Basal transcription machinery (BTM)

The basal transcription machinery is a sophisticated multi-protein assembly required for the initiation of messenger RNA synthesis by RNA polymerase II in eukaryotes. It comprises RNA polymerase II and a suite of general transcription factors—TFIIA, TFIIB, TFIID, TFIIE, TFIIF, and TFIIH—which assemble into a preinitiation complex (PIC) at gene promoters (Sainsbury et al., 2015; Nature Reviews Molecular Cell Biology). This machinery facilitates the recognition of the TATA box or other promoter elements, the unwinding of the DNA double helix, and the transition of the polymerase into an active elongating state (Roeder, 1996; Trends in Biochemical Sciences). In many diseases, particularly cancer, the basal transcription machinery is hijacked or overactivated to support the rapid growth and survival of malignant cells, a phenomenon often termed transcriptional addiction (Lee & Young, 2013; Cell). Therapeutic strategies have increasingly focused on inhibiting specific components of this machinery, such as the CDK7 or XPB subunits of TFIIH, using small molecules like THZ1 or triptolide to selectively disrupt the transcription of oncogenic drivers (Kwiatkowski et al., 2014; Nature). Despite its potential, the ubiquitous and essential nature of the basal transcription machinery across all cell types poses a significant risk of systemic toxicity, necessitating careful dose management and the identification of specific biomarkers for patient selection (Bradner et al., 2017; Cell). Furthermore, certain viruses, such as HIV-1, exploit the host's basal transcription machinery to replicate their genomes, making it a target for antiviral research (Ott et al., 2011; Science).

Other names

General transcription machineryRNA polymerase II preinitiation complexPICGeneral transcription factorsGTFs

Inhibition of RNA polymerase II activity, inhibition of TFIIH helicase (XPB) activity, or inhibition of CDK7-mediated phosphorylation of the RNA polymerase II C-terminal domain (CTD).