interactions with protein factors.•These interactions explain multiple roles of TFIIB in transcription cycle.•Notable among these interactions are with 3′ end processing termination factors.•This provides an insight into the role of TFIIB in promoter-terminator interaction.•These interactions may contribute to preferential targeting of TFIIB by viruses.