General transcriptional coactivator and basal transcription machinery complexes

The general transcriptional coactivator and basal transcription machinery complexes represent the core protein assembly required for the transcription of protein-coding genes by RNA polymerase II. This group encompasses the RNA polymerase II enzyme itself, the general transcription factors (TFIIA, TFIIB, TFIID, TFIIE, TFIIF, and TFIIH), and essential coactivators like the Mediator complex and p300/CBP. These components assemble at gene promoters to form the pre-initiation complex (PIC), which is responsible for DNA unwinding, transcription initiation, and the transition to elongation. In many pathological states, particularly in oncology, these complexes are dysregulated or exploited by oncogenic drivers to maintain high levels of gene expression, a phenomenon known as transcriptional addiction. Therapeutic targeting of this machinery typically involves small-molecule inhibitors of associated kinases, such as CDK7 and CDK9, or direct inhibitors of RNA polymerase II. While these agents show promise in treating aggressive cancers and certain viral infections, their development is often limited by a narrow therapeutic window due to the essential role of these complexes in normal cellular homeostasis.

Other names

RNA polymerase II pre-initiation complexBasal transcription factorsTranscriptional co-regulatorsGTF-coactivator complexesRNA polymerase II transcription machinery

Inhibition of RNA polymerase II C-terminal domain (CTD) phosphorylation, disruption of the pre-initiation complex, and inhibition of transcriptional elongation.